Franklin A. Michota, MD, FHM

Most surgical patients who require hospitalization should be considered at high risk for venous thromboembolism (VTE) and be given appropriate prophylaxis. For lower-risk procedures such as knee arthroscopy, prophylaxis is needed for those with individual risk factors such as morbid obesity, limited mobility after surgery, or a history of deep vein thrombosis (DVT) or malignancy. Too often, however, prophylaxis is not provided appropriately or not given at all.

This review surveys the essentials of perioperative VTE prophylaxis and important new developments in the field, which include the 2008 release of new evidence-based clinical practice guidelines on antithrombotic and thrombolytic therapy from the American College of Chest Physicians (ACCP). This 8th edition of the guidelines updates the previous edition, published in 2004, and includes a section by Geerts et al devoted to VTE prevention.¹ Other major guidelines are also discussed, as are developments in VTE-related quality measurement, management of special patient populations (those with renal impairment or morbid obesity), and emerging therapies for VTE prophylaxis.

IMPETUS FOR QUALITY IMPROVEMENT IN VTE

A new seriousness about VTE quality measures

The 8th edition of the ACCP guidelines recommends that every hospital develop a formal, active strategy to consistently identify medical and surgical patients at risk for VTE and to prevent VTE occurrence.¹ Although prior editions of the ACCP guidelines have made this recommendation for more than 2 decades, fewer than 1 in 10 acute care hospitals had any such strategy in place as recently as 5 years ago. Now, however, most US hospitals have implemented such a strategy, thanks to the growing national emphasis on health care quality measurement in recent years.

The Surgical Care Improvement Project (SCIP) has been at the forefront of this recent quality measures movement. SCIP, a joint project of the American Medical Association and federal government agencies, set a goal to reduce surgical complications in the United States by 25% from 2005 to 2010.² Two SCIP process measures relate to improving VTE prophylaxis^2,3:

• The proportion of surgical patients for whom recommended VTE prophylaxis is ordered
• The proportion of surgical patients who actually receive appropriate VTE prophylaxis within 24 hours before or after surgery.

The Joint Commission and the National Quality Forum recently endorsed these two SCIP performance measures for perioperative VTE prophylaxis along with several others relating to VTE treatment.

CMS raises the stakes with reimbursement restrictions

More significantly, the federal government’s Centers for Medicare and Medicaid Services (CMS) will soon refuse to reimburse for hospital treatment of a primary diagnosis of DVT or pulmonary embolism (PE) following recent (within 30 days) total hip or knee arthroplasty. Effective October 1, 2009, a primary VTE diagnosis following these joint replacement procedures will be added to CMS’ current list of “never events,” or hospital-acquired conditions for which CMS will not provide reimbursement because they are considered the result of preventable medical errors. (Notably, treatment of DVT or PE as a secondary diagnosis will still be reimbursed—for example, if a joint replacement patient develops nosocomial pneumonia, is transferred to the intensive care unit, and then develops VTE.) This addition of DVT and PE to the list is highly controversial since these events sometimes develop even if prophylactic therapy is appropriate and aggressive.

Strategies to promote best practices

In the update for the new 8th edition of its guidelines, the ACCP added recommendations on specific ways for hospitals to identify patients at high risk for VTE and ensure that they receive appropriate prophylaxis. These include the use of computer decision-support systems, preprinted orders, and periodic audit and feedback.¹

Researchers at Brigham and Women’s Hospital evaluated the effectiveness of a computer alert system for notifying physicians of newly hospitalized patients at risk for DVT who were not receiving prevention therapy within the first 24 hours of hospital admission.⁴ These patients presumably “fell through the cracks” and warranted prophylaxis but were otherwise not recognized by the health care team. Risk was determined by a scoring system based on multiple variables, including malignancy, previous DVT or PE, hypercoagulability, major surgery, advanced age, obesity, ordered bed rest, and treatment with hormone replacement therapy or oral contraceptives. Study physicians had to acknowledge having received the alert but could choose whether or not to order VTE prophylaxis. Prophylaxis was used in considerably more patients from the intervention group than from a control group of high-risk patients whose physicians did not receive alerts (34% vs 14%, respectively); accordingly, the risk of a symptomatic DVT or PE event at 90 days was reduced by 41% in the intervention group.

Despite this evidence of improved practice under the alert system, the study begs the question of why the percentage of patients at risk for VTE who were given prophylaxis was still so low (34%), demonstrating how much progress in improving practice remains to be achieved.

PROPHYLAXIS STRATEGIES: MATCHING THERAPY TO RISK

A fundamental consideration in determining the degree of VTE prophylaxis that a surgical patient may need is the thromboembolic risk of the procedure itself. Table 1 presents a procedure-based ranking of risk based on recommendations in the 8th edition of the ACCP guidelines.¹ As risk increases, so does the intensity of prophylaxis, with increasing reliance on pharmacologic strategies. The vast majority of patients who are hospitalized for surgery will fall into the moderate- or high-risk categories in Table 1.

A patient’s risk of thrombosis is also influenced by individual risk factors (Table 2),^1,5 many of which are nonmodifiable. A thorough preoperative evaluation is important to reveal “hidden” risk factors such as thrombo­philia and a family or personal history of VTE.

 

 

NONPHARMACOLOGIC PROPHYLAXIS STRATEGIES

Does ambulation prevent DVT?

Although it is commonly accepted that walking prevents DVT, this has never been directly tested. Walking may simply be a marker of health, and healthy people are less prone to develop thromboses. We have almost no evidence to show that forcing an unhealthy person to walk helps prevent DVT. Early ambulation offers many benefits and should be encouraged, but it should not be considered DVT prophylaxis; it is simply good hospital care.

Mechanical devices: Adherence is key

Amaragiri and Lees conducted a systematic literature review of randomized controlled trials evaluating the effectiveness of graduated compression stockings (elastic stockings) for preventing DVT in various groups of hospitalized patients.⁶ The analysis demonstrated a statistically significant reduction in DVT incidence with graduated compression stockings compared with control both among the nine trials in which stockings were used alone (odds ratio = 0.34) and among the seven trials in which stockings were used in addition to another method of thrombo­prophylaxis (odds ratio = 0.24). Although benefit was demonstrated, many of the trials in this review involved patients undergoing gynecologic surgery and date from the 1970s and 1980s (when obesity was less prevalent), so the applicability of their results today may be limited.

The 8th edition of the ACCP guidelines recommends that mechanical methods of VTE prophylaxis be used primarily in patients who are at high risk of bleeding and that careful attention be directed to ensuring their proper use and optimal adherence.¹ The latter point about adherence cannot be emphasized enough, as graduated compression stockings and other mechanical devices have been shown not to be effective unless they are worn at least 18 to 20 hours a day. This degree of adherence is difficult to achieve, as it can severely limit patient mobility and leave patients susceptible to develop­ment of pressure ulcers.

Mechanical compression should be initiated prior to induction of anesthesia and continue intraoperatively and then into the postanesthesia care unit. Orders for use of mechanical devices should include instructions in the patient’s medical chart specifying how—and for how many hours per day—they are to be worn. Not doing so leaves the physician vulnerable to litigation, especially as the ACCP guidelines include language on optimal adherence to these devices (“they should be removed for only a short time each day when the patient is actually walking or for bathing”¹).

Continuous external compression therapy

Newer mechanical device options include a continuous external compression therapy system that allows patients to be mobile while wearing it and provides rhythmic compression that results in good peak venous flows. Ideally such a device could be put on the patient preoperatively and worn during surgery, throughout the hospital stay, and even at home during recovery. Anecdotally, however, I see patients turn these new devices off at the side of the bed just as often as they do with traditional devices.

Vena caval interruption

Vena caval interruption involves placement of a retrievable vena cava filter before surgery and removal some time later; it offers the potential for VTE prophylaxis in patients who could not tolerate even minor amounts of bleeding, such as certain trauma patients. The Eastern Association for the Surgery of Trauma has put forth a consensus recommendation to consider vena caval interruption in high-risk trauma patients who cannot receive pharmacologic prophylaxis.⁷ A randomized trial evaluating the usefulness of vena caval interruption for patients undergoing surgery is needed. For now, this intervention should be regarded as experimental and considered only on a highly individualized basis.

PHARMACOLOGIC PROPHYLAXIS

The ACCP guidelines’ recommendations for pharmacologic VTE prophylaxis in surgical patients are lengthy, and many remain unchanged from prior editions, so this discussion will focus on broad principles and new recommendations adopted in the recent 8th edition.¹Table 3 lists notable new recommendations for patients undergoing specific surgical procedures.

Timing of initiation

Pharmacologic VTE prophylaxis generally should begin 8 to 24 hours postoperatively. Of course, adequate hemostasis is required before initiation, and the net risk/benefit tradeoff with regard to timing of anticoagulant initiation has still not been well studied in many surgical patient populations.

Extended prophylaxis

In the update for the 8th edition of its guidelines, the ACCP added an explicit recommendation for extended outpatient prophylaxis with low-molecular-weight heparin (LMWH) for up to 28 days postoperatively in selected high-risk patients undergoing general or gynecologic surgery, including those with cancer or a history of VTE.¹ This recommendation was based largely on studies of extended prophylaxis in patients with cancer undergoing colorectal surgery.⁸

Increased appreciation of the value of extended VTE prophylaxis after discharge is linked to a growing recognition that DVT and PE episodes in the community setting are often related to a recent hospital stay for either medical illness or surgery. A population-based study found that 59% of all community cases of a first lifetime VTE event in residents of Olmsted County, Minn., over a 15-year period could be linked to current or recent (< 30 days) hospitalization or nursing home residence.⁹ A similar population-based study in the Worcester, Mass., area found that three-fourths of all VTE events in a 3-year period occurred in the outpatient setting.¹⁰ Among patients with these outpatient VTE events, a large proportion had undergone surgery (23%) or hospitalization (37%) in the prior 3 months; among those, 67% experienced their VTE within 1 month of their time in the hospital.

These findings are no surprise, since surgery induces a hypercoagulable state that, when combined with individual risk factors such as obesity, old age, or poor heart function, cannot be assumed to return to baseline on postoperative day 4 or 5 just because the patient is being discharged.

Orthopedic surgery

For patients undergoing major orthopedic procedures, the ACCP guidelines recommend against routine screening for VTE with Doppler ultrasonography before discharge if the patient is asymptomatic.¹ Such screening is not considered cost-effective because asymptomatic clots often are found, for which treatment is uncertain, and proximal clots may be missed, giving a false sense of security.

ACCP recommendations for prophylaxis in patients undergoing orthopedic surgery are summarized in Table 4.¹ As shown, the recommended options for hip and knee replacement and hip fracture surgery are almost exclusively medication-based. The vast majority of patients undergoing these major orthopedic procedures need prophylaxis beyond their typical hospital stay of 3 or 4 days. About 90% of DVTs following knee replacement occur within 2 weeks of surgery, so 10 to 14 days of therapy is probably the best practice in this setting, although a longer period may be justified depending on the patient’s risk profile. For hip replacement, in contrast, 28 to 30 days of prophylaxis is often preferable, since about half of all DVTs in that setting occur more than 2 weeks after surgery.

New to the ACCP guidelines in the 8th edition is the recommendation that patients undergoing knee arthroscopy who have risk factors for VTE (or whose procedure is complicated) should receive 1 week of prophylaxis with LMWH.¹ Also new are recommendations for patients with risk factors undergoing single- or multilevel laminectomy (Table 4).

 

 

Recommendations unchanged in neurosurgery, spinal injury, trauma, burns

Recommendations for neurosurgery remain unchanged from the prior (2004) edition of the ACCP guidelines and are still based on the 2000 meta-analysis by Iorio and Agnelli of LMWH prophylaxis in neurosurgery cases.¹¹ In the United States, the standard is overwhelmingly to use mechanical devices for thromboprophylaxis in neurosurgery, even for patients with cancer.

For prophylaxis in surgical patients with spinal cord injury, multisystem trauma, or burns, LMWH is predominantly used, and the ACCP recommendations are unchanged from 2004.

Drug-specific considerations

LMWH vs vitamin K antagonist. Although vitamin K antagonists (warfarin) still appear in the latest ACCP recommendations,¹ LMWH is preferable. A 2004 meta-analysis of studies comparing vitamin K antagonists with LMWH for prophylaxis in patients undergoing orthopedic surgery found that vitamin K antagonists were associated with more episodes of total DVT (relative risk [RR] = 1.51; 95% CI, 1.27–1.79) and proximal DVT (RR = 1.51; 95% CI, 1.04–2.17) compared with LMWH.¹² No difference was found in rates of wound hematoma or major bleeding. This finding of inferiority for vitamin K antagonists came despite the likelihood that warfarin was more often administered correctly (ie, with dose adjustment to achieve an international normalized ratio [INR] of 2.0 to 3.0 within 72 hours after surgery) in the studies in this analysis than it is in real-world practice.

Fondaparinux. The indirect factor Xa–specific inhibitor fondaparinux has had a surprisingly limited clinical adoption despite having been widely studied and found to be safe and effective. This is likely attributable in part to its 17-hour half-life, which raises concerns that it may take 3 days for its effects to stop if a patient begins to bleed. Large phase 3 studies have found fondaparinux to be equivalent to LMWH in VTE prevention after hip replacement, marginally superior to LMWH after knee replacement, and superior to LMWH following hip fracture repair.¹³ Fondaparinux was associated with an increase in bleeding events and instances of transfusion requirement, but only in one of the studies, which was in the setting of knee replacement surgery.¹⁴

Aspirin not recommended by ACCP. Although aspirin reduces the risk of VTE, practice guidelines from both the ACCP¹ and the International Union of Angiology¹⁵ contain no recommendation for its use as prophylaxis because it is considered less effective and more risky than other therapies. In contrast, clinical practice guidelines from the American Academy of Orthopaedic Surgeons suggest that aspirin is reasonable for VTE prophylaxis.¹⁶ The varying recommendations reflect differences in perspective among these different specialties.

Aspirin has the advantages of ease of use and low cost, but it is clearly not the best evidence-based approach for VTE prophylaxis. The only recent randomized trial evidence in support of aspirin comes from the Pulmonary Embolism Prevention trial, a study with a flawed design involving more than 13,000 patients undergoing surgery for hip fracture or elective arthroplasty in five countries.¹⁷ Patients were randomized to receive aspirin 160 mg daily or placebo for 35 days along with any other prophylaxis deemed necessary (an important potential confounder). Aspirin was associated with an absolute reduction in symptomatic events of less than 1% relative to placebo, and no benefit was observed within the first week. The best results with aspirin were among patients with hip fracture. No benefit was shown among patients undergoing hip arthroplasty or knee arthroplasty; in those groups, both the aspirin and placebo recipients were also treated with LMWH. An absolute increase in rates of wound bleeding (0.6% increase) and gastrointestinal bleeding (1.0% increase) was observed in the aspirin group. The absolute increase in complications was greater than the absolute reduction in episodes of symptomatic DVT: for every episode of symptomatic DVT averted, one wound bleed and 10 gastrointestinal bleeds occurred.

SPECIAL PATIENT POPULATIONS

Renal impairment

The 8th edition of the ACCP guidelines recommends that renal function be kept in mind when considering LMWH, fondaparinux, and other antithrombotic drugs that are cleared by the kidneys. Fondaparinux and LMWH can bioaccumulate in patients with renal insufficiency, who have a higher risk of bleeding to begin with, thereby compounding the risk. Options for patients with renal compromise include avoiding drugs that bioaccumulate, using a lower dosage, and monitoring the drug level or anticoagulant effect.¹

Fondaparinux is explicitly contraindicated in patients with low body weight (< 50 kg) or renal impairment (creatinine clearance < 30 mL/min). Renal function should be assessed periodically in any patients receiving the drug.¹⁸

I also would not use fondaparinux or LMWH in patients with rapidly changing renal function. For patients with chronic, stable renal impairment, one can reduce the dose of LMWH empirically; one LMWH, enoxaparin, has specific dosing guidelines in its package insert (one-third reduction in dose), but this option does not hold for patients with rapidly changing renal function.¹⁹

Obesity

The 8th edition of the ACCP guidelines recommends weight-based dosing of thromboprophylactic agents in obese patients. The guidelines particularly recommend that patients undergoing inpatient bariatric surgery be given higher doses of LMWH or unfractionated heparin.^1,20

Frederiksen et al measured the anticoagulant effect of a single fixed dose of a LMWH (using anti-factor Xa heparin activity levels) and found that it was dependent on body weight.²¹ This suggests that fixed doses that are effective in normal-weight patients may have no detectable anti-coagulant effect in patients with very high body weight.

Weight-based dosing: mounting nonprospective evidence. Weight-based dosage adjustment for the morbidly obese has not been directly studied in a prospective, randomized fashion. A nonrandomized study by Scholten et al compared two regimens of enoxaparin (30 mg twice daily vs 40 mg twice daily) among 481 obese patients undergoing bariatric surgery; each regimen was used along with mechanical thromboprophylaxis.²² They found that the higher-dose regimen was associated with significantly fewer postoperative DVT complications (0.6% vs 5.4%; P < .01) without an increase in bleeding complications.

Separately, Shepherd et al used weight-adjusted doses of unfractionated heparin (started on the evening of surgery) to achieve subtherapeutic peak anti–factor Xa heparin activity levels of 0.11 to 0.25 IU/mL in a series of 700 patients undergoing laparoscopic gastric bypass surgery.²³ The resulting doses were greater than those in traditional fixed-rate protocols, but rates of bleeding and VTE events were low and comparable to those reported in patients receiving standard doses. 

Don’t rule out multimodal approaches. Multimodal prophylaxis can also be used in obese patients and need not be abandoned as a result of size considerations. For instance, two intermittent compression therapy devices can be pieced together with a Velcro binder if a single device is too small to be worn.

 

 

EMERGING ANTICOAGULANT OPTIONS

For many years, unfractionated heparin was the only available parenteral anticoagulant. While heparin has broad anticoagulant properties, it also has well-established limitations, including the need for parenteral delivery, recent problems related to contamination (it is derived from pig intestines), and of course heparin-induced thrombocytopenia (HIT). HIT is an immune-mediated form of platelet activation that can lead to widespread thrombosis throughout the body. It is more commonly associated with venous thrombosis, but arterial events with limb-threatening ischemia may also occur. LMWH is associated with a reduced risk of HIT, but LMWH does not avoid the risk entirely.

Beyond the issue of avoiding HIT, newer anticoagulant therapies are being developed with the aim of oral administration and more targeted inhibition of coagulation factors IIa (thrombin) and Xa.²⁴

Oral direct thrombin inhibitors

One of the two most promising classes of emerging anticoagulants is the direct thrombin inhibitors, most of which are being developed for oral administration. There were high hopes for the initial compound in this class, ximelagatran, but it was abandoned about 5 years ago because of hepatotoxicity.

Dabigatran is the direct thrombin inhibitor furthest along in development today. Currently approved in Europe for prevention of VTE in patients undergoing total hip or knee replacement surgery, dabigatran is likely to be available soon in the United States. It is administered orally, has a rapid onset of action (< 1 hour), and has a predictable anticoagulant response that requires no monitoring.²⁴ Because dabigatran is excreted essentially unchanged by the kidneys and may bioaccumulate, it should not be used in patients with renal impairment or rapidly changing renal function.

In phase 3 clinical trials for VTE prevention in knee replacement surgery, dabigatran was at least as effective as enoxaparin 40 mg once daily and had a comparable safety profile,²⁵ but it was slightly less effective than enoxaparin 30 mg twice daily.²⁶ In a phase 3 trial in patients under­going hip replacement surgery, dabigatran was equivalent in efficacy and safety to enoxaparin 40 mg once daily.²⁷

Oral direct factor Xa inhibitors

A key rationale for direct inhibition of factor Xa is that it results in inhibition of thrombin production on the activated platelet. Whereas fondaparinux is an indirect inhibitor of factor Xa, direct factor Xa inhibitors offer an advantage in that they inhibit factor Xa within the prothrombinase complex, which occurs on the surface of a platelet and is the main site for thrombin development (very little thrombin is actually produced on endothelial cells). Recall the adage that “thrombin begets more thrombin”: it activates not only platelets but the intrinsic and extrinsic pathways.²⁸

Factor Xa may be a better target than thrombin for a number of other reasons:

• Factor Xa is believed to have few functions (compared with thrombin) outside of coagulation

• In vitro studies show that factor Xa has a wider therapeutic window than thrombin, which translates to greater separation between drug levels that will confer efficacy and bleeding
• Thrombin inhibitors are associated with rebound thrombin generation (there is no evidence of this with factor Xa inhibitors)
• The efficacy of heparin-based anticoagulants improves as selectivity for factor Xa increases (unfractionated heparin is less effective than LMWH, which is less effective than fondaparinux).

Two direct factor Xa inhibitors—both administered orally—are far along in development, as detailed below.

Apixaban has shown promise, but the phase 3 ADVANCE-1 study of apixaban for VTE prevention in patients undergoing knee surgery did not meet statistical criteria for noninferiority compared with enoxaparin 30 mg twice daily.²⁹ This prompted a delay in regulatory filings for apixaban in the United States, and the drug’s prospects for approval for VTE prevention may be unclear until release of results from two other comparative phase 3 trials with enoxaparin in 2009 and 2010.

Rivaroxaban is more likely to become clinically available soon, in light of recent results from the phase 3 RECORD4 trial demonstrating that it was significantly superior to enoxaparin 30 mg twice daily in preventing VTE following knee replacement surgery with comparable rates of major bleeding.³⁰

DISCUSSION

Question from the audience: Some surgeons in my hospital prescribe warfarin immediately after surgery without a bridge of LMWH. Is that appropriate?

Dr. Michota: Warfarin is an option for prophylaxis in orthopedic surgery, beginning on the day of surgery. It could even be started the day before surgery, but the dose should be monitored to achieve an INR between 2.0 and 3.0 within 72 hours of the procedure. If the INR is not in this optimum range, prophylactic doses of LMWH can be given until it is therapeutic.

Follow-up question: In practice, do you actually encourage INR monitoring? Usually we just put patients on a certain dose without monitoring. When we do check the INR, it’s usually 1.4 or 1.5.

Dr. Michota: Warfarin was shown to be effective in reducing VTE risk in orthopedic surgery with dose adjustment based on INR monitoring. On that basis, warfarin remains in the guideline recommendations. Unmonitored, warfarin has not been shown to reduce risk, so to give it that way would not be evidence-based.

Question from the audience: I work with several plastic surgeons who use compression stockings intraoperatively because they’ve heard of several patients who developed a PE during surgery. Is there any benefit to using compression stockings for 2 to 3 hours and then sending the patient home?

Dr. Michota: I don’t know. Theoretically, a device that is on and working before induction may reduce stasis.

The plastic surgery societies do have guidelines. Risk depends on the type of plastic surgery procedure; for example, risk probably increases due to inflammation in procedures that involve scraping the fat pads.

This is an area where we don’t have much data. These patients may be at risk, but we don’t know the best way to mitigate it. It is important that risks be discussed with patients in the informed-consent process and be documented. If the surgeon thinks it is reasonable to give pharmacologic prophylaxis after surgery, I wouldn’t hesitate to do that, but any form of bleeding in the setting of plastic surgery is catastrophic because it defeats the reason for which the surgery was done in the first place.

Question from the audience: How do the guidelines address being aggressive with pharmacologic thromboprophylaxis when a patient is already taking dual antiplatelet therapy?

Dr. Michota: For patients with an indication for VTE prophylaxis in a setting for which there is a specific strategy, the ACCP guidelines recommend that they be put on that regimen whether they are on antiplatelet agents or not. For example, consider a high-risk patient having colorectal surgery who should get unfractionated heparin or LMWH postoperatively and who is currently taking clopidogrel and aspirin. There is no evidence that the dual aspirin–clopidogrel therapy alone is effective in decreasing the risk of DVT. However, we do know that if we add on additional agents, the risk of bleeding is increased. The guidelines consider risk and benefit, and they recommend adding the agents that we know work to prevent DVT.

Question from the audience: You briefly mentioned prophylaxis for knee arthroscopy, which is the most frequently performed orthopedic procedure. Do these recommendations apply to all patients undergoing knee arthroscopy?

Dr. Michota: No. Prophylaxis is indicated only for patients with what the ACCP considers to be additional risk factors for thrombosis. They didn’t specify which risk factors, but good indications for prophylaxis would include morbid obesity, limited mobility after the procedure, a personal history of DVT, features of stasis noted on physical examination, stasis dermatitis (or other features that could indicate prior thrombosis), advanced age, and malignancy. If a patient undergoing knee arthroscopy has other nonmodifiable risk factors, you should also think about prophylaxis. But the vast majority of patients do not need it.

Question from the audience: I’m an academic hospitalist who works closely with orthopedic surgeons. Certain surgeons will only use aspirin for prophylaxis, and it is nonnegotiable. Where does that leave me from a medicolegal standpoint? Our model is to follow ACCP recommendations, but these orthopedic surgeons still use only aspirin.

Dr. Michota: You must do everything you can to come to a consensus with your surgeon colleagues. If you are uncomfortable, as a group you must say to the surgeons, “We are uncomfortable. This is how we view the data. How do you view the data?” If they answer, “We’re doing it because it’s easy, and the American Academy of Orthopaedic Surgeons says we can do it,” I don’t have a good response. But it is more likely that their use of aspirin is based on their own observations; they may not see many clots. Of course, the problem with observational data is that the numbers are not large and they are not generated in a randomized and prospective fashion. Perhaps you can come to some middle ground, but you could always make the difficult choice and say, “I’m just not going to follow your patients.”

Most surgical patients who require hospitalization should be considered at high risk for venous thromboembolism (VTE) and be given appropriate prophylaxis. For lower-risk procedures such as knee arthroscopy, prophylaxis is needed for those with individual risk factors such as morbid obesity, limited mobility after surgery, or a history of deep vein thrombosis (DVT) or malignancy. Too often, however, prophylaxis is not provided appropriately or not given at all.

This review surveys the essentials of perioperative VTE prophylaxis and important new developments in the field, which include the 2008 release of new evidence-based clinical practice guidelines on antithrombotic and thrombolytic therapy from the American College of Chest Physicians (ACCP). This 8th edition of the guidelines updates the previous edition, published in 2004, and includes a section by Geerts et al devoted to VTE prevention.¹ Other major guidelines are also discussed, as are developments in VTE-related quality measurement, management of special patient populations (those with renal impairment or morbid obesity), and emerging therapies for VTE prophylaxis.

IMPETUS FOR QUALITY IMPROVEMENT IN VTE

A new seriousness about VTE quality measures

The 8th edition of the ACCP guidelines recommends that every hospital develop a formal, active strategy to consistently identify medical and surgical patients at risk for VTE and to prevent VTE occurrence.¹ Although prior editions of the ACCP guidelines have made this recommendation for more than 2 decades, fewer than 1 in 10 acute care hospitals had any such strategy in place as recently as 5 years ago. Now, however, most US hospitals have implemented such a strategy, thanks to the growing national emphasis on health care quality measurement in recent years.

The Surgical Care Improvement Project (SCIP) has been at the forefront of this recent quality measures movement. SCIP, a joint project of the American Medical Association and federal government agencies, set a goal to reduce surgical complications in the United States by 25% from 2005 to 2010.² Two SCIP process measures relate to improving VTE prophylaxis^2,3:

• The proportion of surgical patients for whom recommended VTE prophylaxis is ordered
• The proportion of surgical patients who actually receive appropriate VTE prophylaxis within 24 hours before or after surgery.

The Joint Commission and the National Quality Forum recently endorsed these two SCIP performance measures for perioperative VTE prophylaxis along with several others relating to VTE treatment.

CMS raises the stakes with reimbursement restrictions

More significantly, the federal government’s Centers for Medicare and Medicaid Services (CMS) will soon refuse to reimburse for hospital treatment of a primary diagnosis of DVT or pulmonary embolism (PE) following recent (within 30 days) total hip or knee arthroplasty. Effective October 1, 2009, a primary VTE diagnosis following these joint replacement procedures will be added to CMS’ current list of “never events,” or hospital-acquired conditions for which CMS will not provide reimbursement because they are considered the result of preventable medical errors. (Notably, treatment of DVT or PE as a secondary diagnosis will still be reimbursed—for example, if a joint replacement patient develops nosocomial pneumonia, is transferred to the intensive care unit, and then develops VTE.) This addition of DVT and PE to the list is highly controversial since these events sometimes develop even if prophylactic therapy is appropriate and aggressive.

Strategies to promote best practices

In the update for the new 8th edition of its guidelines, the ACCP added recommendations on specific ways for hospitals to identify patients at high risk for VTE and ensure that they receive appropriate prophylaxis. These include the use of computer decision-support systems, preprinted orders, and periodic audit and feedback.¹

Researchers at Brigham and Women’s Hospital evaluated the effectiveness of a computer alert system for notifying physicians of newly hospitalized patients at risk for DVT who were not receiving prevention therapy within the first 24 hours of hospital admission.⁴ These patients presumably “fell through the cracks” and warranted prophylaxis but were otherwise not recognized by the health care team. Risk was determined by a scoring system based on multiple variables, including malignancy, previous DVT or PE, hypercoagulability, major surgery, advanced age, obesity, ordered bed rest, and treatment with hormone replacement therapy or oral contraceptives. Study physicians had to acknowledge having received the alert but could choose whether or not to order VTE prophylaxis. Prophylaxis was used in considerably more patients from the intervention group than from a control group of high-risk patients whose physicians did not receive alerts (34% vs 14%, respectively); accordingly, the risk of a symptomatic DVT or PE event at 90 days was reduced by 41% in the intervention group.

Despite this evidence of improved practice under the alert system, the study begs the question of why the percentage of patients at risk for VTE who were given prophylaxis was still so low (34%), demonstrating how much progress in improving practice remains to be achieved.

PROPHYLAXIS STRATEGIES: MATCHING THERAPY TO RISK

A fundamental consideration in determining the degree of VTE prophylaxis that a surgical patient may need is the thromboembolic risk of the procedure itself. Table 1 presents a procedure-based ranking of risk based on recommendations in the 8th edition of the ACCP guidelines.¹ As risk increases, so does the intensity of prophylaxis, with increasing reliance on pharmacologic strategies. The vast majority of patients who are hospitalized for surgery will fall into the moderate- or high-risk categories in Table 1.

A patient’s risk of thrombosis is also influenced by individual risk factors (Table 2),^1,5 many of which are nonmodifiable. A thorough preoperative evaluation is important to reveal “hidden” risk factors such as thrombo­philia and a family or personal history of VTE.

 

 

NONPHARMACOLOGIC PROPHYLAXIS STRATEGIES

Does ambulation prevent DVT?

Although it is commonly accepted that walking prevents DVT, this has never been directly tested. Walking may simply be a marker of health, and healthy people are less prone to develop thromboses. We have almost no evidence to show that forcing an unhealthy person to walk helps prevent DVT. Early ambulation offers many benefits and should be encouraged, but it should not be considered DVT prophylaxis; it is simply good hospital care.

Mechanical devices: Adherence is key

Amaragiri and Lees conducted a systematic literature review of randomized controlled trials evaluating the effectiveness of graduated compression stockings (elastic stockings) for preventing DVT in various groups of hospitalized patients.⁶ The analysis demonstrated a statistically significant reduction in DVT incidence with graduated compression stockings compared with control both among the nine trials in which stockings were used alone (odds ratio = 0.34) and among the seven trials in which stockings were used in addition to another method of thrombo­prophylaxis (odds ratio = 0.24). Although benefit was demonstrated, many of the trials in this review involved patients undergoing gynecologic surgery and date from the 1970s and 1980s (when obesity was less prevalent), so the applicability of their results today may be limited.

The 8th edition of the ACCP guidelines recommends that mechanical methods of VTE prophylaxis be used primarily in patients who are at high risk of bleeding and that careful attention be directed to ensuring their proper use and optimal adherence.¹ The latter point about adherence cannot be emphasized enough, as graduated compression stockings and other mechanical devices have been shown not to be effective unless they are worn at least 18 to 20 hours a day. This degree of adherence is difficult to achieve, as it can severely limit patient mobility and leave patients susceptible to develop­ment of pressure ulcers.

Mechanical compression should be initiated prior to induction of anesthesia and continue intraoperatively and then into the postanesthesia care unit. Orders for use of mechanical devices should include instructions in the patient’s medical chart specifying how—and for how many hours per day—they are to be worn. Not doing so leaves the physician vulnerable to litigation, especially as the ACCP guidelines include language on optimal adherence to these devices (“they should be removed for only a short time each day when the patient is actually walking or for bathing”¹).

Continuous external compression therapy

Newer mechanical device options include a continuous external compression therapy system that allows patients to be mobile while wearing it and provides rhythmic compression that results in good peak venous flows. Ideally such a device could be put on the patient preoperatively and worn during surgery, throughout the hospital stay, and even at home during recovery. Anecdotally, however, I see patients turn these new devices off at the side of the bed just as often as they do with traditional devices.

Vena caval interruption

Vena caval interruption involves placement of a retrievable vena cava filter before surgery and removal some time later; it offers the potential for VTE prophylaxis in patients who could not tolerate even minor amounts of bleeding, such as certain trauma patients. The Eastern Association for the Surgery of Trauma has put forth a consensus recommendation to consider vena caval interruption in high-risk trauma patients who cannot receive pharmacologic prophylaxis.⁷ A randomized trial evaluating the usefulness of vena caval interruption for patients undergoing surgery is needed. For now, this intervention should be regarded as experimental and considered only on a highly individualized basis.

PHARMACOLOGIC PROPHYLAXIS

The ACCP guidelines’ recommendations for pharmacologic VTE prophylaxis in surgical patients are lengthy, and many remain unchanged from prior editions, so this discussion will focus on broad principles and new recommendations adopted in the recent 8th edition.¹Table 3 lists notable new recommendations for patients undergoing specific surgical procedures.

Timing of initiation

Pharmacologic VTE prophylaxis generally should begin 8 to 24 hours postoperatively. Of course, adequate hemostasis is required before initiation, and the net risk/benefit tradeoff with regard to timing of anticoagulant initiation has still not been well studied in many surgical patient populations.

Extended prophylaxis

In the update for the 8th edition of its guidelines, the ACCP added an explicit recommendation for extended outpatient prophylaxis with low-molecular-weight heparin (LMWH) for up to 28 days postoperatively in selected high-risk patients undergoing general or gynecologic surgery, including those with cancer or a history of VTE.¹ This recommendation was based largely on studies of extended prophylaxis in patients with cancer undergoing colorectal surgery.⁸

Increased appreciation of the value of extended VTE prophylaxis after discharge is linked to a growing recognition that DVT and PE episodes in the community setting are often related to a recent hospital stay for either medical illness or surgery. A population-based study found that 59% of all community cases of a first lifetime VTE event in residents of Olmsted County, Minn., over a 15-year period could be linked to current or recent (< 30 days) hospitalization or nursing home residence.⁹ A similar population-based study in the Worcester, Mass., area found that three-fourths of all VTE events in a 3-year period occurred in the outpatient setting.¹⁰ Among patients with these outpatient VTE events, a large proportion had undergone surgery (23%) or hospitalization (37%) in the prior 3 months; among those, 67% experienced their VTE within 1 month of their time in the hospital.

These findings are no surprise, since surgery induces a hypercoagulable state that, when combined with individual risk factors such as obesity, old age, or poor heart function, cannot be assumed to return to baseline on postoperative day 4 or 5 just because the patient is being discharged.

Orthopedic surgery

For patients undergoing major orthopedic procedures, the ACCP guidelines recommend against routine screening for VTE with Doppler ultrasonography before discharge if the patient is asymptomatic.¹ Such screening is not considered cost-effective because asymptomatic clots often are found, for which treatment is uncertain, and proximal clots may be missed, giving a false sense of security.

ACCP recommendations for prophylaxis in patients undergoing orthopedic surgery are summarized in Table 4.¹ As shown, the recommended options for hip and knee replacement and hip fracture surgery are almost exclusively medication-based. The vast majority of patients undergoing these major orthopedic procedures need prophylaxis beyond their typical hospital stay of 3 or 4 days. About 90% of DVTs following knee replacement occur within 2 weeks of surgery, so 10 to 14 days of therapy is probably the best practice in this setting, although a longer period may be justified depending on the patient’s risk profile. For hip replacement, in contrast, 28 to 30 days of prophylaxis is often preferable, since about half of all DVTs in that setting occur more than 2 weeks after surgery.

New to the ACCP guidelines in the 8th edition is the recommendation that patients undergoing knee arthroscopy who have risk factors for VTE (or whose procedure is complicated) should receive 1 week of prophylaxis with LMWH.¹ Also new are recommendations for patients with risk factors undergoing single- or multilevel laminectomy (Table 4).

 

 

Recommendations unchanged in neurosurgery, spinal injury, trauma, burns

Recommendations for neurosurgery remain unchanged from the prior (2004) edition of the ACCP guidelines and are still based on the 2000 meta-analysis by Iorio and Agnelli of LMWH prophylaxis in neurosurgery cases.¹¹ In the United States, the standard is overwhelmingly to use mechanical devices for thromboprophylaxis in neurosurgery, even for patients with cancer.

For prophylaxis in surgical patients with spinal cord injury, multisystem trauma, or burns, LMWH is predominantly used, and the ACCP recommendations are unchanged from 2004.

Drug-specific considerations

LMWH vs vitamin K antagonist. Although vitamin K antagonists (warfarin) still appear in the latest ACCP recommendations,¹ LMWH is preferable. A 2004 meta-analysis of studies comparing vitamin K antagonists with LMWH for prophylaxis in patients undergoing orthopedic surgery found that vitamin K antagonists were associated with more episodes of total DVT (relative risk [RR] = 1.51; 95% CI, 1.27–1.79) and proximal DVT (RR = 1.51; 95% CI, 1.04–2.17) compared with LMWH.¹² No difference was found in rates of wound hematoma or major bleeding. This finding of inferiority for vitamin K antagonists came despite the likelihood that warfarin was more often administered correctly (ie, with dose adjustment to achieve an international normalized ratio [INR] of 2.0 to 3.0 within 72 hours after surgery) in the studies in this analysis than it is in real-world practice.

Fondaparinux. The indirect factor Xa–specific inhibitor fondaparinux has had a surprisingly limited clinical adoption despite having been widely studied and found to be safe and effective. This is likely attributable in part to its 17-hour half-life, which raises concerns that it may take 3 days for its effects to stop if a patient begins to bleed. Large phase 3 studies have found fondaparinux to be equivalent to LMWH in VTE prevention after hip replacement, marginally superior to LMWH after knee replacement, and superior to LMWH following hip fracture repair.¹³ Fondaparinux was associated with an increase in bleeding events and instances of transfusion requirement, but only in one of the studies, which was in the setting of knee replacement surgery.¹⁴

Aspirin not recommended by ACCP. Although aspirin reduces the risk of VTE, practice guidelines from both the ACCP¹ and the International Union of Angiology¹⁵ contain no recommendation for its use as prophylaxis because it is considered less effective and more risky than other therapies. In contrast, clinical practice guidelines from the American Academy of Orthopaedic Surgeons suggest that aspirin is reasonable for VTE prophylaxis.¹⁶ The varying recommendations reflect differences in perspective among these different specialties.

Aspirin has the advantages of ease of use and low cost, but it is clearly not the best evidence-based approach for VTE prophylaxis. The only recent randomized trial evidence in support of aspirin comes from the Pulmonary Embolism Prevention trial, a study with a flawed design involving more than 13,000 patients undergoing surgery for hip fracture or elective arthroplasty in five countries.¹⁷ Patients were randomized to receive aspirin 160 mg daily or placebo for 35 days along with any other prophylaxis deemed necessary (an important potential confounder). Aspirin was associated with an absolute reduction in symptomatic events of less than 1% relative to placebo, and no benefit was observed within the first week. The best results with aspirin were among patients with hip fracture. No benefit was shown among patients undergoing hip arthroplasty or knee arthroplasty; in those groups, both the aspirin and placebo recipients were also treated with LMWH. An absolute increase in rates of wound bleeding (0.6% increase) and gastrointestinal bleeding (1.0% increase) was observed in the aspirin group. The absolute increase in complications was greater than the absolute reduction in episodes of symptomatic DVT: for every episode of symptomatic DVT averted, one wound bleed and 10 gastrointestinal bleeds occurred.

SPECIAL PATIENT POPULATIONS

Renal impairment

The 8th edition of the ACCP guidelines recommends that renal function be kept in mind when considering LMWH, fondaparinux, and other antithrombotic drugs that are cleared by the kidneys. Fondaparinux and LMWH can bioaccumulate in patients with renal insufficiency, who have a higher risk of bleeding to begin with, thereby compounding the risk. Options for patients with renal compromise include avoiding drugs that bioaccumulate, using a lower dosage, and monitoring the drug level or anticoagulant effect.¹

Fondaparinux is explicitly contraindicated in patients with low body weight (< 50 kg) or renal impairment (creatinine clearance < 30 mL/min). Renal function should be assessed periodically in any patients receiving the drug.¹⁸

I also would not use fondaparinux or LMWH in patients with rapidly changing renal function. For patients with chronic, stable renal impairment, one can reduce the dose of LMWH empirically; one LMWH, enoxaparin, has specific dosing guidelines in its package insert (one-third reduction in dose), but this option does not hold for patients with rapidly changing renal function.¹⁹

Obesity

The 8th edition of the ACCP guidelines recommends weight-based dosing of thromboprophylactic agents in obese patients. The guidelines particularly recommend that patients undergoing inpatient bariatric surgery be given higher doses of LMWH or unfractionated heparin.^1,20

Frederiksen et al measured the anticoagulant effect of a single fixed dose of a LMWH (using anti-factor Xa heparin activity levels) and found that it was dependent on body weight.²¹ This suggests that fixed doses that are effective in normal-weight patients may have no detectable anti-coagulant effect in patients with very high body weight.

Weight-based dosing: mounting nonprospective evidence. Weight-based dosage adjustment for the morbidly obese has not been directly studied in a prospective, randomized fashion. A nonrandomized study by Scholten et al compared two regimens of enoxaparin (30 mg twice daily vs 40 mg twice daily) among 481 obese patients undergoing bariatric surgery; each regimen was used along with mechanical thromboprophylaxis.²² They found that the higher-dose regimen was associated with significantly fewer postoperative DVT complications (0.6% vs 5.4%; P < .01) without an increase in bleeding complications.

Separately, Shepherd et al used weight-adjusted doses of unfractionated heparin (started on the evening of surgery) to achieve subtherapeutic peak anti–factor Xa heparin activity levels of 0.11 to 0.25 IU/mL in a series of 700 patients undergoing laparoscopic gastric bypass surgery.²³ The resulting doses were greater than those in traditional fixed-rate protocols, but rates of bleeding and VTE events were low and comparable to those reported in patients receiving standard doses. 

Don’t rule out multimodal approaches. Multimodal prophylaxis can also be used in obese patients and need not be abandoned as a result of size considerations. For instance, two intermittent compression therapy devices can be pieced together with a Velcro binder if a single device is too small to be worn.

 

 

EMERGING ANTICOAGULANT OPTIONS

For many years, unfractionated heparin was the only available parenteral anticoagulant. While heparin has broad anticoagulant properties, it also has well-established limitations, including the need for parenteral delivery, recent problems related to contamination (it is derived from pig intestines), and of course heparin-induced thrombocytopenia (HIT). HIT is an immune-mediated form of platelet activation that can lead to widespread thrombosis throughout the body. It is more commonly associated with venous thrombosis, but arterial events with limb-threatening ischemia may also occur. LMWH is associated with a reduced risk of HIT, but LMWH does not avoid the risk entirely.

Beyond the issue of avoiding HIT, newer anticoagulant therapies are being developed with the aim of oral administration and more targeted inhibition of coagulation factors IIa (thrombin) and Xa.²⁴

Oral direct thrombin inhibitors

One of the two most promising classes of emerging anticoagulants is the direct thrombin inhibitors, most of which are being developed for oral administration. There were high hopes for the initial compound in this class, ximelagatran, but it was abandoned about 5 years ago because of hepatotoxicity.

Dabigatran is the direct thrombin inhibitor furthest along in development today. Currently approved in Europe for prevention of VTE in patients undergoing total hip or knee replacement surgery, dabigatran is likely to be available soon in the United States. It is administered orally, has a rapid onset of action (< 1 hour), and has a predictable anticoagulant response that requires no monitoring.²⁴ Because dabigatran is excreted essentially unchanged by the kidneys and may bioaccumulate, it should not be used in patients with renal impairment or rapidly changing renal function.

In phase 3 clinical trials for VTE prevention in knee replacement surgery, dabigatran was at least as effective as enoxaparin 40 mg once daily and had a comparable safety profile,²⁵ but it was slightly less effective than enoxaparin 30 mg twice daily.²⁶ In a phase 3 trial in patients under­going hip replacement surgery, dabigatran was equivalent in efficacy and safety to enoxaparin 40 mg once daily.²⁷

Oral direct factor Xa inhibitors

A key rationale for direct inhibition of factor Xa is that it results in inhibition of thrombin production on the activated platelet. Whereas fondaparinux is an indirect inhibitor of factor Xa, direct factor Xa inhibitors offer an advantage in that they inhibit factor Xa within the prothrombinase complex, which occurs on the surface of a platelet and is the main site for thrombin development (very little thrombin is actually produced on endothelial cells). Recall the adage that “thrombin begets more thrombin”: it activates not only platelets but the intrinsic and extrinsic pathways.²⁸

Factor Xa may be a better target than thrombin for a number of other reasons:

• Factor Xa is believed to have few functions (compared with thrombin) outside of coagulation

• In vitro studies show that factor Xa has a wider therapeutic window than thrombin, which translates to greater separation between drug levels that will confer efficacy and bleeding
• Thrombin inhibitors are associated with rebound thrombin generation (there is no evidence of this with factor Xa inhibitors)
• The efficacy of heparin-based anticoagulants improves as selectivity for factor Xa increases (unfractionated heparin is less effective than LMWH, which is less effective than fondaparinux).

Two direct factor Xa inhibitors—both administered orally—are far along in development, as detailed below.

Apixaban has shown promise, but the phase 3 ADVANCE-1 study of apixaban for VTE prevention in patients undergoing knee surgery did not meet statistical criteria for noninferiority compared with enoxaparin 30 mg twice daily.²⁹ This prompted a delay in regulatory filings for apixaban in the United States, and the drug’s prospects for approval for VTE prevention may be unclear until release of results from two other comparative phase 3 trials with enoxaparin in 2009 and 2010.

Rivaroxaban is more likely to become clinically available soon, in light of recent results from the phase 3 RECORD4 trial demonstrating that it was significantly superior to enoxaparin 30 mg twice daily in preventing VTE following knee replacement surgery with comparable rates of major bleeding.³⁰

DISCUSSION

Question from the audience: Some surgeons in my hospital prescribe warfarin immediately after surgery without a bridge of LMWH. Is that appropriate?

Dr. Michota: Warfarin is an option for prophylaxis in orthopedic surgery, beginning on the day of surgery. It could even be started the day before surgery, but the dose should be monitored to achieve an INR between 2.0 and 3.0 within 72 hours of the procedure. If the INR is not in this optimum range, prophylactic doses of LMWH can be given until it is therapeutic.

Follow-up question: In practice, do you actually encourage INR monitoring? Usually we just put patients on a certain dose without monitoring. When we do check the INR, it’s usually 1.4 or 1.5.

Dr. Michota: Warfarin was shown to be effective in reducing VTE risk in orthopedic surgery with dose adjustment based on INR monitoring. On that basis, warfarin remains in the guideline recommendations. Unmonitored, warfarin has not been shown to reduce risk, so to give it that way would not be evidence-based.

Question from the audience: I work with several plastic surgeons who use compression stockings intraoperatively because they’ve heard of several patients who developed a PE during surgery. Is there any benefit to using compression stockings for 2 to 3 hours and then sending the patient home?

Dr. Michota: I don’t know. Theoretically, a device that is on and working before induction may reduce stasis.

The plastic surgery societies do have guidelines. Risk depends on the type of plastic surgery procedure; for example, risk probably increases due to inflammation in procedures that involve scraping the fat pads.

This is an area where we don’t have much data. These patients may be at risk, but we don’t know the best way to mitigate it. It is important that risks be discussed with patients in the informed-consent process and be documented. If the surgeon thinks it is reasonable to give pharmacologic prophylaxis after surgery, I wouldn’t hesitate to do that, but any form of bleeding in the setting of plastic surgery is catastrophic because it defeats the reason for which the surgery was done in the first place.

Question from the audience: How do the guidelines address being aggressive with pharmacologic thromboprophylaxis when a patient is already taking dual antiplatelet therapy?

Dr. Michota: For patients with an indication for VTE prophylaxis in a setting for which there is a specific strategy, the ACCP guidelines recommend that they be put on that regimen whether they are on antiplatelet agents or not. For example, consider a high-risk patient having colorectal surgery who should get unfractionated heparin or LMWH postoperatively and who is currently taking clopidogrel and aspirin. There is no evidence that the dual aspirin–clopidogrel therapy alone is effective in decreasing the risk of DVT. However, we do know that if we add on additional agents, the risk of bleeding is increased. The guidelines consider risk and benefit, and they recommend adding the agents that we know work to prevent DVT.

Question from the audience: You briefly mentioned prophylaxis for knee arthroscopy, which is the most frequently performed orthopedic procedure. Do these recommendations apply to all patients undergoing knee arthroscopy?

Dr. Michota: No. Prophylaxis is indicated only for patients with what the ACCP considers to be additional risk factors for thrombosis. They didn’t specify which risk factors, but good indications for prophylaxis would include morbid obesity, limited mobility after the procedure, a personal history of DVT, features of stasis noted on physical examination, stasis dermatitis (or other features that could indicate prior thrombosis), advanced age, and malignancy. If a patient undergoing knee arthroscopy has other nonmodifiable risk factors, you should also think about prophylaxis. But the vast majority of patients do not need it.

Question from the audience: I’m an academic hospitalist who works closely with orthopedic surgeons. Certain surgeons will only use aspirin for prophylaxis, and it is nonnegotiable. Where does that leave me from a medicolegal standpoint? Our model is to follow ACCP recommendations, but these orthopedic surgeons still use only aspirin.

Dr. Michota: You must do everything you can to come to a consensus with your surgeon colleagues. If you are uncomfortable, as a group you must say to the surgeons, “We are uncomfortable. This is how we view the data. How do you view the data?” If they answer, “We’re doing it because it’s easy, and the American Academy of Orthopaedic Surgeons says we can do it,” I don’t have a good response. But it is more likely that their use of aspirin is based on their own observations; they may not see many clots. Of course, the problem with observational data is that the numbers are not large and they are not generated in a randomized and prospective fashion. Perhaps you can come to some middle ground, but you could always make the difficult choice and say, “I’m just not going to follow your patients.”

Most surgical patients who require hospitalization should be considered at high risk for venous thromboembolism (VTE) and be given appropriate prophylaxis. For lower-risk procedures such as knee arthroscopy, prophylaxis is needed for those with individual risk factors such as morbid obesity, limited mobility after surgery, or a history of deep vein thrombosis (DVT) or malignancy. Too often, however, prophylaxis is not provided appropriately or not given at all.

This review surveys the essentials of perioperative VTE prophylaxis and important new developments in the field, which include the 2008 release of new evidence-based clinical practice guidelines on antithrombotic and thrombolytic therapy from the American College of Chest Physicians (ACCP). This 8th edition of the guidelines updates the previous edition, published in 2004, and includes a section by Geerts et al devoted to VTE prevention.¹ Other major guidelines are also discussed, as are developments in VTE-related quality measurement, management of special patient populations (those with renal impairment or morbid obesity), and emerging therapies for VTE prophylaxis.

IMPETUS FOR QUALITY IMPROVEMENT IN VTE

A new seriousness about VTE quality measures

The 8th edition of the ACCP guidelines recommends that every hospital develop a formal, active strategy to consistently identify medical and surgical patients at risk for VTE and to prevent VTE occurrence.¹ Although prior editions of the ACCP guidelines have made this recommendation for more than 2 decades, fewer than 1 in 10 acute care hospitals had any such strategy in place as recently as 5 years ago. Now, however, most US hospitals have implemented such a strategy, thanks to the growing national emphasis on health care quality measurement in recent years.

The Surgical Care Improvement Project (SCIP) has been at the forefront of this recent quality measures movement. SCIP, a joint project of the American Medical Association and federal government agencies, set a goal to reduce surgical complications in the United States by 25% from 2005 to 2010.² Two SCIP process measures relate to improving VTE prophylaxis^2,3:

• The proportion of surgical patients for whom recommended VTE prophylaxis is ordered
• The proportion of surgical patients who actually receive appropriate VTE prophylaxis within 24 hours before or after surgery.

The Joint Commission and the National Quality Forum recently endorsed these two SCIP performance measures for perioperative VTE prophylaxis along with several others relating to VTE treatment.

CMS raises the stakes with reimbursement restrictions

More significantly, the federal government’s Centers for Medicare and Medicaid Services (CMS) will soon refuse to reimburse for hospital treatment of a primary diagnosis of DVT or pulmonary embolism (PE) following recent (within 30 days) total hip or knee arthroplasty. Effective October 1, 2009, a primary VTE diagnosis following these joint replacement procedures will be added to CMS’ current list of “never events,” or hospital-acquired conditions for which CMS will not provide reimbursement because they are considered the result of preventable medical errors. (Notably, treatment of DVT or PE as a secondary diagnosis will still be reimbursed—for example, if a joint replacement patient develops nosocomial pneumonia, is transferred to the intensive care unit, and then develops VTE.) This addition of DVT and PE to the list is highly controversial since these events sometimes develop even if prophylactic therapy is appropriate and aggressive.

Strategies to promote best practices

In the update for the new 8th edition of its guidelines, the ACCP added recommendations on specific ways for hospitals to identify patients at high risk for VTE and ensure that they receive appropriate prophylaxis. These include the use of computer decision-support systems, preprinted orders, and periodic audit and feedback.¹

Researchers at Brigham and Women’s Hospital evaluated the effectiveness of a computer alert system for notifying physicians of newly hospitalized patients at risk for DVT who were not receiving prevention therapy within the first 24 hours of hospital admission.⁴ These patients presumably “fell through the cracks” and warranted prophylaxis but were otherwise not recognized by the health care team. Risk was determined by a scoring system based on multiple variables, including malignancy, previous DVT or PE, hypercoagulability, major surgery, advanced age, obesity, ordered bed rest, and treatment with hormone replacement therapy or oral contraceptives. Study physicians had to acknowledge having received the alert but could choose whether or not to order VTE prophylaxis. Prophylaxis was used in considerably more patients from the intervention group than from a control group of high-risk patients whose physicians did not receive alerts (34% vs 14%, respectively); accordingly, the risk of a symptomatic DVT or PE event at 90 days was reduced by 41% in the intervention group.

Despite this evidence of improved practice under the alert system, the study begs the question of why the percentage of patients at risk for VTE who were given prophylaxis was still so low (34%), demonstrating how much progress in improving practice remains to be achieved.

PROPHYLAXIS STRATEGIES: MATCHING THERAPY TO RISK

A fundamental consideration in determining the degree of VTE prophylaxis that a surgical patient may need is the thromboembolic risk of the procedure itself. Table 1 presents a procedure-based ranking of risk based on recommendations in the 8th edition of the ACCP guidelines.¹ As risk increases, so does the intensity of prophylaxis, with increasing reliance on pharmacologic strategies. The vast majority of patients who are hospitalized for surgery will fall into the moderate- or high-risk categories in Table 1.

A patient’s risk of thrombosis is also influenced by individual risk factors (Table 2),^1,5 many of which are nonmodifiable. A thorough preoperative evaluation is important to reveal “hidden” risk factors such as thrombo­philia and a family or personal history of VTE.

 

 

NONPHARMACOLOGIC PROPHYLAXIS STRATEGIES

Does ambulation prevent DVT?

Although it is commonly accepted that walking prevents DVT, this has never been directly tested. Walking may simply be a marker of health, and healthy people are less prone to develop thromboses. We have almost no evidence to show that forcing an unhealthy person to walk helps prevent DVT. Early ambulation offers many benefits and should be encouraged, but it should not be considered DVT prophylaxis; it is simply good hospital care.

Mechanical devices: Adherence is key

Amaragiri and Lees conducted a systematic literature review of randomized controlled trials evaluating the effectiveness of graduated compression stockings (elastic stockings) for preventing DVT in various groups of hospitalized patients.⁶ The analysis demonstrated a statistically significant reduction in DVT incidence with graduated compression stockings compared with control both among the nine trials in which stockings were used alone (odds ratio = 0.34) and among the seven trials in which stockings were used in addition to another method of thrombo­prophylaxis (odds ratio = 0.24). Although benefit was demonstrated, many of the trials in this review involved patients undergoing gynecologic surgery and date from the 1970s and 1980s (when obesity was less prevalent), so the applicability of their results today may be limited.

The 8th edition of the ACCP guidelines recommends that mechanical methods of VTE prophylaxis be used primarily in patients who are at high risk of bleeding and that careful attention be directed to ensuring their proper use and optimal adherence.¹ The latter point about adherence cannot be emphasized enough, as graduated compression stockings and other mechanical devices have been shown not to be effective unless they are worn at least 18 to 20 hours a day. This degree of adherence is difficult to achieve, as it can severely limit patient mobility and leave patients susceptible to develop­ment of pressure ulcers.

Mechanical compression should be initiated prior to induction of anesthesia and continue intraoperatively and then into the postanesthesia care unit. Orders for use of mechanical devices should include instructions in the patient’s medical chart specifying how—and for how many hours per day—they are to be worn. Not doing so leaves the physician vulnerable to litigation, especially as the ACCP guidelines include language on optimal adherence to these devices (“they should be removed for only a short time each day when the patient is actually walking or for bathing”¹).

Continuous external compression therapy

Newer mechanical device options include a continuous external compression therapy system that allows patients to be mobile while wearing it and provides rhythmic compression that results in good peak venous flows. Ideally such a device could be put on the patient preoperatively and worn during surgery, throughout the hospital stay, and even at home during recovery. Anecdotally, however, I see patients turn these new devices off at the side of the bed just as often as they do with traditional devices.

Vena caval interruption

Vena caval interruption involves placement of a retrievable vena cava filter before surgery and removal some time later; it offers the potential for VTE prophylaxis in patients who could not tolerate even minor amounts of bleeding, such as certain trauma patients. The Eastern Association for the Surgery of Trauma has put forth a consensus recommendation to consider vena caval interruption in high-risk trauma patients who cannot receive pharmacologic prophylaxis.⁷ A randomized trial evaluating the usefulness of vena caval interruption for patients undergoing surgery is needed. For now, this intervention should be regarded as experimental and considered only on a highly individualized basis.

PHARMACOLOGIC PROPHYLAXIS

The ACCP guidelines’ recommendations for pharmacologic VTE prophylaxis in surgical patients are lengthy, and many remain unchanged from prior editions, so this discussion will focus on broad principles and new recommendations adopted in the recent 8th edition.¹Table 3 lists notable new recommendations for patients undergoing specific surgical procedures.

Timing of initiation

Pharmacologic VTE prophylaxis generally should begin 8 to 24 hours postoperatively. Of course, adequate hemostasis is required before initiation, and the net risk/benefit tradeoff with regard to timing of anticoagulant initiation has still not been well studied in many surgical patient populations.

Extended prophylaxis

In the update for the 8th edition of its guidelines, the ACCP added an explicit recommendation for extended outpatient prophylaxis with low-molecular-weight heparin (LMWH) for up to 28 days postoperatively in selected high-risk patients undergoing general or gynecologic surgery, including those with cancer or a history of VTE.¹ This recommendation was based largely on studies of extended prophylaxis in patients with cancer undergoing colorectal surgery.⁸

Increased appreciation of the value of extended VTE prophylaxis after discharge is linked to a growing recognition that DVT and PE episodes in the community setting are often related to a recent hospital stay for either medical illness or surgery. A population-based study found that 59% of all community cases of a first lifetime VTE event in residents of Olmsted County, Minn., over a 15-year period could be linked to current or recent (< 30 days) hospitalization or nursing home residence.⁹ A similar population-based study in the Worcester, Mass., area found that three-fourths of all VTE events in a 3-year period occurred in the outpatient setting.¹⁰ Among patients with these outpatient VTE events, a large proportion had undergone surgery (23%) or hospitalization (37%) in the prior 3 months; among those, 67% experienced their VTE within 1 month of their time in the hospital.

These findings are no surprise, since surgery induces a hypercoagulable state that, when combined with individual risk factors such as obesity, old age, or poor heart function, cannot be assumed to return to baseline on postoperative day 4 or 5 just because the patient is being discharged.

Orthopedic surgery

For patients undergoing major orthopedic procedures, the ACCP guidelines recommend against routine screening for VTE with Doppler ultrasonography before discharge if the patient is asymptomatic.¹ Such screening is not considered cost-effective because asymptomatic clots often are found, for which treatment is uncertain, and proximal clots may be missed, giving a false sense of security.

ACCP recommendations for prophylaxis in patients undergoing orthopedic surgery are summarized in Table 4.¹ As shown, the recommended options for hip and knee replacement and hip fracture surgery are almost exclusively medication-based. The vast majority of patients undergoing these major orthopedic procedures need prophylaxis beyond their typical hospital stay of 3 or 4 days. About 90% of DVTs following knee replacement occur within 2 weeks of surgery, so 10 to 14 days of therapy is probably the best practice in this setting, although a longer period may be justified depending on the patient’s risk profile. For hip replacement, in contrast, 28 to 30 days of prophylaxis is often preferable, since about half of all DVTs in that setting occur more than 2 weeks after surgery.

New to the ACCP guidelines in the 8th edition is the recommendation that patients undergoing knee arthroscopy who have risk factors for VTE (or whose procedure is complicated) should receive 1 week of prophylaxis with LMWH.¹ Also new are recommendations for patients with risk factors undergoing single- or multilevel laminectomy (Table 4).

 

 

Recommendations unchanged in neurosurgery, spinal injury, trauma, burns

Recommendations for neurosurgery remain unchanged from the prior (2004) edition of the ACCP guidelines and are still based on the 2000 meta-analysis by Iorio and Agnelli of LMWH prophylaxis in neurosurgery cases.¹¹ In the United States, the standard is overwhelmingly to use mechanical devices for thromboprophylaxis in neurosurgery, even for patients with cancer.

For prophylaxis in surgical patients with spinal cord injury, multisystem trauma, or burns, LMWH is predominantly used, and the ACCP recommendations are unchanged from 2004.

Drug-specific considerations

LMWH vs vitamin K antagonist. Although vitamin K antagonists (warfarin) still appear in the latest ACCP recommendations,¹ LMWH is preferable. A 2004 meta-analysis of studies comparing vitamin K antagonists with LMWH for prophylaxis in patients undergoing orthopedic surgery found that vitamin K antagonists were associated with more episodes of total DVT (relative risk [RR] = 1.51; 95% CI, 1.27–1.79) and proximal DVT (RR = 1.51; 95% CI, 1.04–2.17) compared with LMWH.¹² No difference was found in rates of wound hematoma or major bleeding. This finding of inferiority for vitamin K antagonists came despite the likelihood that warfarin was more often administered correctly (ie, with dose adjustment to achieve an international normalized ratio [INR] of 2.0 to 3.0 within 72 hours after surgery) in the studies in this analysis than it is in real-world practice.

Fondaparinux. The indirect factor Xa–specific inhibitor fondaparinux has had a surprisingly limited clinical adoption despite having been widely studied and found to be safe and effective. This is likely attributable in part to its 17-hour half-life, which raises concerns that it may take 3 days for its effects to stop if a patient begins to bleed. Large phase 3 studies have found fondaparinux to be equivalent to LMWH in VTE prevention after hip replacement, marginally superior to LMWH after knee replacement, and superior to LMWH following hip fracture repair.¹³ Fondaparinux was associated with an increase in bleeding events and instances of transfusion requirement, but only in one of the studies, which was in the setting of knee replacement surgery.¹⁴

Aspirin not recommended by ACCP. Although aspirin reduces the risk of VTE, practice guidelines from both the ACCP¹ and the International Union of Angiology¹⁵ contain no recommendation for its use as prophylaxis because it is considered less effective and more risky than other therapies. In contrast, clinical practice guidelines from the American Academy of Orthopaedic Surgeons suggest that aspirin is reasonable for VTE prophylaxis.¹⁶ The varying recommendations reflect differences in perspective among these different specialties.

Aspirin has the advantages of ease of use and low cost, but it is clearly not the best evidence-based approach for VTE prophylaxis. The only recent randomized trial evidence in support of aspirin comes from the Pulmonary Embolism Prevention trial, a study with a flawed design involving more than 13,000 patients undergoing surgery for hip fracture or elective arthroplasty in five countries.¹⁷ Patients were randomized to receive aspirin 160 mg daily or placebo for 35 days along with any other prophylaxis deemed necessary (an important potential confounder). Aspirin was associated with an absolute reduction in symptomatic events of less than 1% relative to placebo, and no benefit was observed within the first week. The best results with aspirin were among patients with hip fracture. No benefit was shown among patients undergoing hip arthroplasty or knee arthroplasty; in those groups, both the aspirin and placebo recipients were also treated with LMWH. An absolute increase in rates of wound bleeding (0.6% increase) and gastrointestinal bleeding (1.0% increase) was observed in the aspirin group. The absolute increase in complications was greater than the absolute reduction in episodes of symptomatic DVT: for every episode of symptomatic DVT averted, one wound bleed and 10 gastrointestinal bleeds occurred.

SPECIAL PATIENT POPULATIONS

Renal impairment

The 8th edition of the ACCP guidelines recommends that renal function be kept in mind when considering LMWH, fondaparinux, and other antithrombotic drugs that are cleared by the kidneys. Fondaparinux and LMWH can bioaccumulate in patients with renal insufficiency, who have a higher risk of bleeding to begin with, thereby compounding the risk. Options for patients with renal compromise include avoiding drugs that bioaccumulate, using a lower dosage, and monitoring the drug level or anticoagulant effect.¹

Fondaparinux is explicitly contraindicated in patients with low body weight (< 50 kg) or renal impairment (creatinine clearance < 30 mL/min). Renal function should be assessed periodically in any patients receiving the drug.¹⁸

I also would not use fondaparinux or LMWH in patients with rapidly changing renal function. For patients with chronic, stable renal impairment, one can reduce the dose of LMWH empirically; one LMWH, enoxaparin, has specific dosing guidelines in its package insert (one-third reduction in dose), but this option does not hold for patients with rapidly changing renal function.¹⁹

Obesity

The 8th edition of the ACCP guidelines recommends weight-based dosing of thromboprophylactic agents in obese patients. The guidelines particularly recommend that patients undergoing inpatient bariatric surgery be given higher doses of LMWH or unfractionated heparin.^1,20

Frederiksen et al measured the anticoagulant effect of a single fixed dose of a LMWH (using anti-factor Xa heparin activity levels) and found that it was dependent on body weight.²¹ This suggests that fixed doses that are effective in normal-weight patients may have no detectable anti-coagulant effect in patients with very high body weight.

Weight-based dosing: mounting nonprospective evidence. Weight-based dosage adjustment for the morbidly obese has not been directly studied in a prospective, randomized fashion. A nonrandomized study by Scholten et al compared two regimens of enoxaparin (30 mg twice daily vs 40 mg twice daily) among 481 obese patients undergoing bariatric surgery; each regimen was used along with mechanical thromboprophylaxis.²² They found that the higher-dose regimen was associated with significantly fewer postoperative DVT complications (0.6% vs 5.4%; P < .01) without an increase in bleeding complications.

Separately, Shepherd et al used weight-adjusted doses of unfractionated heparin (started on the evening of surgery) to achieve subtherapeutic peak anti–factor Xa heparin activity levels of 0.11 to 0.25 IU/mL in a series of 700 patients undergoing laparoscopic gastric bypass surgery.²³ The resulting doses were greater than those in traditional fixed-rate protocols, but rates of bleeding and VTE events were low and comparable to those reported in patients receiving standard doses. 

Don’t rule out multimodal approaches. Multimodal prophylaxis can also be used in obese patients and need not be abandoned as a result of size considerations. For instance, two intermittent compression therapy devices can be pieced together with a Velcro binder if a single device is too small to be worn.

 

 

EMERGING ANTICOAGULANT OPTIONS

For many years, unfractionated heparin was the only available parenteral anticoagulant. While heparin has broad anticoagulant properties, it also has well-established limitations, including the need for parenteral delivery, recent problems related to contamination (it is derived from pig intestines), and of course heparin-induced thrombocytopenia (HIT). HIT is an immune-mediated form of platelet activation that can lead to widespread thrombosis throughout the body. It is more commonly associated with venous thrombosis, but arterial events with limb-threatening ischemia may also occur. LMWH is associated with a reduced risk of HIT, but LMWH does not avoid the risk entirely.

Beyond the issue of avoiding HIT, newer anticoagulant therapies are being developed with the aim of oral administration and more targeted inhibition of coagulation factors IIa (thrombin) and Xa.²⁴

Oral direct thrombin inhibitors

One of the two most promising classes of emerging anticoagulants is the direct thrombin inhibitors, most of which are being developed for oral administration. There were high hopes for the initial compound in this class, ximelagatran, but it was abandoned about 5 years ago because of hepatotoxicity.

Dabigatran is the direct thrombin inhibitor furthest along in development today. Currently approved in Europe for prevention of VTE in patients undergoing total hip or knee replacement surgery, dabigatran is likely to be available soon in the United States. It is administered orally, has a rapid onset of action (< 1 hour), and has a predictable anticoagulant response that requires no monitoring.²⁴ Because dabigatran is excreted essentially unchanged by the kidneys and may bioaccumulate, it should not be used in patients with renal impairment or rapidly changing renal function.

In phase 3 clinical trials for VTE prevention in knee replacement surgery, dabigatran was at least as effective as enoxaparin 40 mg once daily and had a comparable safety profile,²⁵ but it was slightly less effective than enoxaparin 30 mg twice daily.²⁶ In a phase 3 trial in patients under­going hip replacement surgery, dabigatran was equivalent in efficacy and safety to enoxaparin 40 mg once daily.²⁷

Oral direct factor Xa inhibitors

A key rationale for direct inhibition of factor Xa is that it results in inhibition of thrombin production on the activated platelet. Whereas fondaparinux is an indirect inhibitor of factor Xa, direct factor Xa inhibitors offer an advantage in that they inhibit factor Xa within the prothrombinase complex, which occurs on the surface of a platelet and is the main site for thrombin development (very little thrombin is actually produced on endothelial cells). Recall the adage that “thrombin begets more thrombin”: it activates not only platelets but the intrinsic and extrinsic pathways.²⁸

Factor Xa may be a better target than thrombin for a number of other reasons:

• Factor Xa is believed to have few functions (compared with thrombin) outside of coagulation

• In vitro studies show that factor Xa has a wider therapeutic window than thrombin, which translates to greater separation between drug levels that will confer efficacy and bleeding
• Thrombin inhibitors are associated with rebound thrombin generation (there is no evidence of this with factor Xa inhibitors)
• The efficacy of heparin-based anticoagulants improves as selectivity for factor Xa increases (unfractionated heparin is less effective than LMWH, which is less effective than fondaparinux).

Two direct factor Xa inhibitors—both administered orally—are far along in development, as detailed below.

Apixaban has shown promise, but the phase 3 ADVANCE-1 study of apixaban for VTE prevention in patients undergoing knee surgery did not meet statistical criteria for noninferiority compared with enoxaparin 30 mg twice daily.²⁹ This prompted a delay in regulatory filings for apixaban in the United States, and the drug’s prospects for approval for VTE prevention may be unclear until release of results from two other comparative phase 3 trials with enoxaparin in 2009 and 2010.

Rivaroxaban is more likely to become clinically available soon, in light of recent results from the phase 3 RECORD4 trial demonstrating that it was significantly superior to enoxaparin 30 mg twice daily in preventing VTE following knee replacement surgery with comparable rates of major bleeding.³⁰

DISCUSSION

Question from the audience: Some surgeons in my hospital prescribe warfarin immediately after surgery without a bridge of LMWH. Is that appropriate?

Dr. Michota: Warfarin is an option for prophylaxis in orthopedic surgery, beginning on the day of surgery. It could even be started the day before surgery, but the dose should be monitored to achieve an INR between 2.0 and 3.0 within 72 hours of the procedure. If the INR is not in this optimum range, prophylactic doses of LMWH can be given until it is therapeutic.

Follow-up question: In practice, do you actually encourage INR monitoring? Usually we just put patients on a certain dose without monitoring. When we do check the INR, it’s usually 1.4 or 1.5.

Dr. Michota: Warfarin was shown to be effective in reducing VTE risk in orthopedic surgery with dose adjustment based on INR monitoring. On that basis, warfarin remains in the guideline recommendations. Unmonitored, warfarin has not been shown to reduce risk, so to give it that way would not be evidence-based.

Question from the audience: I work with several plastic surgeons who use compression stockings intraoperatively because they’ve heard of several patients who developed a PE during surgery. Is there any benefit to using compression stockings for 2 to 3 hours and then sending the patient home?

Dr. Michota: I don’t know. Theoretically, a device that is on and working before induction may reduce stasis.

The plastic surgery societies do have guidelines. Risk depends on the type of plastic surgery procedure; for example, risk probably increases due to inflammation in procedures that involve scraping the fat pads.

This is an area where we don’t have much data. These patients may be at risk, but we don’t know the best way to mitigate it. It is important that risks be discussed with patients in the informed-consent process and be documented. If the surgeon thinks it is reasonable to give pharmacologic prophylaxis after surgery, I wouldn’t hesitate to do that, but any form of bleeding in the setting of plastic surgery is catastrophic because it defeats the reason for which the surgery was done in the first place.

Question from the audience: How do the guidelines address being aggressive with pharmacologic thromboprophylaxis when a patient is already taking dual antiplatelet therapy?

Dr. Michota: For patients with an indication for VTE prophylaxis in a setting for which there is a specific strategy, the ACCP guidelines recommend that they be put on that regimen whether they are on antiplatelet agents or not. For example, consider a high-risk patient having colorectal surgery who should get unfractionated heparin or LMWH postoperatively and who is currently taking clopidogrel and aspirin. There is no evidence that the dual aspirin–clopidogrel therapy alone is effective in decreasing the risk of DVT. However, we do know that if we add on additional agents, the risk of bleeding is increased. The guidelines consider risk and benefit, and they recommend adding the agents that we know work to prevent DVT.

Question from the audience: You briefly mentioned prophylaxis for knee arthroscopy, which is the most frequently performed orthopedic procedure. Do these recommendations apply to all patients undergoing knee arthroscopy?

Dr. Michota: No. Prophylaxis is indicated only for patients with what the ACCP considers to be additional risk factors for thrombosis. They didn’t specify which risk factors, but good indications for prophylaxis would include morbid obesity, limited mobility after the procedure, a personal history of DVT, features of stasis noted on physical examination, stasis dermatitis (or other features that could indicate prior thrombosis), advanced age, and malignancy. If a patient undergoing knee arthroscopy has other nonmodifiable risk factors, you should also think about prophylaxis. But the vast majority of patients do not need it.

Question from the audience: I’m an academic hospitalist who works closely with orthopedic surgeons. Certain surgeons will only use aspirin for prophylaxis, and it is nonnegotiable. Where does that leave me from a medicolegal standpoint? Our model is to follow ACCP recommendations, but these orthopedic surgeons still use only aspirin.

Dr. Michota: You must do everything you can to come to a consensus with your surgeon colleagues. If you are uncomfortable, as a group you must say to the surgeons, “We are uncomfortable. This is how we view the data. How do you view the data?” If they answer, “We’re doing it because it’s easy, and the American Academy of Orthopaedic Surgeons says we can do it,” I don’t have a good response. But it is more likely that their use of aspirin is based on their own observations; they may not see many clots. Of course, the problem with observational data is that the numbers are not large and they are not generated in a randomized and prospective fashion. Perhaps you can come to some middle ground, but you could always make the difficult choice and say, “I’m just not going to follow your patients.”

If this is a typical audience of physicians involved in perioperative care, about 35% to 40% of you have been sued for malpractice and have learned the hard way some of the lessons we will discuss today. This session will begin with an overview of malpractice law and medicolegal principles, after which we will review three real-life malpractice cases and open the floor to the audience for discussion of the lessons these cases can offer.

MALPRACTICE LAWSUITS ARE COMMON, EXPENSIVE, DAMAGING

If a physician practices long enough, lawsuits are nearly inevitable, especially in certain specialties. Surgeons and anesthesiologists are sued about once every 4 to 5 years; internists generally are sued less, averaging once every 7 to 10 years,¹ but hospitalists and others who practice a good deal of perioperative care probably constitute a higher risk pool among internists.

At the same time, it is estimated that only one in eight preventable medical errors committed in hospitals results in a malpractice claim.² From 1995 to 2000, the number of new malpractice claims actually declined by approximately 4%.³

Jury awards can be huge

Fewer than half (42%) of verdicts in malpractice cases are won by plaintiffs.⁴ But when plaintiffs succeed, the awards can be costly: the mean amount of physician malpractice payments in the United States in 2006 (the most recent data available) was $311,965, according to the National Practitioner Data Bank.⁵ Cases that involve a death result in substantially higher payments, averaging $1.4 million.⁴

Lawsuits are traumatic

Even if a physician is covered by good malpractice insurance, a malpractice lawsuit typically changes his or her life. It causes major disruption to the physician’s practice and may damage his or her reputation. Lawsuits cause considerable emotional distress, including a loss of self-esteem, particularly if the physician feels that a mistake was made in the delivery of care.

CATEGORIES OF CLAIMS IN MALPRACTICE LAW

Malpractice law involves torts, which are civil wrongs causing injury to a person or property for which the plaintiff may seek redress through the courts. In general, the plaintiff seeks financial compensation. Practitioners do not go to jail for committing malpractice unless a district attorney decides that the harm was committed intentionally, in which case criminal charges may be brought.

There are many different categories of claims in malpractice law. The most common pertaining to perioperative medicine involve issues surrounding informed consent and medical negligence (the worst form being wrongful death).

Informed consent

Although everyone is familiar with informed consent, details of the process are called into question when something goes wrong. Informed consent is based on the right of patient autonomy: each person has a right to determine what will be done to his or her body, which includes the right to consent to or refuse treatment.

For any procedure, treatment, or medication, patients should be informed about the following:

• The nature of the intervention
• The benefits of the intervention (why it is being recommended)
• Significant risks reasonably expected to exist
• Available alternatives (including “no treatment”).

If possible, it is important that the patient’s family understand the risks involved, because if the patient dies or becomes incapacitated, a family that is surprised by the outcome is more likely to sue.

The standard to which physicians are held in malpractice suits is that of a “reasonable physician” dealing with a “reasonable patient.” Often, a plaintiff claims that he or she did not know that a specific risk was involved, and the doctor claims that he or she spent a “typical” amount of time explaining all the risks. If that amount of time was only a few seconds, that may not pass the “reasonable physician” test, as a jury might conclude that more time may have been necessary.

Negligence and wrongful death

Negligence, including wrongful death, is a very common category of claim. The plaintiff generally must demonstrate four elements in negligence claims:

• The provider had a duty to the patient
• The duty was breached
• An injury occurred
• The breach of duty was a “proximate cause” of the injury.

Duty arises from the physician-patient relationship: any person whose name is on the medical chart essentially has a duty to the patient and can be brought into the case, even if the involvement was only peripheral.

Breach of duty. Determining whether a breach of duty occurred often involves a battle of medical experts. The standard of care is defined as what a reasonable practitioner would do under the same or similar circumstances, assuming similar training and background. The jury decides whether the physician met the standard of care based on testimony from experts.

The Latin phrase res ipsa loquitur means “the thing speaks for itself.” In surgery, the classic example is if an instrument or a towel were accidentally left in a patient. In such a situation, the breach of duty is obvious, so the strategy of the defense generally must be to show that the patient was not harmed by the breach.

Injury. The concept of injury can be broad and often depends on distinguishing bad practice from a bad or unfortunate outcome. For instance, a patient who suffered multisystem trauma but whose life was saved by medical intervention could sue if he ended up with paresthesia in the foot afterwards. An expert may be called to help determine whether or not the complication is reasonable for the particular medical situation. Patient expectations usually factor prominently into questions of injury.

Proximate cause often enters into situations involving wrongful death. A clear understanding of the cause of death or evidence from an autopsy is not necessarily required for a plaintiff to argue that malpractice was a proximate cause of death. A plaintiff’s attorney will often speculate why a patient died, and because the plaintiff’s burden of proof is so low (see next paragraph), it may not help the defense to argue that it is pure speculation that a particular event was related to the death. 

A low burden of proof

In a civil tort, the burden of proof is established by a “preponderance of the evidence,” meaning that the allegation is “more likely than not.” This is a much lower standard than the “beyond a reasonable doubt” threshold used for criminal proceedings. In other words, the plaintiff has to show only that the chance that malpractice occurred was greater than 50%. 

Three types of damages

Potential damages (financial compensation) in malpractice suits fall into three categories:

• Economic, or the monetary costs of an injury (eg, medical bills or loss of income)
• Noneconomic (eg, pain and suffering, loss of ability to have sex)
• Punitive, or damages to punish a defendant for willful and wanton conduct.

Punitive damages are generally not covered by malpractice insurance policies and are only rarely involved in cases against an individual physician. They are more often awarded when deep pockets are perceived to be involved, such as in a case against a hospital system or an insurance company, and when the jury wants to punish the entity for doing something that was believed to be willful.

 

 

REDUCING THE RISK OF BEING SUED

Physicians tend to get sued when a bad outcome occurs that can be associated with substandard care or poor communication. Steps can be taken to reduce the risk of being sued, which can be simplified to the “four Cs”: competence, communication, compassion, and charting (Table 1).

Regardless of the circumstances, communication is probably the most important factor determining whether a physician will be sued. Sometimes a doctor does everything right medically but gets sued because of lack of communication with the patient. Conversely, many of us know of veteran physicians who still practice medicine as they did 35 years ago but are never sued because they have a great rapport with their patients and their patients love them for it.

The importance of careful charting also cannot be overemphasized. In malpractice cases, experts for the plaintiff will comb through the medical records and be sure to notice if something is missing. The plaintiff also benefits enormously if, for instance, nurses documented that they paged the doctor many times over a 3-day period and got no response.

CASE 1: PATIENT DIES DURING PREOPERATIVE STRESS TEST FOR KNEE SURGERY

A 65-year-old man with New York Heart Association class III cardiac disease (marked limitation of physical activity) is scheduled for a total knee arthroplasty and is seen at the preoperative testing center. His past medical history includes coronary artery disease, chronic obstructive pulmonary disease, hypertension, and prior repair of an abdominal aortic aneurysm. He is referred for a preoperative stress test.

Dobutamine stress echocardiography is performed. His target heart rate is reached at 132 beats per minute with sporadic premature ventricular contractions. Toward the end of the test, he complains of shortness of breath and chest pain. The test is terminated, and the patient goes into ventricular tachycardia and then ventricular fibrillation. Despite resuscitative efforts, he dies.

Dr. Michota: From the family’s perspective, this patient had come for quality-of-life–enhancing surgery. They were looking forward to him getting a new knee so he could play golf again when he retired. The doctor convinced them that he needed a stress test first, which ends up killing him. Mr. Donnelly, as a lawyer, would you want to be the plaintiff’s attorney in this case?

Mr. Donnelly: Very much so. The family never contemplated that their loved one would die from this procedure. The first issue would be whether or not the possibility of complications or death from the stress test had been discussed with the patient or his family.

Consent must be truly ‘informed’ and documented

Dr. Michota: How many of our audience members who do preoperative assessments and refer patients for stress testing can recall a conversation with a patient that included the comment, “You may die from getting this test”? Before this case occurred, I never brought up this possibility, but I do now. This case illustrates how important expectations are.

Comment from the audience: I think you have to be careful of your own bias about risks. You might say to the patient, “There’s a risk that you’ll have an arrhythmia and die,” but if you also tell him, “I’ve never seen that happen during a stress test in my 10 years of practice,” you’ve biased the informed consent. The family can say, “Well, he basically told us that it wasn’t going to happen; he’d never seen a case of it.”

Dr. Michota: Are there certain things we shouldn’t say? Surely you should never promise somebody a good outcome by saying that certain rare events never happen.

Mr. Donnelly: That’s true. You can give percentages. You might say, “I’m letting you know there’s a possibility that you could die from this, but it’s a low percentage risk.” That way, you are informing the patient. This relates to the “reasonable physician” and “reasonable patient” standard. You are expected to do what is reasonable.

Is a signed consent form adequate defense?

Dr. Michota: What should the defense team do now? Let’s say informed consent was obtained and documented at the stress lab. The patient signed a form that listed death as a risk, but no family members were present. Is this an adequate defense?

Mr. Donnelly: It depends on whether the patient understood what was on the form and had the opportunity to ask questions.

Dr. Michota: So the form means nothing?

Mr. Donnelly: If he didn’t understand it, that is correct.

Dr. Michota: We thought he understood it. Can’t we just say, “Of course he understood it—he signed it.”

Mr. Donnelly: No. Keep in mind that most jurors have been patients at one time or another. There may be a perception that physicians are rushed or don’t have time to answer questions. Communication is really important here.

Dr. Michota: But surely there’s a physician on the jury who can help talk to the other jurors about how it really works.

Mr. Donnelly: No, a “jury of peers” is not a jury box of physicians. The plaintiff’s attorneys tend to exclude scientists and other educated professionals from the jury; they don’t want jurors who are accustomed to holding people to certain standards. They prefer young, impressionable people who wouldn’t think twice about awarding somebody $20 million.

 

 

Who should be obtaining informed consent?

Question from the audience: Who should have obtained informed consent for this patient—the doctor who referred him for the stress test or the cardiologist who conducted the test? Sometimes I have to get informed consent for specialty procedures that I myself do not understand very well. Could I be considered culpable even though I’m not the one doing the procedure? I can imagine an attorney asking, “Doctor, are you a cardiologist? How many of these tests do you do? Why are you the one doing the informed consent? Did the patient really understand the effects of the test? Do you really understand them?”

Dr. Michota: That question is even more pertinent if the patient is referred to another institution covered under different malpractice insurance. You can bet the other provider will try to blame you if something goes wrong.

Mr. Donnelly: In an ideal world, both the referring physician and the physician who does the test discuss the risks, benefits, and alternatives, and answer all questions that the patient and family have. The discussion is properly documented in the medical record.

Question from the audience: Can you address the issue of supervision? What is the liability of a resident or intern in doing the informed consent?

Mr. Donnelly: The attending physician is usually responsible for everything that a resident does. I would prefer that the attending obtain the informed consent.

Dr. Michota: But our fellows and second-year postgraduate residents are independent licensed practitioners in Ohio. Does letting them handle informed consent pose a danger to a defense team’s legal case?

Mr. Donnelly: It’s not necessarily a danger medically, but it gives the plaintiff something to talk about. They will ignore the fact that an independent licensed practitioner obtained the informed consent. They will simply focus on the fact that the physician was a resident or fellow. They will claim, “They had this young, inexperienced doctor give the informed consent when there were staff physicians with 20 years of experience who should have done it.” Plaintiffs will attempt to get a lot of mileage out of these minor issues.

Question from the audience: At our institution, the physician is present with the technician, so that when the physician obtains consent, the technician signs as a witness. The bottom of the long form basically says, “By signing this form, I attest that the physician performing the test has informed me of the benefits and risks of this test, and I agree to go ahead. I fully understand the implications of the test.” Does that have value in the eyes of the law?

Mr. Donnelly: That’s a great informed consent process and will have great value. That said, you can still get sued, because you can get sued for anything. But the jury ultimately decides, and odds are that with a process like yours they will conclude that the patient knew all the risks and benefits and alternatives because he or she signed the form and the doctor documented that everything was discussed.

Confidentiality vs family involvement

Comment from the audience: I’m struck by the comments that informed consent is supposed to be with the family so that there will be living witnesses in case the patient dies. According to Health Insurance Portability and Accountability Act (HIPAA) regulations, we have to be very careful to maintain confidentiality. For a competent patient, medical discussions are private unless specific permission has been obtained to involve the family.

Mr. Donnelly: Yes, we’ve assumed that the patient gave permission to discuss these issues with his family. If the patient does not want that, obviously you can’t include the family because of HIPAA regulations.

Question from the audience: Should we routinely ask a patient to involve the family in an informed consent in case something goes wrong?

Mr. Donnelly: No. In general, it’s appropriate only if the family is already present.

Dr. Michota: Keep in mind that there’s nothing you can do to completely prevent being sued. You can do everything right and still get sued. If you’re following good clinical practice and a patient doesn’t want to involve the family, all you can do is document your discussion and that you believed the patient understood the risks of the procedure.

Question from the audience: Do you consider a patient’s decision-making capacity for informed consent? Should physicians document it prior to obtaining consent? A plaintiff can always claim that an elderly patient did not understand.

Mr. Donnelly: I have never seen specific documentation that a patient had capacity to consent, but it’s a good idea for a borderline case. For such a case, it’s especially important to involve the family and document, “I discussed the matter with this elderly patient and her husband and three daughters.” You could also get a psychiatric consult or a social worker to help determine whether a patient has the capacity to make legal and medical decisions.

CASE 2: FATAL POSTSURGICAL MI RAISES QUESTIONS ABOUT THE PREOP EVALUATION

A 75-year-old man with rectal cancer presents for colorectal surgery. He has a remote cardiac history but exercises regularly and has a good functional classification without symptoms. The surgery is uneventful, but the patient develops hypotension in the postanesthesia care unit. He improves the next morning and goes to the colorectal surgery ward. Internal bleeding occurs but initially goes unrecognized; on postoperative day 2, his hemoglobin is found to be 2 g/dL and he is transferred to the intensive care unit, then back to the operating room, where he suffers cardiac arrest. He is revived but dies 2 weeks later. Autopsy reveals that he died of a myocardial infarction (MI).

Dr. Michota: The complaint in this case is that the patient did not receive a proper preoperative evaluation because no cardiac workup was done. As the hypothetical defense attorney, do you feel this case has merit? The patient most likely had an MI from demand ischemia due to hemorrhage, but does this have anything to do with not having a cardiac workup?

Mr. Donnelly: You as the physician are saying that even if he had an electrocardiogram (ECG), it is likely that nothing would have been determined. The cardiac problems he had prior to the surgery in question were well controlled, occurred in the distant past, and may not have affected the outcome. Maybe his remote cardiac problems were irrelevant and something else caused the MI that killed him. Nevertheless, the fact that the ECG wasn’t done still could be a major issue for the plaintiff’s attorney. After the fact, it seems like a no-brainer that an ECG should have been done in a case like this, and it’s easy for the plaintiff to argue that it might have detected something. The defense has to keep reminding the jury that the case cannot be looked at retrospectively, and that’s a tall order.

Dr. Michota: This case shows that even in the context of high-quality care, such things can happen. We have spent a lot of time at this summit talking about guidelines. But at the end of the day, if somebody dies perioperatively of an MI, the family may start looking for blame and any plaintiff’s attorney will go through the record to see if a preoperative ECG was done. If it wasn’t, a suit will get filed.

 

 

The four Cs offer the best protection

Question from the audience: Even if the physician had done the ECG, how do you know the plaintiff’s attorney wouldn’t attack him for not ordering a stress test? And if he had done a stress test, then they’d ask why he didn’t order a catheterization. Where is it going to end?

Dr. Michota: You make a good point. The best way for physicians to protect themselves is to follow the four Cs mentioned earlier: competent care, communication, compassion, and charting. After I learned about this case, the next time I was in the clinic and didn’t order an ECG, I asked the patient, “Did you expect that we would do an ECG here today?” When he responded that he did, I talked to him about how it wasn’t indicated and probably would not change management. So that level of communication can sometimes prevent a lawsuit that might stem from a patient not feeling informed. I’m not suggesting that you spend hours explaining details with each patient, but it’s good to be aware that cases like this happen and how you can reduce their likelihood.

Battles of the experts

Question from the audience: Exactly what standard is applied when the “standard of care” is determined in a court? For instance, my hospital may routinely order stress tests, whereas the American College of Cardiology and American Heart Association (ACC/AHA) guidelines are more restrictive in recommending when a stress test is indicated. Which standard would apply in court?

Dr. Michota: It’s easy to find a plaintiff’s expert who will say just about anything. If you claim that everybody gets a stress test at your community hospital and a patient dies during the stress test, the plaintiff’s team will find an expert to say, “That was an unnecessary test and posed an unnecessary risk.” If you’re in a setting where stress tests are rarely done for preoperative evaluation, they’ll find an expert to say, “Stress testing was available; it should have been done.”

This is when the battles of the experts occur. If you have a superstar physician on your defense team, the plaintiff will have to find someone of equal pedigree who can argue against him or her. Sometimes cases go away because the defense lines up amazing experts and the plaintiffs lose their stomach for the money it would take to bring the case forward. But usually cases do not involve that caliber of experts; most notables in the field are academic physicians who don’t do this type of work. Usually you get busy physicians who spend 75% of their time in clinical practice and seem smart enough to impress the jury. Although they can say things that aren’t even factual, they can sway the jury. 

Question from the audience: I would not have ordered a preoperative ECG on this healthy 75-year-old, but one of the experts at this summit said that he would get a baseline ECG for such a case. How are differences like these reconciled in the legal context?

Dr. Michota: The standard to which we are held is that of a reasonable physician. Can you show that your approach was a reasonable one? Can you say, “I didn’t order the ECG for the following reasons, and I discussed the issue with the patient”? Or alternately, “An ECG was ordered for the following reasons, and I discussed it with the patient”? The jury will want to know whether the care that was provided was reasonable.

Costs and consequences of being sued

Question from the audience: What does it cost to mount a defense in a malpractice trial?

Mr. Donnelly: You can easily spend more than $100,000 to go through a trial. Plaintiffs typically have three or four experts in various cities across the country, and you have to pay your lawyers to travel to those cities and take the depositions. And delays often occur. Cases get filed, dismissed, and refiled. A lot of the work that the lawyers did to prepare for the trial will have to be redone for a second, third, or fourth time as new dates for the trial are set. There are many unforeseen costs.

Dr. Michota: Let’s say the physician who did the preoperative evaluation in this case was not affiliated with the hospital and wasn’t involved in the surgery or any of the postoperative monitoring and management, which we see may have been questionable. This physician might get pulled into the case anyway because he didn’t order an ECG in the preoperative evaluation. Although an ECG wasn’t recommended in this case by the ACC/AHA guidelines, this doctor is looking at spending considerable time, energy, and money to defend himself. What if his attorney recommends that he settle for a nominal amount—say, $25,000—because it’s cheaper and easier? Are there repercussions for him as a physician when he pays out a settlement under his name?

Mr. Donnelly: Absolutely. He will be reported to the National Practitioner Data Bank, and when he renews his license or applies for a license to practice in another state, he must disclose that he has been sued and paid a settlement. The new consumer-targeted public reporting Web sites will also publicize this information. It is like a black mark against this doctor even though he never admitted any liability.

CASE 3: A CLEAR CASE OF NEGLIGENCE―WHO IS RESPONSIBLE

A 67-year-old man undergoes a laminectomy in the hospital. He develops shortness of breath postoperatively and is seen by the hospitalist team. He is started on full-dose weight-adjusted low-molecular-weight heparin (LMWH) for possible pulmonary embolism or acute coronary syndrome. His symptoms resolve and his workup is negative. It is a holiday weekend. The consultants sign off but do not stop the full-dose LMWH. The patient is discharged to the rehabilitation unit by the surgeon and the surgeon’s assistant, who include all the medications at discharge, including the full-dose LMWH. The patient is admitted to a subacute nursing facility, where the physiatrist transfers to the chart all the medications on which the patient was discharged.

The patient does well until postoperative day 7, when he develops urinary retention and can’t move his legs. At this point, someone finally questions why he is on the LMWH, and it is stopped. The patient undergoes emergency surgery to evacuate a huge spinal hematoma, but his neurologic function never recovers.

Dr. Michota: I think most of us would agree that there was negligence here. I bet a plaintiff’s attorney would love to have this case.

Mr. Donnelly: Absolutely. The patient can no longer walk, so it’s already a high-value case. It would be even more so if we supposed that the patient were only 45 years old and a corporate executive. That would make it a really high-value case.

Dr. Michota: What do you mean? Does a patient’s age or economic means matter to a plaintiff’s attorney?

Mr. Donnelly: Of course. For a plaintiff’s attorney, it’s always nice to have a case like this where there’s negligence, but the high-dollar cases typically involve a likable plaintiff who is a high wage earner with a good family. A plaintiff’s lawyer will take a case that may not be so strong on evidence of negligence if it’s likely that a jury will like the plaintiff and his or her family. Kids always help to sway a jury—jurors will feel sorry for them and want to help them. This case even has two surgeries, so the family’s medical bills will be especially high. It’s a great case for a plaintiff’s attorney.

Who’s at fault?

Dr. Michota: Let’s look at a few more case details. Once the various doctors involved in this case realized what happened, they got nervous and engaged in finger-pointing. The surgeons felt that the hospitalists should have stopped the LMWH. The hospitalists claimed that since they had signed off, the surgeons should have stopped it. The physiatrist said, “Who am I to decide to stop medications? I assumed that the hospital physicians checked the medications before sending the patient to the rehab facility.”

Interestingly, a hospitalist went back and made a chart entry after the second surgery. He wrote, “Late chart entry. Discussion with surgeon regarding LMWH. I told him to stop it.” Does that make him free and clear?

Mr. Donnelly: Actually, the hospitalist just shot his credibility, and now the jury is really angry. The dollar value of the case has just gone up.

Dr. Michota: Okay, suppose the hospitalist wouldn’t do something that obvious. Instead, he goes back to the chart after the fact, finds the same color pen as the entry at the time, and writes, “Patient is okay. Please stop LMWH,” and signs his name. Is there any way anyone is going to be able to figure that out?

Mr. Donnelly: All the other doctors and nurses will testify that the note was not in the chart before. The plaintiff will hire a handwriting expert and look at the different impressions on the paper, the inks, and the style of writing. Now the hospitalist has really escalated the situation and is liable for punitive damages, which will come out of his own pocket, since malpractice insurance doesn’t cover punitive damages. His license may be threatened. The jury will really be angered, and the plaintiff’s lawyer will love stoking the situation.

If this is a typical audience of physicians involved in perioperative care, about 35% to 40% of you have been sued for malpractice and have learned the hard way some of the lessons we will discuss today. This session will begin with an overview of malpractice law and medicolegal principles, after which we will review three real-life malpractice cases and open the floor to the audience for discussion of the lessons these cases can offer.

MALPRACTICE LAWSUITS ARE COMMON, EXPENSIVE, DAMAGING

If a physician practices long enough, lawsuits are nearly inevitable, especially in certain specialties. Surgeons and anesthesiologists are sued about once every 4 to 5 years; internists generally are sued less, averaging once every 7 to 10 years,¹ but hospitalists and others who practice a good deal of perioperative care probably constitute a higher risk pool among internists.

At the same time, it is estimated that only one in eight preventable medical errors committed in hospitals results in a malpractice claim.² From 1995 to 2000, the number of new malpractice claims actually declined by approximately 4%.³

Jury awards can be huge

Fewer than half (42%) of verdicts in malpractice cases are won by plaintiffs.⁴ But when plaintiffs succeed, the awards can be costly: the mean amount of physician malpractice payments in the United States in 2006 (the most recent data available) was $311,965, according to the National Practitioner Data Bank.⁵ Cases that involve a death result in substantially higher payments, averaging $1.4 million.⁴

Lawsuits are traumatic

Even if a physician is covered by good malpractice insurance, a malpractice lawsuit typically changes his or her life. It causes major disruption to the physician’s practice and may damage his or her reputation. Lawsuits cause considerable emotional distress, including a loss of self-esteem, particularly if the physician feels that a mistake was made in the delivery of care.

CATEGORIES OF CLAIMS IN MALPRACTICE LAW

Malpractice law involves torts, which are civil wrongs causing injury to a person or property for which the plaintiff may seek redress through the courts. In general, the plaintiff seeks financial compensation. Practitioners do not go to jail for committing malpractice unless a district attorney decides that the harm was committed intentionally, in which case criminal charges may be brought.

There are many different categories of claims in malpractice law. The most common pertaining to perioperative medicine involve issues surrounding informed consent and medical negligence (the worst form being wrongful death).

Informed consent

Although everyone is familiar with informed consent, details of the process are called into question when something goes wrong. Informed consent is based on the right of patient autonomy: each person has a right to determine what will be done to his or her body, which includes the right to consent to or refuse treatment.

For any procedure, treatment, or medication, patients should be informed about the following:

• The nature of the intervention
• The benefits of the intervention (why it is being recommended)
• Significant risks reasonably expected to exist
• Available alternatives (including “no treatment”).

If possible, it is important that the patient’s family understand the risks involved, because if the patient dies or becomes incapacitated, a family that is surprised by the outcome is more likely to sue.

The standard to which physicians are held in malpractice suits is that of a “reasonable physician” dealing with a “reasonable patient.” Often, a plaintiff claims that he or she did not know that a specific risk was involved, and the doctor claims that he or she spent a “typical” amount of time explaining all the risks. If that amount of time was only a few seconds, that may not pass the “reasonable physician” test, as a jury might conclude that more time may have been necessary.

Negligence and wrongful death

Negligence, including wrongful death, is a very common category of claim. The plaintiff generally must demonstrate four elements in negligence claims:

• The provider had a duty to the patient
• The duty was breached
• An injury occurred
• The breach of duty was a “proximate cause” of the injury.

Duty arises from the physician-patient relationship: any person whose name is on the medical chart essentially has a duty to the patient and can be brought into the case, even if the involvement was only peripheral.

Breach of duty. Determining whether a breach of duty occurred often involves a battle of medical experts. The standard of care is defined as what a reasonable practitioner would do under the same or similar circumstances, assuming similar training and background. The jury decides whether the physician met the standard of care based on testimony from experts.

The Latin phrase res ipsa loquitur means “the thing speaks for itself.” In surgery, the classic example is if an instrument or a towel were accidentally left in a patient. In such a situation, the breach of duty is obvious, so the strategy of the defense generally must be to show that the patient was not harmed by the breach.

Injury. The concept of injury can be broad and often depends on distinguishing bad practice from a bad or unfortunate outcome. For instance, a patient who suffered multisystem trauma but whose life was saved by medical intervention could sue if he ended up with paresthesia in the foot afterwards. An expert may be called to help determine whether or not the complication is reasonable for the particular medical situation. Patient expectations usually factor prominently into questions of injury.

Proximate cause often enters into situations involving wrongful death. A clear understanding of the cause of death or evidence from an autopsy is not necessarily required for a plaintiff to argue that malpractice was a proximate cause of death. A plaintiff’s attorney will often speculate why a patient died, and because the plaintiff’s burden of proof is so low (see next paragraph), it may not help the defense to argue that it is pure speculation that a particular event was related to the death. 

A low burden of proof

In a civil tort, the burden of proof is established by a “preponderance of the evidence,” meaning that the allegation is “more likely than not.” This is a much lower standard than the “beyond a reasonable doubt” threshold used for criminal proceedings. In other words, the plaintiff has to show only that the chance that malpractice occurred was greater than 50%. 

Three types of damages

Potential damages (financial compensation) in malpractice suits fall into three categories:

• Economic, or the monetary costs of an injury (eg, medical bills or loss of income)
• Noneconomic (eg, pain and suffering, loss of ability to have sex)
• Punitive, or damages to punish a defendant for willful and wanton conduct.

Punitive damages are generally not covered by malpractice insurance policies and are only rarely involved in cases against an individual physician. They are more often awarded when deep pockets are perceived to be involved, such as in a case against a hospital system or an insurance company, and when the jury wants to punish the entity for doing something that was believed to be willful.

 

 

REDUCING THE RISK OF BEING SUED

Physicians tend to get sued when a bad outcome occurs that can be associated with substandard care or poor communication. Steps can be taken to reduce the risk of being sued, which can be simplified to the “four Cs”: competence, communication, compassion, and charting (Table 1).

Regardless of the circumstances, communication is probably the most important factor determining whether a physician will be sued. Sometimes a doctor does everything right medically but gets sued because of lack of communication with the patient. Conversely, many of us know of veteran physicians who still practice medicine as they did 35 years ago but are never sued because they have a great rapport with their patients and their patients love them for it.

The importance of careful charting also cannot be overemphasized. In malpractice cases, experts for the plaintiff will comb through the medical records and be sure to notice if something is missing. The plaintiff also benefits enormously if, for instance, nurses documented that they paged the doctor many times over a 3-day period and got no response.

CASE 1: PATIENT DIES DURING PREOPERATIVE STRESS TEST FOR KNEE SURGERY

A 65-year-old man with New York Heart Association class III cardiac disease (marked limitation of physical activity) is scheduled for a total knee arthroplasty and is seen at the preoperative testing center. His past medical history includes coronary artery disease, chronic obstructive pulmonary disease, hypertension, and prior repair of an abdominal aortic aneurysm. He is referred for a preoperative stress test.

Dobutamine stress echocardiography is performed. His target heart rate is reached at 132 beats per minute with sporadic premature ventricular contractions. Toward the end of the test, he complains of shortness of breath and chest pain. The test is terminated, and the patient goes into ventricular tachycardia and then ventricular fibrillation. Despite resuscitative efforts, he dies.

Dr. Michota: From the family’s perspective, this patient had come for quality-of-life–enhancing surgery. They were looking forward to him getting a new knee so he could play golf again when he retired. The doctor convinced them that he needed a stress test first, which ends up killing him. Mr. Donnelly, as a lawyer, would you want to be the plaintiff’s attorney in this case?

Mr. Donnelly: Very much so. The family never contemplated that their loved one would die from this procedure. The first issue would be whether or not the possibility of complications or death from the stress test had been discussed with the patient or his family.

Consent must be truly ‘informed’ and documented

Dr. Michota: How many of our audience members who do preoperative assessments and refer patients for stress testing can recall a conversation with a patient that included the comment, “You may die from getting this test”? Before this case occurred, I never brought up this possibility, but I do now. This case illustrates how important expectations are.

Comment from the audience: I think you have to be careful of your own bias about risks. You might say to the patient, “There’s a risk that you’ll have an arrhythmia and die,” but if you also tell him, “I’ve never seen that happen during a stress test in my 10 years of practice,” you’ve biased the informed consent. The family can say, “Well, he basically told us that it wasn’t going to happen; he’d never seen a case of it.”

Dr. Michota: Are there certain things we shouldn’t say? Surely you should never promise somebody a good outcome by saying that certain rare events never happen.

Mr. Donnelly: That’s true. You can give percentages. You might say, “I’m letting you know there’s a possibility that you could die from this, but it’s a low percentage risk.” That way, you are informing the patient. This relates to the “reasonable physician” and “reasonable patient” standard. You are expected to do what is reasonable.

Is a signed consent form adequate defense?

Dr. Michota: What should the defense team do now? Let’s say informed consent was obtained and documented at the stress lab. The patient signed a form that listed death as a risk, but no family members were present. Is this an adequate defense?

Mr. Donnelly: It depends on whether the patient understood what was on the form and had the opportunity to ask questions.

Dr. Michota: So the form means nothing?

Mr. Donnelly: If he didn’t understand it, that is correct.

Dr. Michota: We thought he understood it. Can’t we just say, “Of course he understood it—he signed it.”

Mr. Donnelly: No. Keep in mind that most jurors have been patients at one time or another. There may be a perception that physicians are rushed or don’t have time to answer questions. Communication is really important here.

Dr. Michota: But surely there’s a physician on the jury who can help talk to the other jurors about how it really works.

Mr. Donnelly: No, a “jury of peers” is not a jury box of physicians. The plaintiff’s attorneys tend to exclude scientists and other educated professionals from the jury; they don’t want jurors who are accustomed to holding people to certain standards. They prefer young, impressionable people who wouldn’t think twice about awarding somebody $20 million.

 

 

Who should be obtaining informed consent?

Question from the audience: Who should have obtained informed consent for this patient—the doctor who referred him for the stress test or the cardiologist who conducted the test? Sometimes I have to get informed consent for specialty procedures that I myself do not understand very well. Could I be considered culpable even though I’m not the one doing the procedure? I can imagine an attorney asking, “Doctor, are you a cardiologist? How many of these tests do you do? Why are you the one doing the informed consent? Did the patient really understand the effects of the test? Do you really understand them?”

Dr. Michota: That question is even more pertinent if the patient is referred to another institution covered under different malpractice insurance. You can bet the other provider will try to blame you if something goes wrong.

Mr. Donnelly: In an ideal world, both the referring physician and the physician who does the test discuss the risks, benefits, and alternatives, and answer all questions that the patient and family have. The discussion is properly documented in the medical record.

Question from the audience: Can you address the issue of supervision? What is the liability of a resident or intern in doing the informed consent?

Mr. Donnelly: The attending physician is usually responsible for everything that a resident does. I would prefer that the attending obtain the informed consent.

Dr. Michota: But our fellows and second-year postgraduate residents are independent licensed practitioners in Ohio. Does letting them handle informed consent pose a danger to a defense team’s legal case?

Mr. Donnelly: It’s not necessarily a danger medically, but it gives the plaintiff something to talk about. They will ignore the fact that an independent licensed practitioner obtained the informed consent. They will simply focus on the fact that the physician was a resident or fellow. They will claim, “They had this young, inexperienced doctor give the informed consent when there were staff physicians with 20 years of experience who should have done it.” Plaintiffs will attempt to get a lot of mileage out of these minor issues.

Question from the audience: At our institution, the physician is present with the technician, so that when the physician obtains consent, the technician signs as a witness. The bottom of the long form basically says, “By signing this form, I attest that the physician performing the test has informed me of the benefits and risks of this test, and I agree to go ahead. I fully understand the implications of the test.” Does that have value in the eyes of the law?

Mr. Donnelly: That’s a great informed consent process and will have great value. That said, you can still get sued, because you can get sued for anything. But the jury ultimately decides, and odds are that with a process like yours they will conclude that the patient knew all the risks and benefits and alternatives because he or she signed the form and the doctor documented that everything was discussed.

Confidentiality vs family involvement

Comment from the audience: I’m struck by the comments that informed consent is supposed to be with the family so that there will be living witnesses in case the patient dies. According to Health Insurance Portability and Accountability Act (HIPAA) regulations, we have to be very careful to maintain confidentiality. For a competent patient, medical discussions are private unless specific permission has been obtained to involve the family.

Mr. Donnelly: Yes, we’ve assumed that the patient gave permission to discuss these issues with his family. If the patient does not want that, obviously you can’t include the family because of HIPAA regulations.

Question from the audience: Should we routinely ask a patient to involve the family in an informed consent in case something goes wrong?

Mr. Donnelly: No. In general, it’s appropriate only if the family is already present.

Dr. Michota: Keep in mind that there’s nothing you can do to completely prevent being sued. You can do everything right and still get sued. If you’re following good clinical practice and a patient doesn’t want to involve the family, all you can do is document your discussion and that you believed the patient understood the risks of the procedure.

Question from the audience: Do you consider a patient’s decision-making capacity for informed consent? Should physicians document it prior to obtaining consent? A plaintiff can always claim that an elderly patient did not understand.

Mr. Donnelly: I have never seen specific documentation that a patient had capacity to consent, but it’s a good idea for a borderline case. For such a case, it’s especially important to involve the family and document, “I discussed the matter with this elderly patient and her husband and three daughters.” You could also get a psychiatric consult or a social worker to help determine whether a patient has the capacity to make legal and medical decisions.

CASE 2: FATAL POSTSURGICAL MI RAISES QUESTIONS ABOUT THE PREOP EVALUATION

A 75-year-old man with rectal cancer presents for colorectal surgery. He has a remote cardiac history but exercises regularly and has a good functional classification without symptoms. The surgery is uneventful, but the patient develops hypotension in the postanesthesia care unit. He improves the next morning and goes to the colorectal surgery ward. Internal bleeding occurs but initially goes unrecognized; on postoperative day 2, his hemoglobin is found to be 2 g/dL and he is transferred to the intensive care unit, then back to the operating room, where he suffers cardiac arrest. He is revived but dies 2 weeks later. Autopsy reveals that he died of a myocardial infarction (MI).

Dr. Michota: The complaint in this case is that the patient did not receive a proper preoperative evaluation because no cardiac workup was done. As the hypothetical defense attorney, do you feel this case has merit? The patient most likely had an MI from demand ischemia due to hemorrhage, but does this have anything to do with not having a cardiac workup?

Mr. Donnelly: You as the physician are saying that even if he had an electrocardiogram (ECG), it is likely that nothing would have been determined. The cardiac problems he had prior to the surgery in question were well controlled, occurred in the distant past, and may not have affected the outcome. Maybe his remote cardiac problems were irrelevant and something else caused the MI that killed him. Nevertheless, the fact that the ECG wasn’t done still could be a major issue for the plaintiff’s attorney. After the fact, it seems like a no-brainer that an ECG should have been done in a case like this, and it’s easy for the plaintiff to argue that it might have detected something. The defense has to keep reminding the jury that the case cannot be looked at retrospectively, and that’s a tall order.

Dr. Michota: This case shows that even in the context of high-quality care, such things can happen. We have spent a lot of time at this summit talking about guidelines. But at the end of the day, if somebody dies perioperatively of an MI, the family may start looking for blame and any plaintiff’s attorney will go through the record to see if a preoperative ECG was done. If it wasn’t, a suit will get filed.

 

 

The four Cs offer the best protection

Question from the audience: Even if the physician had done the ECG, how do you know the plaintiff’s attorney wouldn’t attack him for not ordering a stress test? And if he had done a stress test, then they’d ask why he didn’t order a catheterization. Where is it going to end?

Dr. Michota: You make a good point. The best way for physicians to protect themselves is to follow the four Cs mentioned earlier: competent care, communication, compassion, and charting. After I learned about this case, the next time I was in the clinic and didn’t order an ECG, I asked the patient, “Did you expect that we would do an ECG here today?” When he responded that he did, I talked to him about how it wasn’t indicated and probably would not change management. So that level of communication can sometimes prevent a lawsuit that might stem from a patient not feeling informed. I’m not suggesting that you spend hours explaining details with each patient, but it’s good to be aware that cases like this happen and how you can reduce their likelihood.

Battles of the experts

Question from the audience: Exactly what standard is applied when the “standard of care” is determined in a court? For instance, my hospital may routinely order stress tests, whereas the American College of Cardiology and American Heart Association (ACC/AHA) guidelines are more restrictive in recommending when a stress test is indicated. Which standard would apply in court?

Dr. Michota: It’s easy to find a plaintiff’s expert who will say just about anything. If you claim that everybody gets a stress test at your community hospital and a patient dies during the stress test, the plaintiff’s team will find an expert to say, “That was an unnecessary test and posed an unnecessary risk.” If you’re in a setting where stress tests are rarely done for preoperative evaluation, they’ll find an expert to say, “Stress testing was available; it should have been done.”

This is when the battles of the experts occur. If you have a superstar physician on your defense team, the plaintiff will have to find someone of equal pedigree who can argue against him or her. Sometimes cases go away because the defense lines up amazing experts and the plaintiffs lose their stomach for the money it would take to bring the case forward. But usually cases do not involve that caliber of experts; most notables in the field are academic physicians who don’t do this type of work. Usually you get busy physicians who spend 75% of their time in clinical practice and seem smart enough to impress the jury. Although they can say things that aren’t even factual, they can sway the jury. 

Question from the audience: I would not have ordered a preoperative ECG on this healthy 75-year-old, but one of the experts at this summit said that he would get a baseline ECG for such a case. How are differences like these reconciled in the legal context?

Dr. Michota: The standard to which we are held is that of a reasonable physician. Can you show that your approach was a reasonable one? Can you say, “I didn’t order the ECG for the following reasons, and I discussed the issue with the patient”? Or alternately, “An ECG was ordered for the following reasons, and I discussed it with the patient”? The jury will want to know whether the care that was provided was reasonable.

Costs and consequences of being sued

Question from the audience: What does it cost to mount a defense in a malpractice trial?

Mr. Donnelly: You can easily spend more than $100,000 to go through a trial. Plaintiffs typically have three or four experts in various cities across the country, and you have to pay your lawyers to travel to those cities and take the depositions. And delays often occur. Cases get filed, dismissed, and refiled. A lot of the work that the lawyers did to prepare for the trial will have to be redone for a second, third, or fourth time as new dates for the trial are set. There are many unforeseen costs.

Dr. Michota: Let’s say the physician who did the preoperative evaluation in this case was not affiliated with the hospital and wasn’t involved in the surgery or any of the postoperative monitoring and management, which we see may have been questionable. This physician might get pulled into the case anyway because he didn’t order an ECG in the preoperative evaluation. Although an ECG wasn’t recommended in this case by the ACC/AHA guidelines, this doctor is looking at spending considerable time, energy, and money to defend himself. What if his attorney recommends that he settle for a nominal amount—say, $25,000—because it’s cheaper and easier? Are there repercussions for him as a physician when he pays out a settlement under his name?

Mr. Donnelly: Absolutely. He will be reported to the National Practitioner Data Bank, and when he renews his license or applies for a license to practice in another state, he must disclose that he has been sued and paid a settlement. The new consumer-targeted public reporting Web sites will also publicize this information. It is like a black mark against this doctor even though he never admitted any liability.

CASE 3: A CLEAR CASE OF NEGLIGENCE―WHO IS RESPONSIBLE

A 67-year-old man undergoes a laminectomy in the hospital. He develops shortness of breath postoperatively and is seen by the hospitalist team. He is started on full-dose weight-adjusted low-molecular-weight heparin (LMWH) for possible pulmonary embolism or acute coronary syndrome. His symptoms resolve and his workup is negative. It is a holiday weekend. The consultants sign off but do not stop the full-dose LMWH. The patient is discharged to the rehabilitation unit by the surgeon and the surgeon’s assistant, who include all the medications at discharge, including the full-dose LMWH. The patient is admitted to a subacute nursing facility, where the physiatrist transfers to the chart all the medications on which the patient was discharged.

The patient does well until postoperative day 7, when he develops urinary retention and can’t move his legs. At this point, someone finally questions why he is on the LMWH, and it is stopped. The patient undergoes emergency surgery to evacuate a huge spinal hematoma, but his neurologic function never recovers.

Dr. Michota: I think most of us would agree that there was negligence here. I bet a plaintiff’s attorney would love to have this case.

Mr. Donnelly: Absolutely. The patient can no longer walk, so it’s already a high-value case. It would be even more so if we supposed that the patient were only 45 years old and a corporate executive. That would make it a really high-value case.

Dr. Michota: What do you mean? Does a patient’s age or economic means matter to a plaintiff’s attorney?

Mr. Donnelly: Of course. For a plaintiff’s attorney, it’s always nice to have a case like this where there’s negligence, but the high-dollar cases typically involve a likable plaintiff who is a high wage earner with a good family. A plaintiff’s lawyer will take a case that may not be so strong on evidence of negligence if it’s likely that a jury will like the plaintiff and his or her family. Kids always help to sway a jury—jurors will feel sorry for them and want to help them. This case even has two surgeries, so the family’s medical bills will be especially high. It’s a great case for a plaintiff’s attorney.

Who’s at fault?

Dr. Michota: Let’s look at a few more case details. Once the various doctors involved in this case realized what happened, they got nervous and engaged in finger-pointing. The surgeons felt that the hospitalists should have stopped the LMWH. The hospitalists claimed that since they had signed off, the surgeons should have stopped it. The physiatrist said, “Who am I to decide to stop medications? I assumed that the hospital physicians checked the medications before sending the patient to the rehab facility.”

Interestingly, a hospitalist went back and made a chart entry after the second surgery. He wrote, “Late chart entry. Discussion with surgeon regarding LMWH. I told him to stop it.” Does that make him free and clear?

Mr. Donnelly: Actually, the hospitalist just shot his credibility, and now the jury is really angry. The dollar value of the case has just gone up.

Dr. Michota: Okay, suppose the hospitalist wouldn’t do something that obvious. Instead, he goes back to the chart after the fact, finds the same color pen as the entry at the time, and writes, “Patient is okay. Please stop LMWH,” and signs his name. Is there any way anyone is going to be able to figure that out?

Mr. Donnelly: All the other doctors and nurses will testify that the note was not in the chart before. The plaintiff will hire a handwriting expert and look at the different impressions on the paper, the inks, and the style of writing. Now the hospitalist has really escalated the situation and is liable for punitive damages, which will come out of his own pocket, since malpractice insurance doesn’t cover punitive damages. His license may be threatened. The jury will really be angered, and the plaintiff’s lawyer will love stoking the situation.

If this is a typical audience of physicians involved in perioperative care, about 35% to 40% of you have been sued for malpractice and have learned the hard way some of the lessons we will discuss today. This session will begin with an overview of malpractice law and medicolegal principles, after which we will review three real-life malpractice cases and open the floor to the audience for discussion of the lessons these cases can offer.

MALPRACTICE LAWSUITS ARE COMMON, EXPENSIVE, DAMAGING

If a physician practices long enough, lawsuits are nearly inevitable, especially in certain specialties. Surgeons and anesthesiologists are sued about once every 4 to 5 years; internists generally are sued less, averaging once every 7 to 10 years,¹ but hospitalists and others who practice a good deal of perioperative care probably constitute a higher risk pool among internists.

At the same time, it is estimated that only one in eight preventable medical errors committed in hospitals results in a malpractice claim.² From 1995 to 2000, the number of new malpractice claims actually declined by approximately 4%.³

Jury awards can be huge

Fewer than half (42%) of verdicts in malpractice cases are won by plaintiffs.⁴ But when plaintiffs succeed, the awards can be costly: the mean amount of physician malpractice payments in the United States in 2006 (the most recent data available) was $311,965, according to the National Practitioner Data Bank.⁵ Cases that involve a death result in substantially higher payments, averaging $1.4 million.⁴

Lawsuits are traumatic

Even if a physician is covered by good malpractice insurance, a malpractice lawsuit typically changes his or her life. It causes major disruption to the physician’s practice and may damage his or her reputation. Lawsuits cause considerable emotional distress, including a loss of self-esteem, particularly if the physician feels that a mistake was made in the delivery of care.

CATEGORIES OF CLAIMS IN MALPRACTICE LAW

Malpractice law involves torts, which are civil wrongs causing injury to a person or property for which the plaintiff may seek redress through the courts. In general, the plaintiff seeks financial compensation. Practitioners do not go to jail for committing malpractice unless a district attorney decides that the harm was committed intentionally, in which case criminal charges may be brought.

There are many different categories of claims in malpractice law. The most common pertaining to perioperative medicine involve issues surrounding informed consent and medical negligence (the worst form being wrongful death).

Informed consent

Although everyone is familiar with informed consent, details of the process are called into question when something goes wrong. Informed consent is based on the right of patient autonomy: each person has a right to determine what will be done to his or her body, which includes the right to consent to or refuse treatment.

For any procedure, treatment, or medication, patients should be informed about the following:

• The nature of the intervention
• The benefits of the intervention (why it is being recommended)
• Significant risks reasonably expected to exist
• Available alternatives (including “no treatment”).

If possible, it is important that the patient’s family understand the risks involved, because if the patient dies or becomes incapacitated, a family that is surprised by the outcome is more likely to sue.

The standard to which physicians are held in malpractice suits is that of a “reasonable physician” dealing with a “reasonable patient.” Often, a plaintiff claims that he or she did not know that a specific risk was involved, and the doctor claims that he or she spent a “typical” amount of time explaining all the risks. If that amount of time was only a few seconds, that may not pass the “reasonable physician” test, as a jury might conclude that more time may have been necessary.

Negligence and wrongful death

Negligence, including wrongful death, is a very common category of claim. The plaintiff generally must demonstrate four elements in negligence claims:

• The provider had a duty to the patient
• The duty was breached
• An injury occurred
• The breach of duty was a “proximate cause” of the injury.

Duty arises from the physician-patient relationship: any person whose name is on the medical chart essentially has a duty to the patient and can be brought into the case, even if the involvement was only peripheral.

Breach of duty. Determining whether a breach of duty occurred often involves a battle of medical experts. The standard of care is defined as what a reasonable practitioner would do under the same or similar circumstances, assuming similar training and background. The jury decides whether the physician met the standard of care based on testimony from experts.

The Latin phrase res ipsa loquitur means “the thing speaks for itself.” In surgery, the classic example is if an instrument or a towel were accidentally left in a patient. In such a situation, the breach of duty is obvious, so the strategy of the defense generally must be to show that the patient was not harmed by the breach.

Injury. The concept of injury can be broad and often depends on distinguishing bad practice from a bad or unfortunate outcome. For instance, a patient who suffered multisystem trauma but whose life was saved by medical intervention could sue if he ended up with paresthesia in the foot afterwards. An expert may be called to help determine whether or not the complication is reasonable for the particular medical situation. Patient expectations usually factor prominently into questions of injury.

Proximate cause often enters into situations involving wrongful death. A clear understanding of the cause of death or evidence from an autopsy is not necessarily required for a plaintiff to argue that malpractice was a proximate cause of death. A plaintiff’s attorney will often speculate why a patient died, and because the plaintiff’s burden of proof is so low (see next paragraph), it may not help the defense to argue that it is pure speculation that a particular event was related to the death. 

A low burden of proof

In a civil tort, the burden of proof is established by a “preponderance of the evidence,” meaning that the allegation is “more likely than not.” This is a much lower standard than the “beyond a reasonable doubt” threshold used for criminal proceedings. In other words, the plaintiff has to show only that the chance that malpractice occurred was greater than 50%. 

Three types of damages

Potential damages (financial compensation) in malpractice suits fall into three categories:

• Economic, or the monetary costs of an injury (eg, medical bills or loss of income)
• Noneconomic (eg, pain and suffering, loss of ability to have sex)
• Punitive, or damages to punish a defendant for willful and wanton conduct.

Punitive damages are generally not covered by malpractice insurance policies and are only rarely involved in cases against an individual physician. They are more often awarded when deep pockets are perceived to be involved, such as in a case against a hospital system or an insurance company, and when the jury wants to punish the entity for doing something that was believed to be willful.

 

 

REDUCING THE RISK OF BEING SUED

Physicians tend to get sued when a bad outcome occurs that can be associated with substandard care or poor communication. Steps can be taken to reduce the risk of being sued, which can be simplified to the “four Cs”: competence, communication, compassion, and charting (Table 1).

Regardless of the circumstances, communication is probably the most important factor determining whether a physician will be sued. Sometimes a doctor does everything right medically but gets sued because of lack of communication with the patient. Conversely, many of us know of veteran physicians who still practice medicine as they did 35 years ago but are never sued because they have a great rapport with their patients and their patients love them for it.

The importance of careful charting also cannot be overemphasized. In malpractice cases, experts for the plaintiff will comb through the medical records and be sure to notice if something is missing. The plaintiff also benefits enormously if, for instance, nurses documented that they paged the doctor many times over a 3-day period and got no response.

CASE 1: PATIENT DIES DURING PREOPERATIVE STRESS TEST FOR KNEE SURGERY

A 65-year-old man with New York Heart Association class III cardiac disease (marked limitation of physical activity) is scheduled for a total knee arthroplasty and is seen at the preoperative testing center. His past medical history includes coronary artery disease, chronic obstructive pulmonary disease, hypertension, and prior repair of an abdominal aortic aneurysm. He is referred for a preoperative stress test.

Dobutamine stress echocardiography is performed. His target heart rate is reached at 132 beats per minute with sporadic premature ventricular contractions. Toward the end of the test, he complains of shortness of breath and chest pain. The test is terminated, and the patient goes into ventricular tachycardia and then ventricular fibrillation. Despite resuscitative efforts, he dies.

Dr. Michota: From the family’s perspective, this patient had come for quality-of-life–enhancing surgery. They were looking forward to him getting a new knee so he could play golf again when he retired. The doctor convinced them that he needed a stress test first, which ends up killing him. Mr. Donnelly, as a lawyer, would you want to be the plaintiff’s attorney in this case?

Mr. Donnelly: Very much so. The family never contemplated that their loved one would die from this procedure. The first issue would be whether or not the possibility of complications or death from the stress test had been discussed with the patient or his family.

Consent must be truly ‘informed’ and documented

Dr. Michota: How many of our audience members who do preoperative assessments and refer patients for stress testing can recall a conversation with a patient that included the comment, “You may die from getting this test”? Before this case occurred, I never brought up this possibility, but I do now. This case illustrates how important expectations are.

Comment from the audience: I think you have to be careful of your own bias about risks. You might say to the patient, “There’s a risk that you’ll have an arrhythmia and die,” but if you also tell him, “I’ve never seen that happen during a stress test in my 10 years of practice,” you’ve biased the informed consent. The family can say, “Well, he basically told us that it wasn’t going to happen; he’d never seen a case of it.”

Dr. Michota: Are there certain things we shouldn’t say? Surely you should never promise somebody a good outcome by saying that certain rare events never happen.

Mr. Donnelly: That’s true. You can give percentages. You might say, “I’m letting you know there’s a possibility that you could die from this, but it’s a low percentage risk.” That way, you are informing the patient. This relates to the “reasonable physician” and “reasonable patient” standard. You are expected to do what is reasonable.

Is a signed consent form adequate defense?

Dr. Michota: What should the defense team do now? Let’s say informed consent was obtained and documented at the stress lab. The patient signed a form that listed death as a risk, but no family members were present. Is this an adequate defense?

Mr. Donnelly: It depends on whether the patient understood what was on the form and had the opportunity to ask questions.

Dr. Michota: So the form means nothing?

Mr. Donnelly: If he didn’t understand it, that is correct.

Dr. Michota: We thought he understood it. Can’t we just say, “Of course he understood it—he signed it.”

Mr. Donnelly: No. Keep in mind that most jurors have been patients at one time or another. There may be a perception that physicians are rushed or don’t have time to answer questions. Communication is really important here.

Dr. Michota: But surely there’s a physician on the jury who can help talk to the other jurors about how it really works.

Mr. Donnelly: No, a “jury of peers” is not a jury box of physicians. The plaintiff’s attorneys tend to exclude scientists and other educated professionals from the jury; they don’t want jurors who are accustomed to holding people to certain standards. They prefer young, impressionable people who wouldn’t think twice about awarding somebody $20 million.

 

 

Who should be obtaining informed consent?

Question from the audience: Who should have obtained informed consent for this patient—the doctor who referred him for the stress test or the cardiologist who conducted the test? Sometimes I have to get informed consent for specialty procedures that I myself do not understand very well. Could I be considered culpable even though I’m not the one doing the procedure? I can imagine an attorney asking, “Doctor, are you a cardiologist? How many of these tests do you do? Why are you the one doing the informed consent? Did the patient really understand the effects of the test? Do you really understand them?”

Dr. Michota: That question is even more pertinent if the patient is referred to another institution covered under different malpractice insurance. You can bet the other provider will try to blame you if something goes wrong.

Mr. Donnelly: In an ideal world, both the referring physician and the physician who does the test discuss the risks, benefits, and alternatives, and answer all questions that the patient and family have. The discussion is properly documented in the medical record.

Question from the audience: Can you address the issue of supervision? What is the liability of a resident or intern in doing the informed consent?

Mr. Donnelly: The attending physician is usually responsible for everything that a resident does. I would prefer that the attending obtain the informed consent.

Dr. Michota: But our fellows and second-year postgraduate residents are independent licensed practitioners in Ohio. Does letting them handle informed consent pose a danger to a defense team’s legal case?

Mr. Donnelly: It’s not necessarily a danger medically, but it gives the plaintiff something to talk about. They will ignore the fact that an independent licensed practitioner obtained the informed consent. They will simply focus on the fact that the physician was a resident or fellow. They will claim, “They had this young, inexperienced doctor give the informed consent when there were staff physicians with 20 years of experience who should have done it.” Plaintiffs will attempt to get a lot of mileage out of these minor issues.

Question from the audience: At our institution, the physician is present with the technician, so that when the physician obtains consent, the technician signs as a witness. The bottom of the long form basically says, “By signing this form, I attest that the physician performing the test has informed me of the benefits and risks of this test, and I agree to go ahead. I fully understand the implications of the test.” Does that have value in the eyes of the law?

Mr. Donnelly: That’s a great informed consent process and will have great value. That said, you can still get sued, because you can get sued for anything. But the jury ultimately decides, and odds are that with a process like yours they will conclude that the patient knew all the risks and benefits and alternatives because he or she signed the form and the doctor documented that everything was discussed.

Confidentiality vs family involvement

Comment from the audience: I’m struck by the comments that informed consent is supposed to be with the family so that there will be living witnesses in case the patient dies. According to Health Insurance Portability and Accountability Act (HIPAA) regulations, we have to be very careful to maintain confidentiality. For a competent patient, medical discussions are private unless specific permission has been obtained to involve the family.

Mr. Donnelly: Yes, we’ve assumed that the patient gave permission to discuss these issues with his family. If the patient does not want that, obviously you can’t include the family because of HIPAA regulations.

Question from the audience: Should we routinely ask a patient to involve the family in an informed consent in case something goes wrong?

Mr. Donnelly: No. In general, it’s appropriate only if the family is already present.

Dr. Michota: Keep in mind that there’s nothing you can do to completely prevent being sued. You can do everything right and still get sued. If you’re following good clinical practice and a patient doesn’t want to involve the family, all you can do is document your discussion and that you believed the patient understood the risks of the procedure.

Question from the audience: Do you consider a patient’s decision-making capacity for informed consent? Should physicians document it prior to obtaining consent? A plaintiff can always claim that an elderly patient did not understand.

Mr. Donnelly: I have never seen specific documentation that a patient had capacity to consent, but it’s a good idea for a borderline case. For such a case, it’s especially important to involve the family and document, “I discussed the matter with this elderly patient and her husband and three daughters.” You could also get a psychiatric consult or a social worker to help determine whether a patient has the capacity to make legal and medical decisions.

CASE 2: FATAL POSTSURGICAL MI RAISES QUESTIONS ABOUT THE PREOP EVALUATION

A 75-year-old man with rectal cancer presents for colorectal surgery. He has a remote cardiac history but exercises regularly and has a good functional classification without symptoms. The surgery is uneventful, but the patient develops hypotension in the postanesthesia care unit. He improves the next morning and goes to the colorectal surgery ward. Internal bleeding occurs but initially goes unrecognized; on postoperative day 2, his hemoglobin is found to be 2 g/dL and he is transferred to the intensive care unit, then back to the operating room, where he suffers cardiac arrest. He is revived but dies 2 weeks later. Autopsy reveals that he died of a myocardial infarction (MI).

Dr. Michota: The complaint in this case is that the patient did not receive a proper preoperative evaluation because no cardiac workup was done. As the hypothetical defense attorney, do you feel this case has merit? The patient most likely had an MI from demand ischemia due to hemorrhage, but does this have anything to do with not having a cardiac workup?

Mr. Donnelly: You as the physician are saying that even if he had an electrocardiogram (ECG), it is likely that nothing would have been determined. The cardiac problems he had prior to the surgery in question were well controlled, occurred in the distant past, and may not have affected the outcome. Maybe his remote cardiac problems were irrelevant and something else caused the MI that killed him. Nevertheless, the fact that the ECG wasn’t done still could be a major issue for the plaintiff’s attorney. After the fact, it seems like a no-brainer that an ECG should have been done in a case like this, and it’s easy for the plaintiff to argue that it might have detected something. The defense has to keep reminding the jury that the case cannot be looked at retrospectively, and that’s a tall order.

Dr. Michota: This case shows that even in the context of high-quality care, such things can happen. We have spent a lot of time at this summit talking about guidelines. But at the end of the day, if somebody dies perioperatively of an MI, the family may start looking for blame and any plaintiff’s attorney will go through the record to see if a preoperative ECG was done. If it wasn’t, a suit will get filed.

 

 

The four Cs offer the best protection

Question from the audience: Even if the physician had done the ECG, how do you know the plaintiff’s attorney wouldn’t attack him for not ordering a stress test? And if he had done a stress test, then they’d ask why he didn’t order a catheterization. Where is it going to end?

Dr. Michota: You make a good point. The best way for physicians to protect themselves is to follow the four Cs mentioned earlier: competent care, communication, compassion, and charting. After I learned about this case, the next time I was in the clinic and didn’t order an ECG, I asked the patient, “Did you expect that we would do an ECG here today?” When he responded that he did, I talked to him about how it wasn’t indicated and probably would not change management. So that level of communication can sometimes prevent a lawsuit that might stem from a patient not feeling informed. I’m not suggesting that you spend hours explaining details with each patient, but it’s good to be aware that cases like this happen and how you can reduce their likelihood.

Battles of the experts

Question from the audience: Exactly what standard is applied when the “standard of care” is determined in a court? For instance, my hospital may routinely order stress tests, whereas the American College of Cardiology and American Heart Association (ACC/AHA) guidelines are more restrictive in recommending when a stress test is indicated. Which standard would apply in court?

Dr. Michota: It’s easy to find a plaintiff’s expert who will say just about anything. If you claim that everybody gets a stress test at your community hospital and a patient dies during the stress test, the plaintiff’s team will find an expert to say, “That was an unnecessary test and posed an unnecessary risk.” If you’re in a setting where stress tests are rarely done for preoperative evaluation, they’ll find an expert to say, “Stress testing was available; it should have been done.”

This is when the battles of the experts occur. If you have a superstar physician on your defense team, the plaintiff will have to find someone of equal pedigree who can argue against him or her. Sometimes cases go away because the defense lines up amazing experts and the plaintiffs lose their stomach for the money it would take to bring the case forward. But usually cases do not involve that caliber of experts; most notables in the field are academic physicians who don’t do this type of work. Usually you get busy physicians who spend 75% of their time in clinical practice and seem smart enough to impress the jury. Although they can say things that aren’t even factual, they can sway the jury. 

Question from the audience: I would not have ordered a preoperative ECG on this healthy 75-year-old, but one of the experts at this summit said that he would get a baseline ECG for such a case. How are differences like these reconciled in the legal context?

Dr. Michota: The standard to which we are held is that of a reasonable physician. Can you show that your approach was a reasonable one? Can you say, “I didn’t order the ECG for the following reasons, and I discussed the issue with the patient”? Or alternately, “An ECG was ordered for the following reasons, and I discussed it with the patient”? The jury will want to know whether the care that was provided was reasonable.

Costs and consequences of being sued

Question from the audience: What does it cost to mount a defense in a malpractice trial?

Mr. Donnelly: You can easily spend more than $100,000 to go through a trial. Plaintiffs typically have three or four experts in various cities across the country, and you have to pay your lawyers to travel to those cities and take the depositions. And delays often occur. Cases get filed, dismissed, and refiled. A lot of the work that the lawyers did to prepare for the trial will have to be redone for a second, third, or fourth time as new dates for the trial are set. There are many unforeseen costs.

Dr. Michota: Let’s say the physician who did the preoperative evaluation in this case was not affiliated with the hospital and wasn’t involved in the surgery or any of the postoperative monitoring and management, which we see may have been questionable. This physician might get pulled into the case anyway because he didn’t order an ECG in the preoperative evaluation. Although an ECG wasn’t recommended in this case by the ACC/AHA guidelines, this doctor is looking at spending considerable time, energy, and money to defend himself. What if his attorney recommends that he settle for a nominal amount—say, $25,000—because it’s cheaper and easier? Are there repercussions for him as a physician when he pays out a settlement under his name?

Mr. Donnelly: Absolutely. He will be reported to the National Practitioner Data Bank, and when he renews his license or applies for a license to practice in another state, he must disclose that he has been sued and paid a settlement. The new consumer-targeted public reporting Web sites will also publicize this information. It is like a black mark against this doctor even though he never admitted any liability.

CASE 3: A CLEAR CASE OF NEGLIGENCE―WHO IS RESPONSIBLE

A 67-year-old man undergoes a laminectomy in the hospital. He develops shortness of breath postoperatively and is seen by the hospitalist team. He is started on full-dose weight-adjusted low-molecular-weight heparin (LMWH) for possible pulmonary embolism or acute coronary syndrome. His symptoms resolve and his workup is negative. It is a holiday weekend. The consultants sign off but do not stop the full-dose LMWH. The patient is discharged to the rehabilitation unit by the surgeon and the surgeon’s assistant, who include all the medications at discharge, including the full-dose LMWH. The patient is admitted to a subacute nursing facility, where the physiatrist transfers to the chart all the medications on which the patient was discharged.

The patient does well until postoperative day 7, when he develops urinary retention and can’t move his legs. At this point, someone finally questions why he is on the LMWH, and it is stopped. The patient undergoes emergency surgery to evacuate a huge spinal hematoma, but his neurologic function never recovers.

Dr. Michota: I think most of us would agree that there was negligence here. I bet a plaintiff’s attorney would love to have this case.

Mr. Donnelly: Absolutely. The patient can no longer walk, so it’s already a high-value case. It would be even more so if we supposed that the patient were only 45 years old and a corporate executive. That would make it a really high-value case.

Dr. Michota: What do you mean? Does a patient’s age or economic means matter to a plaintiff’s attorney?

Mr. Donnelly: Of course. For a plaintiff’s attorney, it’s always nice to have a case like this where there’s negligence, but the high-dollar cases typically involve a likable plaintiff who is a high wage earner with a good family. A plaintiff’s lawyer will take a case that may not be so strong on evidence of negligence if it’s likely that a jury will like the plaintiff and his or her family. Kids always help to sway a jury—jurors will feel sorry for them and want to help them. This case even has two surgeries, so the family’s medical bills will be especially high. It’s a great case for a plaintiff’s attorney.

Who’s at fault?

Dr. Michota: Let’s look at a few more case details. Once the various doctors involved in this case realized what happened, they got nervous and engaged in finger-pointing. The surgeons felt that the hospitalists should have stopped the LMWH. The hospitalists claimed that since they had signed off, the surgeons should have stopped it. The physiatrist said, “Who am I to decide to stop medications? I assumed that the hospital physicians checked the medications before sending the patient to the rehab facility.”

Interestingly, a hospitalist went back and made a chart entry after the second surgery. He wrote, “Late chart entry. Discussion with surgeon regarding LMWH. I told him to stop it.” Does that make him free and clear?

Mr. Donnelly: Actually, the hospitalist just shot his credibility, and now the jury is really angry. The dollar value of the case has just gone up.

Dr. Michota: Okay, suppose the hospitalist wouldn’t do something that obvious. Instead, he goes back to the chart after the fact, finds the same color pen as the entry at the time, and writes, “Patient is okay. Please stop LMWH,” and signs his name. Is there any way anyone is going to be able to figure that out?

Mr. Donnelly: All the other doctors and nurses will testify that the note was not in the chart before. The plaintiff will hire a handwriting expert and look at the different impressions on the paper, the inks, and the style of writing. Now the hospitalist has really escalated the situation and is liable for punitive damages, which will come out of his own pocket, since malpractice insurance doesn’t cover punitive damages. His license may be threatened. The jury will really be angered, and the plaintiff’s lawyer will love stoking the situation.