Emergency Medicine

A 59-year-old woman with a history of chronic kidney disease and atonic bladder was brought to the hospital by emergency medical services. She had fallen in her home 2 days earlier and remained on the floor until neighbors eventually heard her cries and called 911. She complained of abdominal pain and distention along with emesis.

On presentation, she had tachycardia and tachypnea. The examination was notable for pronounced abdominal distention, diminished bowel sounds, and costovertebral angle tenderness.

While laboratory work was being done, the patient’s tachypnea progressed to respiratory distress, and she ultimately required intubation. Vasopressors were started, as the patient was hemodynamically unstable. A Foley catheter was placed, which yielded about 1,100 mL of purulent urine.

Laboratory workup showed:

• Procalcitonin 189 ng/mL (reference range < 2.0 ng/mL)  
• White blood cell count 10.7 × 10⁹/L (4.5–10.0)
• Myoglobin 20,000 ng/mL (< 71)
• Serum creatinine 4.8 mg/dL (0.06–1.10).

Urinalysis was positive for infection; blood and urine cultures later were positive for Escherichia coli.

The patient went into shock that was refractory to pressors, culminating in cardiac arrest despite resuscitative measures.

EMPHYSEMATOUS CYSTITIS, A FORM OF URINARY TRACT INFECTION

Emphysematous cystitis is a rare form of complicated urinary tract infection characterized by gas inside the bladder and in the bladder wall. While the exact mechanisms underlying gas formation are not clear, gas-producing pathogens are clearly implicated in severe infection. E coli and Klebsiella pneumoniae are the most common organisms associated with emphysematous cystitis; others include Proteus mirabilis, and Enterobacter and Streptococcus species.^1,2

More than 50% of patients with emphysematous cystitis have diabetes mellitus. Other risk factors include bladder outlet obstruction, neurogenic bladder, and female sex.³ The severity of disease ranges from asymptomatic pneumaturia (up to 7% of cases)² to fulminant emphysematous cystitis, as in our patient.

The clinical presentation of emphysematous cystitis is nonspecific and can range from minimally symptomatic urinary tract infection to acute abdomen and septic shock.⁴

Some patients present with pneumaturia (the passing of gas through the urethra with micturition). Pneumaturia arises from 3 discrete causes: urologic instrumentation, fistula between the bladder and large or small bowel, and gas-producing bacteria in the bladder (emphysematous cystitis).⁵ Pneumaturia should always raise the suspicion of emphysematous cystitis.

The diagnosis can be made with either radiographic or computed tomographic evidence of gas within the bladder and bladder wall, in the absence of both bladder fistula and history of iatrogenic pneumaturia. Emphysematous cystitis should prompt urine and blood cultures to direct antimicrobial therapy, as 50% of patients with emphysematous cystitis have concomitant bacteremia.⁶

Our patient had an elevated serum level of procalcitonin, a marker of bacterial infection. Procalcitonin is a more specific biomarker of bacterial infection than acute-phase reactants such as the erythrocyte sedimentation rate or the C-reactive protein level. Measuring procalcitonin may help physicians make the diagnosis earlier, differentiate infectious from sterile causes of severe systemic inflammation, assess the severity of systemic inflammation caused by bacterial infections, and decide whether to start or discontinue antibiotic therapy.⁷

Most cases of emphysematous cystitis can be treated with antibiotics, though early diagnosis is crucial to a favorable outcome. Delay in diagnosis may contribute to the 20% mortality rate associated with this condition.⁶    

A 59-year-old woman with a history of chronic kidney disease and atonic bladder was brought to the hospital by emergency medical services. She had fallen in her home 2 days earlier and remained on the floor until neighbors eventually heard her cries and called 911. She complained of abdominal pain and distention along with emesis.

On presentation, she had tachycardia and tachypnea. The examination was notable for pronounced abdominal distention, diminished bowel sounds, and costovertebral angle tenderness.

While laboratory work was being done, the patient’s tachypnea progressed to respiratory distress, and she ultimately required intubation. Vasopressors were started, as the patient was hemodynamically unstable. A Foley catheter was placed, which yielded about 1,100 mL of purulent urine.

Laboratory workup showed:

• Procalcitonin 189 ng/mL (reference range < 2.0 ng/mL)  
• White blood cell count 10.7 × 10⁹/L (4.5–10.0)
• Myoglobin 20,000 ng/mL (< 71)
• Serum creatinine 4.8 mg/dL (0.06–1.10).

Urinalysis was positive for infection; blood and urine cultures later were positive for Escherichia coli.

The patient went into shock that was refractory to pressors, culminating in cardiac arrest despite resuscitative measures.

EMPHYSEMATOUS CYSTITIS, A FORM OF URINARY TRACT INFECTION

Emphysematous cystitis is a rare form of complicated urinary tract infection characterized by gas inside the bladder and in the bladder wall. While the exact mechanisms underlying gas formation are not clear, gas-producing pathogens are clearly implicated in severe infection. E coli and Klebsiella pneumoniae are the most common organisms associated with emphysematous cystitis; others include Proteus mirabilis, and Enterobacter and Streptococcus species.^1,2

More than 50% of patients with emphysematous cystitis have diabetes mellitus. Other risk factors include bladder outlet obstruction, neurogenic bladder, and female sex.³ The severity of disease ranges from asymptomatic pneumaturia (up to 7% of cases)² to fulminant emphysematous cystitis, as in our patient.

The clinical presentation of emphysematous cystitis is nonspecific and can range from minimally symptomatic urinary tract infection to acute abdomen and septic shock.⁴

Some patients present with pneumaturia (the passing of gas through the urethra with micturition). Pneumaturia arises from 3 discrete causes: urologic instrumentation, fistula between the bladder and large or small bowel, and gas-producing bacteria in the bladder (emphysematous cystitis).⁵ Pneumaturia should always raise the suspicion of emphysematous cystitis.

The diagnosis can be made with either radiographic or computed tomographic evidence of gas within the bladder and bladder wall, in the absence of both bladder fistula and history of iatrogenic pneumaturia. Emphysematous cystitis should prompt urine and blood cultures to direct antimicrobial therapy, as 50% of patients with emphysematous cystitis have concomitant bacteremia.⁶

Our patient had an elevated serum level of procalcitonin, a marker of bacterial infection. Procalcitonin is a more specific biomarker of bacterial infection than acute-phase reactants such as the erythrocyte sedimentation rate or the C-reactive protein level. Measuring procalcitonin may help physicians make the diagnosis earlier, differentiate infectious from sterile causes of severe systemic inflammation, assess the severity of systemic inflammation caused by bacterial infections, and decide whether to start or discontinue antibiotic therapy.⁷

Most cases of emphysematous cystitis can be treated with antibiotics, though early diagnosis is crucial to a favorable outcome. Delay in diagnosis may contribute to the 20% mortality rate associated with this condition.⁶    

A 59-year-old woman with a history of chronic kidney disease and atonic bladder was brought to the hospital by emergency medical services. She had fallen in her home 2 days earlier and remained on the floor until neighbors eventually heard her cries and called 911. She complained of abdominal pain and distention along with emesis.

On presentation, she had tachycardia and tachypnea. The examination was notable for pronounced abdominal distention, diminished bowel sounds, and costovertebral angle tenderness.

While laboratory work was being done, the patient’s tachypnea progressed to respiratory distress, and she ultimately required intubation. Vasopressors were started, as the patient was hemodynamically unstable. A Foley catheter was placed, which yielded about 1,100 mL of purulent urine.

Laboratory workup showed:

• Procalcitonin 189 ng/mL (reference range < 2.0 ng/mL)  
• White blood cell count 10.7 × 10⁹/L (4.5–10.0)
• Myoglobin 20,000 ng/mL (< 71)
• Serum creatinine 4.8 mg/dL (0.06–1.10).

Urinalysis was positive for infection; blood and urine cultures later were positive for Escherichia coli.

The patient went into shock that was refractory to pressors, culminating in cardiac arrest despite resuscitative measures.

EMPHYSEMATOUS CYSTITIS, A FORM OF URINARY TRACT INFECTION

Emphysematous cystitis is a rare form of complicated urinary tract infection characterized by gas inside the bladder and in the bladder wall. While the exact mechanisms underlying gas formation are not clear, gas-producing pathogens are clearly implicated in severe infection. E coli and Klebsiella pneumoniae are the most common organisms associated with emphysematous cystitis; others include Proteus mirabilis, and Enterobacter and Streptococcus species.^1,2

More than 50% of patients with emphysematous cystitis have diabetes mellitus. Other risk factors include bladder outlet obstruction, neurogenic bladder, and female sex.³ The severity of disease ranges from asymptomatic pneumaturia (up to 7% of cases)² to fulminant emphysematous cystitis, as in our patient.

The clinical presentation of emphysematous cystitis is nonspecific and can range from minimally symptomatic urinary tract infection to acute abdomen and septic shock.⁴

Some patients present with pneumaturia (the passing of gas through the urethra with micturition). Pneumaturia arises from 3 discrete causes: urologic instrumentation, fistula between the bladder and large or small bowel, and gas-producing bacteria in the bladder (emphysematous cystitis).⁵ Pneumaturia should always raise the suspicion of emphysematous cystitis.

The diagnosis can be made with either radiographic or computed tomographic evidence of gas within the bladder and bladder wall, in the absence of both bladder fistula and history of iatrogenic pneumaturia. Emphysematous cystitis should prompt urine and blood cultures to direct antimicrobial therapy, as 50% of patients with emphysematous cystitis have concomitant bacteremia.⁶

Our patient had an elevated serum level of procalcitonin, a marker of bacterial infection. Procalcitonin is a more specific biomarker of bacterial infection than acute-phase reactants such as the erythrocyte sedimentation rate or the C-reactive protein level. Measuring procalcitonin may help physicians make the diagnosis earlier, differentiate infectious from sterile causes of severe systemic inflammation, assess the severity of systemic inflammation caused by bacterial infections, and decide whether to start or discontinue antibiotic therapy.⁷

Most cases of emphysematous cystitis can be treated with antibiotics, though early diagnosis is crucial to a favorable outcome. Delay in diagnosis may contribute to the 20% mortality rate associated with this condition.⁶    

PHOENIX – An initiative designed to reduce avoidable emergency room visits and hospitalizations cut admissions by 16%, according to a report from a large, independent, community-based oncology practice.

The program saved nearly $3.2 million in Medicare costs over the course of the year, said Molly Mendenhall, RN, of Oncology Hematology Care in Cincinnati.

“By keeping those patients out of the hospital, we were able to improve patient quality of life, and increase patient satisfaction by treating them in their home clinic instead of the hospital,” Ms. Mendenhall said at a symposium on quality care sponsored by the American Society of Clinical Oncology.

The campaign was developed in anticipation of participating in the Oncology Care Model (OCM), a program focused on providing coordinated and high-quality care for Medicare oncology patients at the same or lower cost.

Prior to participating in OCM, Ms. Mendenhall and her colleagues set up an after-hours phone triage system, proactive chemotherapy follow-up calls, and a Saturday-Sunday urgent care clinic designed to help avoid any unnecessary hospitalizations over the weekend.

They also set up a 2-hour structured OCM treatment planning visit to prioritize shared decision making between the patient and the clinical team regarding diagnosis, symptom management, financial assistance, and other aspects of care.

The most influential part of the initiative, according to Ms. Mendenhall, was a patient-directed “Call Us Early – Call Us First” campaign that included symptom management teaching sheets, a 34-page teaching book, and branded buttons, pens, and magnets all designed to emphasize the patient responsibility to use the phone.

“All of those previous steps really wouldn’t make a difference if the patients still weren’t calling us,” Ms. Mendenhall explained.

Over the first year of participation in the OCM program, the oncology practice saw a 16% statistically significant reduction in hospital admissions (P = .005). The number of inpatient admissions per 100 patients dropped from 26.8 at baseline to 22.6 at the most recent follow-up in a report published simultaneously in the Journal of Oncology Practice.

Reduced admissions translated into a drop of $798,000 in inpatient costs per quarter over 1,600 patients, or $3.129 million in savings for the Centers for Medicare & Medicaid Services over the first year of participation in OCM, according to the researchers.

Patient satisfaction scores trended positively over the course of that year based on a review of blinded surveys that asked patients to rate clinical care, communication, access, information exchange, and other aspects of their experience.

Scores on those surveys were 8.03 on a scale of 0-10 (low to high) during the baseline period of January to September 2016, the researchers said. Scores were 8.29 and 8.26 for two follow-up surveys.

Ms. Mendenhall had no disclosures to report. Coauthors on the study provided disclosures related to Janssen Oncology, Pfizer, Amgen, Abbvie, Merck, Pharmacyclics, Bristol-Myers Squibb, Celgene, Genentech/Roche, AZTherapies, and Lilly. Two coauthors reported leadership, stock, or other ownership interests in Oncology Hematology Care/US Oncology.

SOURCE: Mendenhall M et al. Quality Care Symposium, Abstract 30.

PHOENIX – An initiative designed to reduce avoidable emergency room visits and hospitalizations cut admissions by 16%, according to a report from a large, independent, community-based oncology practice.

The program saved nearly $3.2 million in Medicare costs over the course of the year, said Molly Mendenhall, RN, of Oncology Hematology Care in Cincinnati.

“By keeping those patients out of the hospital, we were able to improve patient quality of life, and increase patient satisfaction by treating them in their home clinic instead of the hospital,” Ms. Mendenhall said at a symposium on quality care sponsored by the American Society of Clinical Oncology.

The campaign was developed in anticipation of participating in the Oncology Care Model (OCM), a program focused on providing coordinated and high-quality care for Medicare oncology patients at the same or lower cost.

Prior to participating in OCM, Ms. Mendenhall and her colleagues set up an after-hours phone triage system, proactive chemotherapy follow-up calls, and a Saturday-Sunday urgent care clinic designed to help avoid any unnecessary hospitalizations over the weekend.

They also set up a 2-hour structured OCM treatment planning visit to prioritize shared decision making between the patient and the clinical team regarding diagnosis, symptom management, financial assistance, and other aspects of care.

The most influential part of the initiative, according to Ms. Mendenhall, was a patient-directed “Call Us Early – Call Us First” campaign that included symptom management teaching sheets, a 34-page teaching book, and branded buttons, pens, and magnets all designed to emphasize the patient responsibility to use the phone.

“All of those previous steps really wouldn’t make a difference if the patients still weren’t calling us,” Ms. Mendenhall explained.

Over the first year of participation in the OCM program, the oncology practice saw a 16% statistically significant reduction in hospital admissions (P = .005). The number of inpatient admissions per 100 patients dropped from 26.8 at baseline to 22.6 at the most recent follow-up in a report published simultaneously in the Journal of Oncology Practice.

Reduced admissions translated into a drop of $798,000 in inpatient costs per quarter over 1,600 patients, or $3.129 million in savings for the Centers for Medicare & Medicaid Services over the first year of participation in OCM, according to the researchers.

Patient satisfaction scores trended positively over the course of that year based on a review of blinded surveys that asked patients to rate clinical care, communication, access, information exchange, and other aspects of their experience.

Scores on those surveys were 8.03 on a scale of 0-10 (low to high) during the baseline period of January to September 2016, the researchers said. Scores were 8.29 and 8.26 for two follow-up surveys.

Ms. Mendenhall had no disclosures to report. Coauthors on the study provided disclosures related to Janssen Oncology, Pfizer, Amgen, Abbvie, Merck, Pharmacyclics, Bristol-Myers Squibb, Celgene, Genentech/Roche, AZTherapies, and Lilly. Two coauthors reported leadership, stock, or other ownership interests in Oncology Hematology Care/US Oncology.

SOURCE: Mendenhall M et al. Quality Care Symposium, Abstract 30.

PHOENIX – An initiative designed to reduce avoidable emergency room visits and hospitalizations cut admissions by 16%, according to a report from a large, independent, community-based oncology practice.

The program saved nearly $3.2 million in Medicare costs over the course of the year, said Molly Mendenhall, RN, of Oncology Hematology Care in Cincinnati.

“By keeping those patients out of the hospital, we were able to improve patient quality of life, and increase patient satisfaction by treating them in their home clinic instead of the hospital,” Ms. Mendenhall said at a symposium on quality care sponsored by the American Society of Clinical Oncology.

The campaign was developed in anticipation of participating in the Oncology Care Model (OCM), a program focused on providing coordinated and high-quality care for Medicare oncology patients at the same or lower cost.

Prior to participating in OCM, Ms. Mendenhall and her colleagues set up an after-hours phone triage system, proactive chemotherapy follow-up calls, and a Saturday-Sunday urgent care clinic designed to help avoid any unnecessary hospitalizations over the weekend.

They also set up a 2-hour structured OCM treatment planning visit to prioritize shared decision making between the patient and the clinical team regarding diagnosis, symptom management, financial assistance, and other aspects of care.

The most influential part of the initiative, according to Ms. Mendenhall, was a patient-directed “Call Us Early – Call Us First” campaign that included symptom management teaching sheets, a 34-page teaching book, and branded buttons, pens, and magnets all designed to emphasize the patient responsibility to use the phone.

“All of those previous steps really wouldn’t make a difference if the patients still weren’t calling us,” Ms. Mendenhall explained.

Over the first year of participation in the OCM program, the oncology practice saw a 16% statistically significant reduction in hospital admissions (P = .005). The number of inpatient admissions per 100 patients dropped from 26.8 at baseline to 22.6 at the most recent follow-up in a report published simultaneously in the Journal of Oncology Practice.

Reduced admissions translated into a drop of $798,000 in inpatient costs per quarter over 1,600 patients, or $3.129 million in savings for the Centers for Medicare & Medicaid Services over the first year of participation in OCM, according to the researchers.

Patient satisfaction scores trended positively over the course of that year based on a review of blinded surveys that asked patients to rate clinical care, communication, access, information exchange, and other aspects of their experience.

Scores on those surveys were 8.03 on a scale of 0-10 (low to high) during the baseline period of January to September 2016, the researchers said. Scores were 8.29 and 8.26 for two follow-up surveys.

Ms. Mendenhall had no disclosures to report. Coauthors on the study provided disclosures related to Janssen Oncology, Pfizer, Amgen, Abbvie, Merck, Pharmacyclics, Bristol-Myers Squibb, Celgene, Genentech/Roche, AZTherapies, and Lilly. Two coauthors reported leadership, stock, or other ownership interests in Oncology Hematology Care/US Oncology.

SOURCE: Mendenhall M et al. Quality Care Symposium, Abstract 30.

Study Overview

Objective. To assess the safety and effectiveness of the use of epinephrine in out-of-hospital cardiac arrest patients.

Design. Randomized, double-blind placebo-controlled trial in the United Kingdom.

Setting and participants. Patients aged 16 years or older who had sustained an out-of-hospital cardiac arrest for which advanced life support was provided by trial-trained paramedics were eligible for inclusion. Exclusion criteria included apparent pregnancy, arrest from anaphylaxis or asthma, or the administration of epinephrine before the arrival of the trial-trained paramedic. In 1 of the 5 ambulance services, traumatic cardiac arrests were also excluded in accordance with local protocol.

Main outcome measures. The primary outcome was the rate of survival at 30 days. Secondary outcomes included rate of survival until hospital admission, length of stay in the hospital and intensive care unit (ICU), rates of survival at hospital discharge and at 3 months, and neurologic outcomes at hospital discharge and at 3 months.

Main results. Between December 2014 and October 2017, 10,623 patients were screened for eligibility in 5 National Health Service ambulance services in the United Kingdom. Of these, 8103 were eligible, and 8014 patients were assigned to either the epinephrine group (4015 patients) or the placebo group (3999 patients).

For the primary outcome, 130 patients (3.2%) in the epinephrine group were alive at 30 days in comparison to 94 patients (2.4%) in the placebo group (unadjusted odds ratio [OR] for survival, 1.39; 95% confidence interval [CI], 1.06-1.82; P = 0.02). The number needed to treat for a 30-day survival was 112 patients (95% CI, 63-500).

For the secondary outcomes, the epinephrine group had a higher survival until hospital admission: 947 patients (23.8%) as compared to 319 (8.0%) patients in the placebo group (unadjusted OR, 3.59). Otherwise, there were no difference between the 2 groups in the hospital and ICU LOS. There also was not a significant difference between the epinephrine group and the placebo group in the proportion of patients who survived until hospital discharge: 87 of 4007 patients (2.2%) in the epinephrine group and 74 of 3994 patients (1.9%) in the placebo group, with an unadjusted OR of 1.18 (95% CI, 0.85-1.61). Patients in the epinephrine group had a higher rate of severe neurologic impairment at discharge: 39 of 126 patients (31.0%) versus 16 of 90 patients (17.8%).

Conclusion. Among adults with out-of-hospital cardiac arrest, the use of epinephrine resulted in a higher rate of 30-day survival as compared with the use of placebo; however, there was no difference in the rate of a favorable neurologic outcome as more survivors in the epinephrine group had severe neurologic impairment.

Commentary

Epinephrine has been used as part of the resuscitation of patients with cardiac arrest since the 1960s. Epinephrine increases vasomotor tone during circulatory collapse, shunts more blood to the heart, and increases the likelihood of restoring spontaneous circulation.¹ However, epinephrine also decreases microvascular blood flow and can result in long-term organ dysfunction or hypoperfusion of the heart and brain.² The current study, the PARAMEDIC2 trial, by Perkins and colleagues is the largest randomized controlled trial to date to address the question of patient-centered benefit of the use of epinephrine during out-of-hospital cardiac arrest.

Similar to prior studies, patients who received epinephrine had a higher rate of 30-day survival than those who received placebo. However, there was no clear improvement in functional recovery among patients who survived, and the proportion of survivors with severe neurologic impairment was higher in the epinephrine group as compared to the placebo group. These results demonstrate that despite its ability to restore spontaneous circulation after out-of-hospital cardiac arrest, epinephrine produced only a small absolute increase in survival with worse functional recovery as compared with placebo.

One major limitation of this study is that the protocol did not control for or measure in-hospital treatments. In a prior study, the most common cause of in-hospital death was iatrogenic limitation of life support, which may result in the death of potentially viable patients.³ Another limitation of the study was the timing to administration of epinephrine. In the current study, paramedics administered the trial agent within a median of 21 minutes after the emergency call, which is a longer duration than previous out-of-hospital trials.⁴ In addition, this time to administration is much longer than that of in-hospital cardiac arrest, where epinephrine is administered a median of 3 minutes after resuscitation starts.⁵ Therefore, the results from this study cannot be extrapolated to patients with in-hospital cardiac arrest.

Applications for Clinical Practice

The current study by Perkins et al demonstrated the powerful effect of epinephrine in restoring spontaneous circulation after out-of-hospital cardiac arrest. However, epinephrine produced only a small absolute increase in survival with worse functional recovery, as compared to placebo. While further studies regarding dosage of epinephrine as well as administration based on the basis of cardiac rhythm are needed, we should question our tradition of using epinephrine in out-of-hospital cardiac arrest if meaningful neurological function is our priority.

—Ka Ming Gordon Ngai, MD, MPH, FACEP

Study Overview

Objective. To assess the safety and effectiveness of the use of epinephrine in out-of-hospital cardiac arrest patients.

Design. Randomized, double-blind placebo-controlled trial in the United Kingdom.

Setting and participants. Patients aged 16 years or older who had sustained an out-of-hospital cardiac arrest for which advanced life support was provided by trial-trained paramedics were eligible for inclusion. Exclusion criteria included apparent pregnancy, arrest from anaphylaxis or asthma, or the administration of epinephrine before the arrival of the trial-trained paramedic. In 1 of the 5 ambulance services, traumatic cardiac arrests were also excluded in accordance with local protocol.

Main outcome measures. The primary outcome was the rate of survival at 30 days. Secondary outcomes included rate of survival until hospital admission, length of stay in the hospital and intensive care unit (ICU), rates of survival at hospital discharge and at 3 months, and neurologic outcomes at hospital discharge and at 3 months.

Main results. Between December 2014 and October 2017, 10,623 patients were screened for eligibility in 5 National Health Service ambulance services in the United Kingdom. Of these, 8103 were eligible, and 8014 patients were assigned to either the epinephrine group (4015 patients) or the placebo group (3999 patients).

For the primary outcome, 130 patients (3.2%) in the epinephrine group were alive at 30 days in comparison to 94 patients (2.4%) in the placebo group (unadjusted odds ratio [OR] for survival, 1.39; 95% confidence interval [CI], 1.06-1.82; P = 0.02). The number needed to treat for a 30-day survival was 112 patients (95% CI, 63-500).

For the secondary outcomes, the epinephrine group had a higher survival until hospital admission: 947 patients (23.8%) as compared to 319 (8.0%) patients in the placebo group (unadjusted OR, 3.59). Otherwise, there were no difference between the 2 groups in the hospital and ICU LOS. There also was not a significant difference between the epinephrine group and the placebo group in the proportion of patients who survived until hospital discharge: 87 of 4007 patients (2.2%) in the epinephrine group and 74 of 3994 patients (1.9%) in the placebo group, with an unadjusted OR of 1.18 (95% CI, 0.85-1.61). Patients in the epinephrine group had a higher rate of severe neurologic impairment at discharge: 39 of 126 patients (31.0%) versus 16 of 90 patients (17.8%).

Conclusion. Among adults with out-of-hospital cardiac arrest, the use of epinephrine resulted in a higher rate of 30-day survival as compared with the use of placebo; however, there was no difference in the rate of a favorable neurologic outcome as more survivors in the epinephrine group had severe neurologic impairment.

Commentary

Epinephrine has been used as part of the resuscitation of patients with cardiac arrest since the 1960s. Epinephrine increases vasomotor tone during circulatory collapse, shunts more blood to the heart, and increases the likelihood of restoring spontaneous circulation.¹ However, epinephrine also decreases microvascular blood flow and can result in long-term organ dysfunction or hypoperfusion of the heart and brain.² The current study, the PARAMEDIC2 trial, by Perkins and colleagues is the largest randomized controlled trial to date to address the question of patient-centered benefit of the use of epinephrine during out-of-hospital cardiac arrest.

Similar to prior studies, patients who received epinephrine had a higher rate of 30-day survival than those who received placebo. However, there was no clear improvement in functional recovery among patients who survived, and the proportion of survivors with severe neurologic impairment was higher in the epinephrine group as compared to the placebo group. These results demonstrate that despite its ability to restore spontaneous circulation after out-of-hospital cardiac arrest, epinephrine produced only a small absolute increase in survival with worse functional recovery as compared with placebo.

One major limitation of this study is that the protocol did not control for or measure in-hospital treatments. In a prior study, the most common cause of in-hospital death was iatrogenic limitation of life support, which may result in the death of potentially viable patients.³ Another limitation of the study was the timing to administration of epinephrine. In the current study, paramedics administered the trial agent within a median of 21 minutes after the emergency call, which is a longer duration than previous out-of-hospital trials.⁴ In addition, this time to administration is much longer than that of in-hospital cardiac arrest, where epinephrine is administered a median of 3 minutes after resuscitation starts.⁵ Therefore, the results from this study cannot be extrapolated to patients with in-hospital cardiac arrest.

Applications for Clinical Practice

The current study by Perkins et al demonstrated the powerful effect of epinephrine in restoring spontaneous circulation after out-of-hospital cardiac arrest. However, epinephrine produced only a small absolute increase in survival with worse functional recovery, as compared to placebo. While further studies regarding dosage of epinephrine as well as administration based on the basis of cardiac rhythm are needed, we should question our tradition of using epinephrine in out-of-hospital cardiac arrest if meaningful neurological function is our priority.

—Ka Ming Gordon Ngai, MD, MPH, FACEP

Study Overview

Objective. To assess the safety and effectiveness of the use of epinephrine in out-of-hospital cardiac arrest patients.

Design. Randomized, double-blind placebo-controlled trial in the United Kingdom.

Setting and participants. Patients aged 16 years or older who had sustained an out-of-hospital cardiac arrest for which advanced life support was provided by trial-trained paramedics were eligible for inclusion. Exclusion criteria included apparent pregnancy, arrest from anaphylaxis or asthma, or the administration of epinephrine before the arrival of the trial-trained paramedic. In 1 of the 5 ambulance services, traumatic cardiac arrests were also excluded in accordance with local protocol.

Main outcome measures. The primary outcome was the rate of survival at 30 days. Secondary outcomes included rate of survival until hospital admission, length of stay in the hospital and intensive care unit (ICU), rates of survival at hospital discharge and at 3 months, and neurologic outcomes at hospital discharge and at 3 months.

Main results. Between December 2014 and October 2017, 10,623 patients were screened for eligibility in 5 National Health Service ambulance services in the United Kingdom. Of these, 8103 were eligible, and 8014 patients were assigned to either the epinephrine group (4015 patients) or the placebo group (3999 patients).

For the primary outcome, 130 patients (3.2%) in the epinephrine group were alive at 30 days in comparison to 94 patients (2.4%) in the placebo group (unadjusted odds ratio [OR] for survival, 1.39; 95% confidence interval [CI], 1.06-1.82; P = 0.02). The number needed to treat for a 30-day survival was 112 patients (95% CI, 63-500).

For the secondary outcomes, the epinephrine group had a higher survival until hospital admission: 947 patients (23.8%) as compared to 319 (8.0%) patients in the placebo group (unadjusted OR, 3.59). Otherwise, there were no difference between the 2 groups in the hospital and ICU LOS. There also was not a significant difference between the epinephrine group and the placebo group in the proportion of patients who survived until hospital discharge: 87 of 4007 patients (2.2%) in the epinephrine group and 74 of 3994 patients (1.9%) in the placebo group, with an unadjusted OR of 1.18 (95% CI, 0.85-1.61). Patients in the epinephrine group had a higher rate of severe neurologic impairment at discharge: 39 of 126 patients (31.0%) versus 16 of 90 patients (17.8%).

Conclusion. Among adults with out-of-hospital cardiac arrest, the use of epinephrine resulted in a higher rate of 30-day survival as compared with the use of placebo; however, there was no difference in the rate of a favorable neurologic outcome as more survivors in the epinephrine group had severe neurologic impairment.

Commentary

Epinephrine has been used as part of the resuscitation of patients with cardiac arrest since the 1960s. Epinephrine increases vasomotor tone during circulatory collapse, shunts more blood to the heart, and increases the likelihood of restoring spontaneous circulation.¹ However, epinephrine also decreases microvascular blood flow and can result in long-term organ dysfunction or hypoperfusion of the heart and brain.² The current study, the PARAMEDIC2 trial, by Perkins and colleagues is the largest randomized controlled trial to date to address the question of patient-centered benefit of the use of epinephrine during out-of-hospital cardiac arrest.

Similar to prior studies, patients who received epinephrine had a higher rate of 30-day survival than those who received placebo. However, there was no clear improvement in functional recovery among patients who survived, and the proportion of survivors with severe neurologic impairment was higher in the epinephrine group as compared to the placebo group. These results demonstrate that despite its ability to restore spontaneous circulation after out-of-hospital cardiac arrest, epinephrine produced only a small absolute increase in survival with worse functional recovery as compared with placebo.

One major limitation of this study is that the protocol did not control for or measure in-hospital treatments. In a prior study, the most common cause of in-hospital death was iatrogenic limitation of life support, which may result in the death of potentially viable patients.³ Another limitation of the study was the timing to administration of epinephrine. In the current study, paramedics administered the trial agent within a median of 21 minutes after the emergency call, which is a longer duration than previous out-of-hospital trials.⁴ In addition, this time to administration is much longer than that of in-hospital cardiac arrest, where epinephrine is administered a median of 3 minutes after resuscitation starts.⁵ Therefore, the results from this study cannot be extrapolated to patients with in-hospital cardiac arrest.

Applications for Clinical Practice

The current study by Perkins et al demonstrated the powerful effect of epinephrine in restoring spontaneous circulation after out-of-hospital cardiac arrest. However, epinephrine produced only a small absolute increase in survival with worse functional recovery, as compared to placebo. While further studies regarding dosage of epinephrine as well as administration based on the basis of cardiac rhythm are needed, we should question our tradition of using epinephrine in out-of-hospital cardiac arrest if meaningful neurological function is our priority.

—Ka Ming Gordon Ngai, MD, MPH, FACEP

The Food and Drug Administration on Nov. 2 approved sufentanil (Dsuvia) for managing acute pain in adult patients in certified, medically supervised health care settings.

Sufentanil, an opioid analgesic manufactured by AcelRx Pharmaceuticals, was approved as a 30-mcg sublingual tablet. The efficacy of Dsuvia was shown in a randomized, clinical trial where patients who received the drug demonstrated significantly greater pain relief after both 15 minutes and 12 hours, compared with placebo.

“As a single-dose, noninvasive medication with a rapid reduction in pain intensity, Dsuvia represents an important alternative for health care providers to offer patients for acute pain management,” David Leiman, MD, of the department of surgery at the University of Texas, Houston, said in the AcelRx press statement.

FDA Commissioner Scott Gottlieb, MD, commented on the approval amid concerns expressed by some, such as the advocacy group Public Citizen, that the drug is “more than 1,000 times more potent than morphine,” and that approval could lead to diversion and abuse – particularly in light of the U.S. opioid epidemic.

In his statement, Dr. Gottlieb identified one broad, significant issue. “Why do we need an oral formulation of sufentanil – a more potent form of fentanyl that’s been approved for intravenous and epidural use in the U.S. since 1984 – on the market?”

In particular, he focused on the needs of the military. The Department of Defense has taken interest in sufentanil as it fulfills a small but specific battlefield need, namely as a means of pain relief in battlefield situations where soldiers cannot swallow oral medication and access to intravenous medication is limited.

Dr. Gottlieb made clear that sufentanil was meant only to be taken in controlled settings and will have strong limitations on its use. It cannot be prescribed for home use, and treatment should be limited to 72 hours. It can only be delivered by health care professionals using a single-dose applicator and will not be available in pharmacies. It is only to be used in patients who have not tolerated or are expected not to tolerate alternative methods of pain management.

“The FDA has implemented a REMS [Risk Evaluation and Mitigation Strategy] that reflects the potential risks associated with this product and mandates that Dsuvia will only be made available for use in a certified medically supervised heath care setting, including its use on the battlefield,” Dr. Gottlieb said.

However, he recognized that the debate runs deeper than how the FDA should mitigate risk over a new drug, and “as a public health agency, we have an obligation to address this question openly and directly. As a physician and regulator, I won’t bypass legitimate questions and concerns related to our role in addressing the opioid crisis,” he said.

Find Dr. Gottlieb’s full statement on the FDA website.

[email protected]

The Food and Drug Administration on Nov. 2 approved sufentanil (Dsuvia) for managing acute pain in adult patients in certified, medically supervised health care settings.

Sufentanil, an opioid analgesic manufactured by AcelRx Pharmaceuticals, was approved as a 30-mcg sublingual tablet. The efficacy of Dsuvia was shown in a randomized, clinical trial where patients who received the drug demonstrated significantly greater pain relief after both 15 minutes and 12 hours, compared with placebo.

“As a single-dose, noninvasive medication with a rapid reduction in pain intensity, Dsuvia represents an important alternative for health care providers to offer patients for acute pain management,” David Leiman, MD, of the department of surgery at the University of Texas, Houston, said in the AcelRx press statement.

FDA Commissioner Scott Gottlieb, MD, commented on the approval amid concerns expressed by some, such as the advocacy group Public Citizen, that the drug is “more than 1,000 times more potent than morphine,” and that approval could lead to diversion and abuse – particularly in light of the U.S. opioid epidemic.

In his statement, Dr. Gottlieb identified one broad, significant issue. “Why do we need an oral formulation of sufentanil – a more potent form of fentanyl that’s been approved for intravenous and epidural use in the U.S. since 1984 – on the market?”

In particular, he focused on the needs of the military. The Department of Defense has taken interest in sufentanil as it fulfills a small but specific battlefield need, namely as a means of pain relief in battlefield situations where soldiers cannot swallow oral medication and access to intravenous medication is limited.

Dr. Gottlieb made clear that sufentanil was meant only to be taken in controlled settings and will have strong limitations on its use. It cannot be prescribed for home use, and treatment should be limited to 72 hours. It can only be delivered by health care professionals using a single-dose applicator and will not be available in pharmacies. It is only to be used in patients who have not tolerated or are expected not to tolerate alternative methods of pain management.

“The FDA has implemented a REMS [Risk Evaluation and Mitigation Strategy] that reflects the potential risks associated with this product and mandates that Dsuvia will only be made available for use in a certified medically supervised heath care setting, including its use on the battlefield,” Dr. Gottlieb said.

However, he recognized that the debate runs deeper than how the FDA should mitigate risk over a new drug, and “as a public health agency, we have an obligation to address this question openly and directly. As a physician and regulator, I won’t bypass legitimate questions and concerns related to our role in addressing the opioid crisis,” he said.

Find Dr. Gottlieb’s full statement on the FDA website.

[email protected]

The Food and Drug Administration on Nov. 2 approved sufentanil (Dsuvia) for managing acute pain in adult patients in certified, medically supervised health care settings.

Sufentanil, an opioid analgesic manufactured by AcelRx Pharmaceuticals, was approved as a 30-mcg sublingual tablet. The efficacy of Dsuvia was shown in a randomized, clinical trial where patients who received the drug demonstrated significantly greater pain relief after both 15 minutes and 12 hours, compared with placebo.

“As a single-dose, noninvasive medication with a rapid reduction in pain intensity, Dsuvia represents an important alternative for health care providers to offer patients for acute pain management,” David Leiman, MD, of the department of surgery at the University of Texas, Houston, said in the AcelRx press statement.

FDA Commissioner Scott Gottlieb, MD, commented on the approval amid concerns expressed by some, such as the advocacy group Public Citizen, that the drug is “more than 1,000 times more potent than morphine,” and that approval could lead to diversion and abuse – particularly in light of the U.S. opioid epidemic.

In his statement, Dr. Gottlieb identified one broad, significant issue. “Why do we need an oral formulation of sufentanil – a more potent form of fentanyl that’s been approved for intravenous and epidural use in the U.S. since 1984 – on the market?”

In particular, he focused on the needs of the military. The Department of Defense has taken interest in sufentanil as it fulfills a small but specific battlefield need, namely as a means of pain relief in battlefield situations where soldiers cannot swallow oral medication and access to intravenous medication is limited.

Dr. Gottlieb made clear that sufentanil was meant only to be taken in controlled settings and will have strong limitations on its use. It cannot be prescribed for home use, and treatment should be limited to 72 hours. It can only be delivered by health care professionals using a single-dose applicator and will not be available in pharmacies. It is only to be used in patients who have not tolerated or are expected not to tolerate alternative methods of pain management.

“The FDA has implemented a REMS [Risk Evaluation and Mitigation Strategy] that reflects the potential risks associated with this product and mandates that Dsuvia will only be made available for use in a certified medically supervised heath care setting, including its use on the battlefield,” Dr. Gottlieb said.

However, he recognized that the debate runs deeper than how the FDA should mitigate risk over a new drug, and “as a public health agency, we have an obligation to address this question openly and directly. As a physician and regulator, I won’t bypass legitimate questions and concerns related to our role in addressing the opioid crisis,” he said.

Find Dr. Gottlieb’s full statement on the FDA website.

[email protected]

A 49-year-old man developed nephrotic-range proteinuria (urine protein–creatinine ratio 4.1 g/g), and primary membranous nephropathy was diagnosed by kidney biopsy. He declined therapy apart from angiotensin receptor blockade.

Five months after undergoing the biopsy, he presented to the emergency room with marked dyspnea, cough, and epigastric discomfort. His blood pressure was 160/100 mm Hg, heart rate 95 beats/minute, and oxygen saturation by pulse oximetry 97% at rest on ambient air, decreasing to 92% with ambulation.

Initial laboratory testing results were as follows:

• Sodium 135 mmol/L (reference range 136–144)
• Potassium 3.9 mmol/L (3.7–5.1)
• Chloride 104 mmol/L (97–105)
• Bicarbonate 21 mmol/L (22–30)
• Blood urea nitrogen 14 mg/dL (9–24)
• Serum creatinine 1.1 mg/dL (0.73–1.22)
• Albumin 2.1 g/dL (3.4–4.9).

Urinalysis revealed the following:

• 5 red blood cells per high-power field, compared with 1 to 2 previously
• 3+ proteinuria
• Urine protein–creatinine ratio 11 g/g
• No glucosuria.

Electrocardiography revealed normal sinus rhythm without ischemic changes. Chest radiography did not show consolidation.

At 7 months after the thrombotic event, there was no evidence of residual renal vein thrombosis on magnetic resonance venography, and at 14 months his serum creatinine level was 0.9 mg/dL, albumin 4.0 g/dL, and urine protein–creatinine ratio 0.8 g/g.

RENAL VEIN THROMBOSIS: RISK FACTORS AND CLINICAL FEATURES

Severe hypoalbuminemia in the setting of nephrotic syndrome due to membranous neph­ropathy is associated with the highest risk of venous thromboembolic events, with renal vein thrombus being the classic complication.¹ Venous thromboembolic events also occur in other nephrotic syndromes, albeit at a lower frequency.²

Venous thromboembolic events are estimated to occur in 7% to 33% of patients with membranous glomerulopathy, with albumin levels less than 2.8 g/dL considered a notable risk factor.^1,2

While often a chronic complication, acute renal vein thrombosis may present with flank pain and hematuria.³ In our patient, the dramatic increase in proteinuria and possibly the increase in hematuria suggested renal vein thrombosis. Proximal tubular dysfunction, such as glucosuria, can be seen on occasion.

DIAGNOSIS AND TREATMENT

Screening asymptomatic patients for renal vein thrombosis is not recommended, and the decision to start prophylactic anticoagulation must be individualized.⁴

Although renal venography historically was the gold standard test to diagnose renal vein thrombosis, it has been replaced by noninvasive imaging such as computed tomography and magnetic resonance venography.

While anticoagulation remains the treatment of choice, catheter-directed thrombectomy or surgical thrombectomy can be considered for some patients with acute renal vein thrombosis.⁵

A 49-year-old man developed nephrotic-range proteinuria (urine protein–creatinine ratio 4.1 g/g), and primary membranous nephropathy was diagnosed by kidney biopsy. He declined therapy apart from angiotensin receptor blockade.

Five months after undergoing the biopsy, he presented to the emergency room with marked dyspnea, cough, and epigastric discomfort. His blood pressure was 160/100 mm Hg, heart rate 95 beats/minute, and oxygen saturation by pulse oximetry 97% at rest on ambient air, decreasing to 92% with ambulation.

Initial laboratory testing results were as follows:

• Sodium 135 mmol/L (reference range 136–144)
• Potassium 3.9 mmol/L (3.7–5.1)
• Chloride 104 mmol/L (97–105)
• Bicarbonate 21 mmol/L (22–30)
• Blood urea nitrogen 14 mg/dL (9–24)
• Serum creatinine 1.1 mg/dL (0.73–1.22)
• Albumin 2.1 g/dL (3.4–4.9).

Urinalysis revealed the following:

• 5 red blood cells per high-power field, compared with 1 to 2 previously
• 3+ proteinuria
• Urine protein–creatinine ratio 11 g/g
• No glucosuria.

Electrocardiography revealed normal sinus rhythm without ischemic changes. Chest radiography did not show consolidation.

At 7 months after the thrombotic event, there was no evidence of residual renal vein thrombosis on magnetic resonance venography, and at 14 months his serum creatinine level was 0.9 mg/dL, albumin 4.0 g/dL, and urine protein–creatinine ratio 0.8 g/g.

RENAL VEIN THROMBOSIS: RISK FACTORS AND CLINICAL FEATURES

Severe hypoalbuminemia in the setting of nephrotic syndrome due to membranous neph­ropathy is associated with the highest risk of venous thromboembolic events, with renal vein thrombus being the classic complication.¹ Venous thromboembolic events also occur in other nephrotic syndromes, albeit at a lower frequency.²

Venous thromboembolic events are estimated to occur in 7% to 33% of patients with membranous glomerulopathy, with albumin levels less than 2.8 g/dL considered a notable risk factor.^1,2

While often a chronic complication, acute renal vein thrombosis may present with flank pain and hematuria.³ In our patient, the dramatic increase in proteinuria and possibly the increase in hematuria suggested renal vein thrombosis. Proximal tubular dysfunction, such as glucosuria, can be seen on occasion.

DIAGNOSIS AND TREATMENT

Screening asymptomatic patients for renal vein thrombosis is not recommended, and the decision to start prophylactic anticoagulation must be individualized.⁴

Although renal venography historically was the gold standard test to diagnose renal vein thrombosis, it has been replaced by noninvasive imaging such as computed tomography and magnetic resonance venography.

While anticoagulation remains the treatment of choice, catheter-directed thrombectomy or surgical thrombectomy can be considered for some patients with acute renal vein thrombosis.⁵

A 49-year-old man developed nephrotic-range proteinuria (urine protein–creatinine ratio 4.1 g/g), and primary membranous nephropathy was diagnosed by kidney biopsy. He declined therapy apart from angiotensin receptor blockade.

Five months after undergoing the biopsy, he presented to the emergency room with marked dyspnea, cough, and epigastric discomfort. His blood pressure was 160/100 mm Hg, heart rate 95 beats/minute, and oxygen saturation by pulse oximetry 97% at rest on ambient air, decreasing to 92% with ambulation.

Initial laboratory testing results were as follows:

• Sodium 135 mmol/L (reference range 136–144)
• Potassium 3.9 mmol/L (3.7–5.1)
• Chloride 104 mmol/L (97–105)
• Bicarbonate 21 mmol/L (22–30)
• Blood urea nitrogen 14 mg/dL (9–24)
• Serum creatinine 1.1 mg/dL (0.73–1.22)
• Albumin 2.1 g/dL (3.4–4.9).

Urinalysis revealed the following:

• 5 red blood cells per high-power field, compared with 1 to 2 previously
• 3+ proteinuria
• Urine protein–creatinine ratio 11 g/g
• No glucosuria.

Electrocardiography revealed normal sinus rhythm without ischemic changes. Chest radiography did not show consolidation.

At 7 months after the thrombotic event, there was no evidence of residual renal vein thrombosis on magnetic resonance venography, and at 14 months his serum creatinine level was 0.9 mg/dL, albumin 4.0 g/dL, and urine protein–creatinine ratio 0.8 g/g.

RENAL VEIN THROMBOSIS: RISK FACTORS AND CLINICAL FEATURES

Severe hypoalbuminemia in the setting of nephrotic syndrome due to membranous neph­ropathy is associated with the highest risk of venous thromboembolic events, with renal vein thrombus being the classic complication.¹ Venous thromboembolic events also occur in other nephrotic syndromes, albeit at a lower frequency.²

Venous thromboembolic events are estimated to occur in 7% to 33% of patients with membranous glomerulopathy, with albumin levels less than 2.8 g/dL considered a notable risk factor.^1,2

While often a chronic complication, acute renal vein thrombosis may present with flank pain and hematuria.³ In our patient, the dramatic increase in proteinuria and possibly the increase in hematuria suggested renal vein thrombosis. Proximal tubular dysfunction, such as glucosuria, can be seen on occasion.

DIAGNOSIS AND TREATMENT

Screening asymptomatic patients for renal vein thrombosis is not recommended, and the decision to start prophylactic anticoagulation must be individualized.⁴

Although renal venography historically was the gold standard test to diagnose renal vein thrombosis, it has been replaced by noninvasive imaging such as computed tomography and magnetic resonance venography.

While anticoagulation remains the treatment of choice, catheter-directed thrombectomy or surgical thrombectomy can be considered for some patients with acute renal vein thrombosis.⁵

Most patients admitted with pulmonary embolism (PE) do not need transthoracic echocardiography (TTE); it should be performed in hemodynamically unstable patients, as well as in hemodynamically stable patients with specific elevated cardiac biomarkers and imaging features.

The decision to perform TTE should be based on clinical presentation, PE burden, and imaging findings (eg, computed tomographic angiography). TTE helps to stratify risk, guide management, monitor response to therapy, and give prognostic information for a subset of patients at increased risk for PE-related adverse events.

RISK STRATIFICATION IN PULMONARY EMBOLISM

PE has a spectrum of presentations ranging from no symptoms to shock. Based on the clinical presentation, PE can be categorized as high, intermediate, or low risk.

High-risk PE, often referred to as “massive” PE, is defined in current American Heart Association guidelines as acute PE with sustained hypotension (systolic blood pressure < 90 mm Hg for at least 15 minutes or requiring inotropic support), persistent profound bradycardia (heart rate < 40 beats per minute with signs or symptoms of shock), syncope, or cardiac arrest.¹

Intermediate-risk or “submassive” PE is more challenging to identify because patients are more hemodynamically stable, yet have evidence on electrocardiography, TTE, computed tomography, or cardiac biomarker testing—ie, N-terminal pro-B-type natriuretic peptide (NT-proBNP) or troponin—that indicates myocardial injury or volume overload.¹

Low-risk PE is acute PE in the absence of clinical markers of adverse prognosis that define massive or submassive PE.¹

ECHOCARDIOGRAPHIC FEATURES OF HIGH-RISK PULMONARY EMBOLISM

Certain TTE findings suggest increased risk of a poor outcome and may warrant therapy that is more invasive and aggressive. High-risk features include the following:

• Impaired right ventricular function
• Interventricular septum bulging into the left ventricle (“D-shaped” septum)
• Dilated proximal pulmonary arteries
• Increased severity of tricuspid regurgitation
• Elevated right atrial pressure
• Elevated pulmonary artery pressure
• Free-floating right ventricular thrombi, which are associated with a mortality rate of up to 45% and can be detected in 7% to 18% of patients⁶
• Tricuspid annular plane systolic excursion, an echocardiographic measure of right ventricular function¹; a value less than 17 mm suggests impaired right ventricular systolic function⁷
• The McConnell sign, a feature of acute massive PE: akinesia of the mid-free wall of the right ventricle and hypercontractility of the apex.

These TTE findings often lead to treatment with thrombolysis, transfer to the intensive care unit, and activation of the interventional team for catheter-based therapies.^1,8 Free-floating right heart thrombi or thrombus straddling the interatrial septum (“thrombus in transit”) through a patent foramen ovale may require surgical embolectomy.⁸

PATIENT SELECTION AND INDICATIONS FOR ECHOCARDIOGRAPHY

Most patients admitted with pulmonary embolism (PE) do not need transthoracic echocardiography (TTE); it should be performed in hemodynamically unstable patients, as well as in hemodynamically stable patients with specific elevated cardiac biomarkers and imaging features.

The decision to perform TTE should be based on clinical presentation, PE burden, and imaging findings (eg, computed tomographic angiography). TTE helps to stratify risk, guide management, monitor response to therapy, and give prognostic information for a subset of patients at increased risk for PE-related adverse events.

RISK STRATIFICATION IN PULMONARY EMBOLISM

PE has a spectrum of presentations ranging from no symptoms to shock. Based on the clinical presentation, PE can be categorized as high, intermediate, or low risk.

High-risk PE, often referred to as “massive” PE, is defined in current American Heart Association guidelines as acute PE with sustained hypotension (systolic blood pressure < 90 mm Hg for at least 15 minutes or requiring inotropic support), persistent profound bradycardia (heart rate < 40 beats per minute with signs or symptoms of shock), syncope, or cardiac arrest.¹

Intermediate-risk or “submassive” PE is more challenging to identify because patients are more hemodynamically stable, yet have evidence on electrocardiography, TTE, computed tomography, or cardiac biomarker testing—ie, N-terminal pro-B-type natriuretic peptide (NT-proBNP) or troponin—that indicates myocardial injury or volume overload.¹

Low-risk PE is acute PE in the absence of clinical markers of adverse prognosis that define massive or submassive PE.¹

ECHOCARDIOGRAPHIC FEATURES OF HIGH-RISK PULMONARY EMBOLISM

Certain TTE findings suggest increased risk of a poor outcome and may warrant therapy that is more invasive and aggressive. High-risk features include the following:

• Impaired right ventricular function
• Interventricular septum bulging into the left ventricle (“D-shaped” septum)
• Dilated proximal pulmonary arteries
• Increased severity of tricuspid regurgitation
• Elevated right atrial pressure
• Elevated pulmonary artery pressure
• Free-floating right ventricular thrombi, which are associated with a mortality rate of up to 45% and can be detected in 7% to 18% of patients⁶
• Tricuspid annular plane systolic excursion, an echocardiographic measure of right ventricular function¹; a value less than 17 mm suggests impaired right ventricular systolic function⁷
• The McConnell sign, a feature of acute massive PE: akinesia of the mid-free wall of the right ventricle and hypercontractility of the apex.

These TTE findings often lead to treatment with thrombolysis, transfer to the intensive care unit, and activation of the interventional team for catheter-based therapies.^1,8 Free-floating right heart thrombi or thrombus straddling the interatrial septum (“thrombus in transit”) through a patent foramen ovale may require surgical embolectomy.⁸

PATIENT SELECTION AND INDICATIONS FOR ECHOCARDIOGRAPHY

Most patients admitted with pulmonary embolism (PE) do not need transthoracic echocardiography (TTE); it should be performed in hemodynamically unstable patients, as well as in hemodynamically stable patients with specific elevated cardiac biomarkers and imaging features.

The decision to perform TTE should be based on clinical presentation, PE burden, and imaging findings (eg, computed tomographic angiography). TTE helps to stratify risk, guide management, monitor response to therapy, and give prognostic information for a subset of patients at increased risk for PE-related adverse events.

RISK STRATIFICATION IN PULMONARY EMBOLISM

PE has a spectrum of presentations ranging from no symptoms to shock. Based on the clinical presentation, PE can be categorized as high, intermediate, or low risk.

High-risk PE, often referred to as “massive” PE, is defined in current American Heart Association guidelines as acute PE with sustained hypotension (systolic blood pressure < 90 mm Hg for at least 15 minutes or requiring inotropic support), persistent profound bradycardia (heart rate < 40 beats per minute with signs or symptoms of shock), syncope, or cardiac arrest.¹

Intermediate-risk or “submassive” PE is more challenging to identify because patients are more hemodynamically stable, yet have evidence on electrocardiography, TTE, computed tomography, or cardiac biomarker testing—ie, N-terminal pro-B-type natriuretic peptide (NT-proBNP) or troponin—that indicates myocardial injury or volume overload.¹

Low-risk PE is acute PE in the absence of clinical markers of adverse prognosis that define massive or submassive PE.¹

ECHOCARDIOGRAPHIC FEATURES OF HIGH-RISK PULMONARY EMBOLISM

Certain TTE findings suggest increased risk of a poor outcome and may warrant therapy that is more invasive and aggressive. High-risk features include the following:

• Impaired right ventricular function
• Interventricular septum bulging into the left ventricle (“D-shaped” septum)
• Dilated proximal pulmonary arteries
• Increased severity of tricuspid regurgitation
• Elevated right atrial pressure
• Elevated pulmonary artery pressure
• Free-floating right ventricular thrombi, which are associated with a mortality rate of up to 45% and can be detected in 7% to 18% of patients⁶
• Tricuspid annular plane systolic excursion, an echocardiographic measure of right ventricular function¹; a value less than 17 mm suggests impaired right ventricular systolic function⁷
• The McConnell sign, a feature of acute massive PE: akinesia of the mid-free wall of the right ventricle and hypercontractility of the apex.

These TTE findings often lead to treatment with thrombolysis, transfer to the intensive care unit, and activation of the interventional team for catheter-based therapies.^1,8 Free-floating right heart thrombi or thrombus straddling the interatrial septum (“thrombus in transit”) through a patent foramen ovale may require surgical embolectomy.⁸

PATIENT SELECTION AND INDICATIONS FOR ECHOCARDIOGRAPHY

A 76-year-old man whose history included abdominal aortic aneurysm repair, bilateral femoral artery bypass for popliteal artery aneurysm, hypertension, and peptic ulcer disease was admitted to a community hospital with pleuritic chest pain and shortness of breath. Two days earlier, he had undergone repair of a ventral hernia.

At the time of that admission, he reported no fever, chills, night sweats, cough, or history of heart or lung disease. His vital signs were normal, and physical examination had revealed no apparent respiratory distress, no jugular venous distention, normal heart sounds, and no pedal edema; however, decreased air entry was noted in the right lung base. Initial serum levels of troponin and N-terminal pro-B-type natriuretic peptide were normal.

At that time, computed tomographic angiography of the chest showed segmental pulmonary emboli in the left upper and right lower lobes of the lungs and right pleural effusion. Transthoracic echocardiography showed normal atrial and ventricular sizes with no right or left ventricular systolic dysfunction and a left ventricular ejection fraction of 59%.

Treatment with intravenous heparin was started, and the patient was transferred to our hospital.

PLEURAL EFFUSION AND PULMONARY EMBOLISM

1. Which of the following is true about pleural effusion?

• It is rarely, if ever, associated with pulmonary embolism
• Most patients with pleural effusion due to pulmonary embolism do not have pleuritic chest pain
• Pulmonary embolism should be excluded in all cases of pleural effusion without a clear cause

Pulmonary embolism should be excluded in all cases of pleural effusion that do not have a clear cause. As for the other answer choices:

• Pulmonary embolism is the fourth leading cause of pleural effusion in the United States, after heart failure, pneumonia, and malignancy.¹
• About 75% of patients who develop pleural effusion in the setting of pulmonary embolism complain of pleuritic chest pain on the side of the effusion.² Most effusions are unilateral, small, and usually exudative.³

EVALUATION BEGINS: RESULTS OF THORACENTESIS

Our patient continued to receive intravenous heparin.

He underwent thoracentesis on hospital day 3, and 1,000 mL of turbid sanguineous pleural fluid was removed. Analysis of the fluid showed pH 7.27, white blood cell count 3.797 × 10⁹/L with 80% neutrophils, and lactate dehydrogenase (LDH) concentration 736 U/L (a ratio of pleural fluid LDH to a concurrent serum LDH > 0.6 is suggestive of an exudate); the fluid was also sent for culture and cytology. Thoracentesis was terminated early due to cough, and follow-up chest radiography showed a moderate-sized pneumothorax.

Computed tomography (CT) of the chest at this time showed a small wedge-shaped area of lung consolidation in the right lower lobe (also seen on CT done 1 day before admission to our hospital), with an intrinsic air-fluid level suggesting a focal infarct or lung abscess, now obscured by adjacent consolidation and atelectasis. In the interval since the previous CT, the multiloculated right pleural effusion had increased in size (Figure 1).

THE NEXT STEP

2. What is the most appropriate next step for this patient?

• Consult an interventional radiologist for chest tube placement
• Start empiric antibiotic therapy and ask an interventional radiologist to place a chest tube
• Start empiric antibiotic therapy, withhold anticoagulation, and consult a thoracic surgeon
• Start empiric antibiotic therapy and consult a thoracic surgeon while continuing anticoagulation

The most appropriate next step is to start empiric antibiotic therapy and consult a thoracic surgeon while continuing anticoagulation.

In this patient, it is appropriate to initiate antibiotics empirically on the basis of his significant pleural loculations, a wedge-shaped consolidation, and 80% neutrophils in the pleural fluid, all of which suggest infection. The unmasking of a wedge-shaped consolidation after thoracentesis, with a previously noted air-fluid level and an interval increase in multiloculated pleural fluid, raises suspicion of a necrotic infection that may have ruptured into the pleural space, a possible lung infarct, or a malignancy. Hence, simply placing a chest tube may not be enough.

Blood in the pleural fluid does not necessitate withholding anticoagulation unless the bleeding is heavy. A pleural fluid hematocrit greater than 50% of the peripheral blood hematocrit suggests hemothorax and is an indication to withhold anticoagulation.¹ Our patient’s pleural fluid was qualitatively sanguineous but not frankly bloody, and therefore we judged that it was not necessary to stop his heparin.

HOW DOES PULMONARY INFARCTION PRESENT CLINICALLY?

3. Which of the following statements about pulmonary infarction is incorrect?

• Cavitation and infarction are more common with larger emboli
• Cavitation occurs in fewer than 10% of pulmonary infarctions
• Lung abscess develops in more than 50% of pulmonary infarctions
• Pulmonary thromboembolism is the most common cause of pulmonary infarction

Lung abscess develops in far fewer than 50% of cases of pulmonary infarction. The rest of the statements are correct.

Cavitation complicates about 4% to 7% of infarctions and is more common when the infarction is 4 cm or greater in diameter.⁴ These cavities are usually single and predominantly on the right side in the apical or posterior segment of the upper lobe or the apical segment of the right lower lobe, as in our patient.^5–8 CT demonstrating scalloped inner margins and cross-cavity band shadows suggests a cavitary pulmonary infarction.^9,10

Infection and abscess in pulmonary infarction are poorly understood but have been linked to larger infarctions, coexistent congestion or atelectasis, and dental or oropharyngeal infection. In an early series of 550 cases of pulmonary infarction, 23 patients (4.2%) developed lung abscess and 6 (1.1%) developed empyema.¹¹ The mean time to cavitation for an infected pulmonary infarction has been reported to be 18 days.¹²

A reversed halo sign, generally described as a focal, rounded area of ground-glass opacity surrounded by a nearly complete ring of consolidation, has been reported to be more frequent with pulmonary infarction than with other diseases, especially when in the lower lobes.¹³

CASE CONTINUED: THORACOSCOPY

A cardiothoracic surgeon was consulted, intravenous heparin was discontinued, an inferior vena cava filter was placed, and the patient underwent video-assisted thoracoscopy.

Purulent fluid was noted on the lateral aspect of right lower lobe; this appeared to be the ruptured cavitary lesion functioning like an uncontrolled bronchopleural fistula. Two chest tubes, sizes 32F and 28F, were placed after decortication, resection of the lung abscess, and closure of the bronchopleural fistula. No significant air leak was noted after resection of this segment of lung.

Pathologic study showed acute organizing pneumonia with abscess formation; no malignant cells or granulomas were seen (Figure 2). Pleural fluid cultures grew Streptococcus intermedius, while the tissue culture was negative for any growth, including acid-fast bacilli and fungi.

On 3 different occasions, both chest tubes were shortened, backed out 2 cm, and resecured with sutures and pins, and Heimlich valves were applied before the patient was discharged.

Intravenous piperacillin-tazobactam was started on the fifth hospital day. On discharge, the patient was advised to continue this treatment for 3 weeks at home.

The patient was receiving enoxaparin subcutaneously in prophylactic doses; 72 hours after the thorascopic procedure this was increased to therapeutic doses, continuing after discharge. Bridging to warfarin was not advised in view of his chest tubes.

Our patient appeared to have developed a right lower lobe infarction that cavitated and ruptured into the pleural space, causing a bronchopleural fistula with empyema after a recent pulmonary embolism. Other reported causes of pulmonary infarction in pulmonary embolism are malignancy and heavy clot burden,⁶ but these have not been confirmed in subsequent studies.⁵ Malignancy was ruled out by biopsy of the resected portion of the lung, and our patient did not have a history of heart failure. A clear cavity was not noted (because it ruptured into the pleura), but an air-fluid level was described in a wedge-shaped consolidation, suggesting infarction.

How common is pulmonary infarction after pulmonary embolism?

Pulmonary infarction occurs in few patients with pulmonary embolism.¹³ Since the lungs receive oxygen from the airways and have a dual blood supply from the pulmonary and bronchial arteries, they are not particularly vulnerable to ischemia. However, the reported incidence of pulmonary infarction in patients with pulmonary embolism has ranged from 10% to higher than 30%.^5,14,15

The reasons behind pulmonary infarction with complications after pulmonary embolism have varied in different case series in different eras. CT, biopsy, or autopsy studies reveal pulmonary infarction after pulmonary embolism to be more common than suspected by clinical symptoms.

In a Mayo Clinic series of 43 cases of pulmonary infarction diagnosed over a 6-year period by surgical lung biopsy, 18 (42%) of the patients had underlying pulmonary thromboembolism, which was the most common cause.¹⁶

4. Which statement about risk factors for pulmonary infarction in pulmonary embolism is incorrect?

• Heart failure may be a risk factor for pulmonary infarction
• Pulmonary hemorrhage is a risk factor for pulmonary infarction
• Pulmonary infarction is more common with more proximal sites of pulmonary embolism
• Collateral circulation may protect against pulmonary infarction

Infarction is more common with emboli that are distal rather than proximal.

Dalen et al¹⁵ suggested that after pulmonary embolism, pulmonary hemorrhage is an important contributor to the development of pulmonary infarction independent of the presence or absence of associated cardiac or pulmonary disease, but that the effect depends on the site of obstruction.

This idea was first proposed in 1913, when Karsner and Ghoreyeb¹⁷ showed that when pulmonary arteries are completely obstructed, the bronchial arteries take over, except when the embolism is present in a small branch of the pulmonary artery. This is because the physiologic anastomosis between the pulmonary artery and the bronchial arteries is located at the precapillary level of the pulmonary artery, and the bronchial circulation does not take over until the pulmonary arterial pressure in the area of the embolism drops to zero.

Using CT data, Kirchner et al⁵ confirmed that the risk of pulmonary infarction is higher if the obstruction is peripheral, ie, distal.

Using autopsy data, Tsao et al¹⁸ reported a higher risk of pulmonary infarction in embolic occlusion of pulmonary vessels less than 3 mm in diameter.

Collateral circulation has been shown to protect against pulmonary infarction. For example, Miniati et al¹⁴ showed that healthy young patients with pulmonary embolism were more prone to develop pulmonary infarction, probably because they had less efficient collateral systems in the peripheral lung fields. In lung transplant recipients, it has been shown that the risk of infarction decreased with development of collateral circulation.¹⁹

Dalen et al,¹⁵ however, attributed delayed resolution of pulmonary hemorrhage (as measured by resolution of infiltrate on chest radiography) to higher underlying pulmonary venous pressure in patients with heart failure and consequent pulmonary infarction. In comparison, healthy patients without cardiac or pulmonary disease have faster resolution of pulmonary hemorrhage when present, and less likelihood of pulmonary infarction (and death in submassive pulmonary embolism).

Data on the management of infected pulmonary infarction are limited. Mortality rates have been as high as 41% with noninfected and 73% with infected cavitary infarctions.⁴ Some authors have advocated early surgical resection in view of high rates of failure of medical treatment due to lack of blood supply within the cavity and continued risk of infection.

KEY POINTS

In patients with a recently diagnosed pulmonary embolism and concurrent symptoms of bacterial pneumonia, a diagnosis of cavitary pulmonary infarction should be considered.

Consolidations that are pleural-based with sharp, rounded margins and with focal areas of central hyperlucencies representing hemorrhage on the mediastinal windows on CT are more likely to represent a pulmonary infarct.²⁰

A 76-year-old man whose history included abdominal aortic aneurysm repair, bilateral femoral artery bypass for popliteal artery aneurysm, hypertension, and peptic ulcer disease was admitted to a community hospital with pleuritic chest pain and shortness of breath. Two days earlier, he had undergone repair of a ventral hernia.

At the time of that admission, he reported no fever, chills, night sweats, cough, or history of heart or lung disease. His vital signs were normal, and physical examination had revealed no apparent respiratory distress, no jugular venous distention, normal heart sounds, and no pedal edema; however, decreased air entry was noted in the right lung base. Initial serum levels of troponin and N-terminal pro-B-type natriuretic peptide were normal.

At that time, computed tomographic angiography of the chest showed segmental pulmonary emboli in the left upper and right lower lobes of the lungs and right pleural effusion. Transthoracic echocardiography showed normal atrial and ventricular sizes with no right or left ventricular systolic dysfunction and a left ventricular ejection fraction of 59%.

Treatment with intravenous heparin was started, and the patient was transferred to our hospital.

PLEURAL EFFUSION AND PULMONARY EMBOLISM

1. Which of the following is true about pleural effusion?

• It is rarely, if ever, associated with pulmonary embolism
• Most patients with pleural effusion due to pulmonary embolism do not have pleuritic chest pain
• Pulmonary embolism should be excluded in all cases of pleural effusion without a clear cause

Pulmonary embolism should be excluded in all cases of pleural effusion that do not have a clear cause. As for the other answer choices:

• Pulmonary embolism is the fourth leading cause of pleural effusion in the United States, after heart failure, pneumonia, and malignancy.¹
• About 75% of patients who develop pleural effusion in the setting of pulmonary embolism complain of pleuritic chest pain on the side of the effusion.² Most effusions are unilateral, small, and usually exudative.³

EVALUATION BEGINS: RESULTS OF THORACENTESIS

Our patient continued to receive intravenous heparin.

He underwent thoracentesis on hospital day 3, and 1,000 mL of turbid sanguineous pleural fluid was removed. Analysis of the fluid showed pH 7.27, white blood cell count 3.797 × 10⁹/L with 80% neutrophils, and lactate dehydrogenase (LDH) concentration 736 U/L (a ratio of pleural fluid LDH to a concurrent serum LDH > 0.6 is suggestive of an exudate); the fluid was also sent for culture and cytology. Thoracentesis was terminated early due to cough, and follow-up chest radiography showed a moderate-sized pneumothorax.

Computed tomography (CT) of the chest at this time showed a small wedge-shaped area of lung consolidation in the right lower lobe (also seen on CT done 1 day before admission to our hospital), with an intrinsic air-fluid level suggesting a focal infarct or lung abscess, now obscured by adjacent consolidation and atelectasis. In the interval since the previous CT, the multiloculated right pleural effusion had increased in size (Figure 1).

THE NEXT STEP

2. What is the most appropriate next step for this patient?

• Consult an interventional radiologist for chest tube placement
• Start empiric antibiotic therapy and ask an interventional radiologist to place a chest tube
• Start empiric antibiotic therapy, withhold anticoagulation, and consult a thoracic surgeon
• Start empiric antibiotic therapy and consult a thoracic surgeon while continuing anticoagulation

The most appropriate next step is to start empiric antibiotic therapy and consult a thoracic surgeon while continuing anticoagulation.

In this patient, it is appropriate to initiate antibiotics empirically on the basis of his significant pleural loculations, a wedge-shaped consolidation, and 80% neutrophils in the pleural fluid, all of which suggest infection. The unmasking of a wedge-shaped consolidation after thoracentesis, with a previously noted air-fluid level and an interval increase in multiloculated pleural fluid, raises suspicion of a necrotic infection that may have ruptured into the pleural space, a possible lung infarct, or a malignancy. Hence, simply placing a chest tube may not be enough.

Blood in the pleural fluid does not necessitate withholding anticoagulation unless the bleeding is heavy. A pleural fluid hematocrit greater than 50% of the peripheral blood hematocrit suggests hemothorax and is an indication to withhold anticoagulation.¹ Our patient’s pleural fluid was qualitatively sanguineous but not frankly bloody, and therefore we judged that it was not necessary to stop his heparin.

HOW DOES PULMONARY INFARCTION PRESENT CLINICALLY?

3. Which of the following statements about pulmonary infarction is incorrect?

• Cavitation and infarction are more common with larger emboli
• Cavitation occurs in fewer than 10% of pulmonary infarctions
• Lung abscess develops in more than 50% of pulmonary infarctions
• Pulmonary thromboembolism is the most common cause of pulmonary infarction

Lung abscess develops in far fewer than 50% of cases of pulmonary infarction. The rest of the statements are correct.

Cavitation complicates about 4% to 7% of infarctions and is more common when the infarction is 4 cm or greater in diameter.⁴ These cavities are usually single and predominantly on the right side in the apical or posterior segment of the upper lobe or the apical segment of the right lower lobe, as in our patient.^5–8 CT demonstrating scalloped inner margins and cross-cavity band shadows suggests a cavitary pulmonary infarction.^9,10

Infection and abscess in pulmonary infarction are poorly understood but have been linked to larger infarctions, coexistent congestion or atelectasis, and dental or oropharyngeal infection. In an early series of 550 cases of pulmonary infarction, 23 patients (4.2%) developed lung abscess and 6 (1.1%) developed empyema.¹¹ The mean time to cavitation for an infected pulmonary infarction has been reported to be 18 days.¹²

A reversed halo sign, generally described as a focal, rounded area of ground-glass opacity surrounded by a nearly complete ring of consolidation, has been reported to be more frequent with pulmonary infarction than with other diseases, especially when in the lower lobes.¹³

CASE CONTINUED: THORACOSCOPY

A cardiothoracic surgeon was consulted, intravenous heparin was discontinued, an inferior vena cava filter was placed, and the patient underwent video-assisted thoracoscopy.

Purulent fluid was noted on the lateral aspect of right lower lobe; this appeared to be the ruptured cavitary lesion functioning like an uncontrolled bronchopleural fistula. Two chest tubes, sizes 32F and 28F, were placed after decortication, resection of the lung abscess, and closure of the bronchopleural fistula. No significant air leak was noted after resection of this segment of lung.

Pathologic study showed acute organizing pneumonia with abscess formation; no malignant cells or granulomas were seen (Figure 2). Pleural fluid cultures grew Streptococcus intermedius, while the tissue culture was negative for any growth, including acid-fast bacilli and fungi.

On 3 different occasions, both chest tubes were shortened, backed out 2 cm, and resecured with sutures and pins, and Heimlich valves were applied before the patient was discharged.

Intravenous piperacillin-tazobactam was started on the fifth hospital day. On discharge, the patient was advised to continue this treatment for 3 weeks at home.

The patient was receiving enoxaparin subcutaneously in prophylactic doses; 72 hours after the thorascopic procedure this was increased to therapeutic doses, continuing after discharge. Bridging to warfarin was not advised in view of his chest tubes.

Our patient appeared to have developed a right lower lobe infarction that cavitated and ruptured into the pleural space, causing a bronchopleural fistula with empyema after a recent pulmonary embolism. Other reported causes of pulmonary infarction in pulmonary embolism are malignancy and heavy clot burden,⁶ but these have not been confirmed in subsequent studies.⁵ Malignancy was ruled out by biopsy of the resected portion of the lung, and our patient did not have a history of heart failure. A clear cavity was not noted (because it ruptured into the pleura), but an air-fluid level was described in a wedge-shaped consolidation, suggesting infarction.

How common is pulmonary infarction after pulmonary embolism?

Pulmonary infarction occurs in few patients with pulmonary embolism.¹³ Since the lungs receive oxygen from the airways and have a dual blood supply from the pulmonary and bronchial arteries, they are not particularly vulnerable to ischemia. However, the reported incidence of pulmonary infarction in patients with pulmonary embolism has ranged from 10% to higher than 30%.^5,14,15

The reasons behind pulmonary infarction with complications after pulmonary embolism have varied in different case series in different eras. CT, biopsy, or autopsy studies reveal pulmonary infarction after pulmonary embolism to be more common than suspected by clinical symptoms.

In a Mayo Clinic series of 43 cases of pulmonary infarction diagnosed over a 6-year period by surgical lung biopsy, 18 (42%) of the patients had underlying pulmonary thromboembolism, which was the most common cause.¹⁶

4. Which statement about risk factors for pulmonary infarction in pulmonary embolism is incorrect?

• Heart failure may be a risk factor for pulmonary infarction
• Pulmonary hemorrhage is a risk factor for pulmonary infarction
• Pulmonary infarction is more common with more proximal sites of pulmonary embolism
• Collateral circulation may protect against pulmonary infarction

Infarction is more common with emboli that are distal rather than proximal.

Dalen et al¹⁵ suggested that after pulmonary embolism, pulmonary hemorrhage is an important contributor to the development of pulmonary infarction independent of the presence or absence of associated cardiac or pulmonary disease, but that the effect depends on the site of obstruction.

This idea was first proposed in 1913, when Karsner and Ghoreyeb¹⁷ showed that when pulmonary arteries are completely obstructed, the bronchial arteries take over, except when the embolism is present in a small branch of the pulmonary artery. This is because the physiologic anastomosis between the pulmonary artery and the bronchial arteries is located at the precapillary level of the pulmonary artery, and the bronchial circulation does not take over until the pulmonary arterial pressure in the area of the embolism drops to zero.

Using CT data, Kirchner et al⁵ confirmed that the risk of pulmonary infarction is higher if the obstruction is peripheral, ie, distal.

Using autopsy data, Tsao et al¹⁸ reported a higher risk of pulmonary infarction in embolic occlusion of pulmonary vessels less than 3 mm in diameter.

Collateral circulation has been shown to protect against pulmonary infarction. For example, Miniati et al¹⁴ showed that healthy young patients with pulmonary embolism were more prone to develop pulmonary infarction, probably because they had less efficient collateral systems in the peripheral lung fields. In lung transplant recipients, it has been shown that the risk of infarction decreased with development of collateral circulation.¹⁹

Dalen et al,¹⁵ however, attributed delayed resolution of pulmonary hemorrhage (as measured by resolution of infiltrate on chest radiography) to higher underlying pulmonary venous pressure in patients with heart failure and consequent pulmonary infarction. In comparison, healthy patients without cardiac or pulmonary disease have faster resolution of pulmonary hemorrhage when present, and less likelihood of pulmonary infarction (and death in submassive pulmonary embolism).

Data on the management of infected pulmonary infarction are limited. Mortality rates have been as high as 41% with noninfected and 73% with infected cavitary infarctions.⁴ Some authors have advocated early surgical resection in view of high rates of failure of medical treatment due to lack of blood supply within the cavity and continued risk of infection.

KEY POINTS

In patients with a recently diagnosed pulmonary embolism and concurrent symptoms of bacterial pneumonia, a diagnosis of cavitary pulmonary infarction should be considered.

Consolidations that are pleural-based with sharp, rounded margins and with focal areas of central hyperlucencies representing hemorrhage on the mediastinal windows on CT are more likely to represent a pulmonary infarct.²⁰

A 76-year-old man whose history included abdominal aortic aneurysm repair, bilateral femoral artery bypass for popliteal artery aneurysm, hypertension, and peptic ulcer disease was admitted to a community hospital with pleuritic chest pain and shortness of breath. Two days earlier, he had undergone repair of a ventral hernia.

At the time of that admission, he reported no fever, chills, night sweats, cough, or history of heart or lung disease. His vital signs were normal, and physical examination had revealed no apparent respiratory distress, no jugular venous distention, normal heart sounds, and no pedal edema; however, decreased air entry was noted in the right lung base. Initial serum levels of troponin and N-terminal pro-B-type natriuretic peptide were normal.

At that time, computed tomographic angiography of the chest showed segmental pulmonary emboli in the left upper and right lower lobes of the lungs and right pleural effusion. Transthoracic echocardiography showed normal atrial and ventricular sizes with no right or left ventricular systolic dysfunction and a left ventricular ejection fraction of 59%.

Treatment with intravenous heparin was started, and the patient was transferred to our hospital.

PLEURAL EFFUSION AND PULMONARY EMBOLISM

1. Which of the following is true about pleural effusion?

• It is rarely, if ever, associated with pulmonary embolism
• Most patients with pleural effusion due to pulmonary embolism do not have pleuritic chest pain
• Pulmonary embolism should be excluded in all cases of pleural effusion without a clear cause

Pulmonary embolism should be excluded in all cases of pleural effusion that do not have a clear cause. As for the other answer choices:

• Pulmonary embolism is the fourth leading cause of pleural effusion in the United States, after heart failure, pneumonia, and malignancy.¹
• About 75% of patients who develop pleural effusion in the setting of pulmonary embolism complain of pleuritic chest pain on the side of the effusion.² Most effusions are unilateral, small, and usually exudative.³

EVALUATION BEGINS: RESULTS OF THORACENTESIS

Our patient continued to receive intravenous heparin.

He underwent thoracentesis on hospital day 3, and 1,000 mL of turbid sanguineous pleural fluid was removed. Analysis of the fluid showed pH 7.27, white blood cell count 3.797 × 10⁹/L with 80% neutrophils, and lactate dehydrogenase (LDH) concentration 736 U/L (a ratio of pleural fluid LDH to a concurrent serum LDH > 0.6 is suggestive of an exudate); the fluid was also sent for culture and cytology. Thoracentesis was terminated early due to cough, and follow-up chest radiography showed a moderate-sized pneumothorax.

Computed tomography (CT) of the chest at this time showed a small wedge-shaped area of lung consolidation in the right lower lobe (also seen on CT done 1 day before admission to our hospital), with an intrinsic air-fluid level suggesting a focal infarct or lung abscess, now obscured by adjacent consolidation and atelectasis. In the interval since the previous CT, the multiloculated right pleural effusion had increased in size (Figure 1).

THE NEXT STEP

2. What is the most appropriate next step for this patient?

• Consult an interventional radiologist for chest tube placement
• Start empiric antibiotic therapy and ask an interventional radiologist to place a chest tube
• Start empiric antibiotic therapy, withhold anticoagulation, and consult a thoracic surgeon
• Start empiric antibiotic therapy and consult a thoracic surgeon while continuing anticoagulation

The most appropriate next step is to start empiric antibiotic therapy and consult a thoracic surgeon while continuing anticoagulation.

In this patient, it is appropriate to initiate antibiotics empirically on the basis of his significant pleural loculations, a wedge-shaped consolidation, and 80% neutrophils in the pleural fluid, all of which suggest infection. The unmasking of a wedge-shaped consolidation after thoracentesis, with a previously noted air-fluid level and an interval increase in multiloculated pleural fluid, raises suspicion of a necrotic infection that may have ruptured into the pleural space, a possible lung infarct, or a malignancy. Hence, simply placing a chest tube may not be enough.

Blood in the pleural fluid does not necessitate withholding anticoagulation unless the bleeding is heavy. A pleural fluid hematocrit greater than 50% of the peripheral blood hematocrit suggests hemothorax and is an indication to withhold anticoagulation.¹ Our patient’s pleural fluid was qualitatively sanguineous but not frankly bloody, and therefore we judged that it was not necessary to stop his heparin.

HOW DOES PULMONARY INFARCTION PRESENT CLINICALLY?

3. Which of the following statements about pulmonary infarction is incorrect?

• Cavitation and infarction are more common with larger emboli
• Cavitation occurs in fewer than 10% of pulmonary infarctions
• Lung abscess develops in more than 50% of pulmonary infarctions
• Pulmonary thromboembolism is the most common cause of pulmonary infarction

Lung abscess develops in far fewer than 50% of cases of pulmonary infarction. The rest of the statements are correct.

Cavitation complicates about 4% to 7% of infarctions and is more common when the infarction is 4 cm or greater in diameter.⁴ These cavities are usually single and predominantly on the right side in the apical or posterior segment of the upper lobe or the apical segment of the right lower lobe, as in our patient.^5–8 CT demonstrating scalloped inner margins and cross-cavity band shadows suggests a cavitary pulmonary infarction.^9,10

Infection and abscess in pulmonary infarction are poorly understood but have been linked to larger infarctions, coexistent congestion or atelectasis, and dental or oropharyngeal infection. In an early series of 550 cases of pulmonary infarction, 23 patients (4.2%) developed lung abscess and 6 (1.1%) developed empyema.¹¹ The mean time to cavitation for an infected pulmonary infarction has been reported to be 18 days.¹²

A reversed halo sign, generally described as a focal, rounded area of ground-glass opacity surrounded by a nearly complete ring of consolidation, has been reported to be more frequent with pulmonary infarction than with other diseases, especially when in the lower lobes.¹³

CASE CONTINUED: THORACOSCOPY

A cardiothoracic surgeon was consulted, intravenous heparin was discontinued, an inferior vena cava filter was placed, and the patient underwent video-assisted thoracoscopy.

Purulent fluid was noted on the lateral aspect of right lower lobe; this appeared to be the ruptured cavitary lesion functioning like an uncontrolled bronchopleural fistula. Two chest tubes, sizes 32F and 28F, were placed after decortication, resection of the lung abscess, and closure of the bronchopleural fistula. No significant air leak was noted after resection of this segment of lung.

Pathologic study showed acute organizing pneumonia with abscess formation; no malignant cells or granulomas were seen (Figure 2). Pleural fluid cultures grew Streptococcus intermedius, while the tissue culture was negative for any growth, including acid-fast bacilli and fungi.

On 3 different occasions, both chest tubes were shortened, backed out 2 cm, and resecured with sutures and pins, and Heimlich valves were applied before the patient was discharged.

Intravenous piperacillin-tazobactam was started on the fifth hospital day. On discharge, the patient was advised to continue this treatment for 3 weeks at home.

The patient was receiving enoxaparin subcutaneously in prophylactic doses; 72 hours after the thorascopic procedure this was increased to therapeutic doses, continuing after discharge. Bridging to warfarin was not advised in view of his chest tubes.

Our patient appeared to have developed a right lower lobe infarction that cavitated and ruptured into the pleural space, causing a bronchopleural fistula with empyema after a recent pulmonary embolism. Other reported causes of pulmonary infarction in pulmonary embolism are malignancy and heavy clot burden,⁶ but these have not been confirmed in subsequent studies.⁵ Malignancy was ruled out by biopsy of the resected portion of the lung, and our patient did not have a history of heart failure. A clear cavity was not noted (because it ruptured into the pleura), but an air-fluid level was described in a wedge-shaped consolidation, suggesting infarction.

How common is pulmonary infarction after pulmonary embolism?

Pulmonary infarction occurs in few patients with pulmonary embolism.¹³ Since the lungs receive oxygen from the airways and have a dual blood supply from the pulmonary and bronchial arteries, they are not particularly vulnerable to ischemia. However, the reported incidence of pulmonary infarction in patients with pulmonary embolism has ranged from 10% to higher than 30%.^5,14,15

The reasons behind pulmonary infarction with complications after pulmonary embolism have varied in different case series in different eras. CT, biopsy, or autopsy studies reveal pulmonary infarction after pulmonary embolism to be more common than suspected by clinical symptoms.

In a Mayo Clinic series of 43 cases of pulmonary infarction diagnosed over a 6-year period by surgical lung biopsy, 18 (42%) of the patients had underlying pulmonary thromboembolism, which was the most common cause.¹⁶

4. Which statement about risk factors for pulmonary infarction in pulmonary embolism is incorrect?

• Heart failure may be a risk factor for pulmonary infarction
• Pulmonary hemorrhage is a risk factor for pulmonary infarction
• Pulmonary infarction is more common with more proximal sites of pulmonary embolism
• Collateral circulation may protect against pulmonary infarction

Infarction is more common with emboli that are distal rather than proximal.

Dalen et al¹⁵ suggested that after pulmonary embolism, pulmonary hemorrhage is an important contributor to the development of pulmonary infarction independent of the presence or absence of associated cardiac or pulmonary disease, but that the effect depends on the site of obstruction.

This idea was first proposed in 1913, when Karsner and Ghoreyeb¹⁷ showed that when pulmonary arteries are completely obstructed, the bronchial arteries take over, except when the embolism is present in a small branch of the pulmonary artery. This is because the physiologic anastomosis between the pulmonary artery and the bronchial arteries is located at the precapillary level of the pulmonary artery, and the bronchial circulation does not take over until the pulmonary arterial pressure in the area of the embolism drops to zero.

Using CT data, Kirchner et al⁵ confirmed that the risk of pulmonary infarction is higher if the obstruction is peripheral, ie, distal.

Using autopsy data, Tsao et al¹⁸ reported a higher risk of pulmonary infarction in embolic occlusion of pulmonary vessels less than 3 mm in diameter.

Collateral circulation has been shown to protect against pulmonary infarction. For example, Miniati et al¹⁴ showed that healthy young patients with pulmonary embolism were more prone to develop pulmonary infarction, probably because they had less efficient collateral systems in the peripheral lung fields. In lung transplant recipients, it has been shown that the risk of infarction decreased with development of collateral circulation.¹⁹

Dalen et al,¹⁵ however, attributed delayed resolution of pulmonary hemorrhage (as measured by resolution of infiltrate on chest radiography) to higher underlying pulmonary venous pressure in patients with heart failure and consequent pulmonary infarction. In comparison, healthy patients without cardiac or pulmonary disease have faster resolution of pulmonary hemorrhage when present, and less likelihood of pulmonary infarction (and death in submassive pulmonary embolism).

Data on the management of infected pulmonary infarction are limited. Mortality rates have been as high as 41% with noninfected and 73% with infected cavitary infarctions.⁴ Some authors have advocated early surgical resection in view of high rates of failure of medical treatment due to lack of blood supply within the cavity and continued risk of infection.

KEY POINTS

In patients with a recently diagnosed pulmonary embolism and concurrent symptoms of bacterial pneumonia, a diagnosis of cavitary pulmonary infarction should be considered.

Consolidations that are pleural-based with sharp, rounded margins and with focal areas of central hyperlucencies representing hemorrhage on the mediastinal windows on CT are more likely to represent a pulmonary infarct.²⁰

SAN DIEGO – Acute promyelocytic leukemia is one of five “can’t miss” oncologic emergencies, Megan Boysen Osborn, MD, MHPE, told a standing-room-only crowd at the annual meeting of the American College of Emergency Physicians.

In our exclusive video interview, Dr. Osborn, vice chair of education and the residency program director in the department of emergency medicine at the University of California, Irvine, offered tips on how to recognize acute promyelocytic leukemia, leukostasis, neutropenic fever, tumor lysis syndrome, and disseminated intravascular coagulation.

“All patients with suspected leukemias should be admitted,” she said. “Time is of the essence.”

Dr. Osborn reported having no financial disclosures related to her presentation.

[email protected]

SAN DIEGO – Acute promyelocytic leukemia is one of five “can’t miss” oncologic emergencies, Megan Boysen Osborn, MD, MHPE, told a standing-room-only crowd at the annual meeting of the American College of Emergency Physicians.

In our exclusive video interview, Dr. Osborn, vice chair of education and the residency program director in the department of emergency medicine at the University of California, Irvine, offered tips on how to recognize acute promyelocytic leukemia, leukostasis, neutropenic fever, tumor lysis syndrome, and disseminated intravascular coagulation.

“All patients with suspected leukemias should be admitted,” she said. “Time is of the essence.”

Dr. Osborn reported having no financial disclosures related to her presentation.

[email protected]

SAN DIEGO – Acute promyelocytic leukemia is one of five “can’t miss” oncologic emergencies, Megan Boysen Osborn, MD, MHPE, told a standing-room-only crowd at the annual meeting of the American College of Emergency Physicians.

In our exclusive video interview, Dr. Osborn, vice chair of education and the residency program director in the department of emergency medicine at the University of California, Irvine, offered tips on how to recognize acute promyelocytic leukemia, leukostasis, neutropenic fever, tumor lysis syndrome, and disseminated intravascular coagulation.

“All patients with suspected leukemias should be admitted,” she said. “Time is of the essence.”

Dr. Osborn reported having no financial disclosures related to her presentation.

[email protected]

Study Overview

Objective. To determine if nocturnal dexmedetomidine prevents delirium and improves sleep in critically ill patients.

Design. Two-center, double-blind, placebo-controlled, randomized, trial.

Setting and participants. This study was conducted in the intensive care units (ICU) at 2 centers in North America between 2013 and 2016. Adults admitted to the ICU and receiving intermittent or continuous sedatives and expected to require at least 48 hours of ICU care were included in the study. Exclusion criteria were presence of delirium, severe dementia, acute neurologic injury, severe bradycardia, hepatic encephalopathy, end-stage liver disease, and expected death within 24 hours.

Intervention. Patients were randomized 1:1 to receive nocturnal dexmedetomidine (0.2–0.7 mcg/kg/hr) or dextrose 5% in water. Patients, clinicians, bedside nurses, and all study personnel were blinded to study drug assignment throughout the study. All sedatives were halved before the study drug was administered each evening. As-needed intravenous midazolam was used while titrating up the study drug. Study drug was administered nightly until either ICU discharge or an adverse event occurred. Decisions regarding use of other analgesic and sedative therapy, including opioids, oral benzodiazepines, acetaminophen, and nonsteroidal anti-inflammatory drugs, were left to the discretion of the clinician. Sleep-promoting agents such as melatonin or trazodone were not allowed.

Main outcome measures. The primary outcome was the proportion of patients who remained free of delirium during their critical illness. Secondary outcomes included ICU days spent without delirium; duration of delirium; sleep quality; proportion of patients who ever developed coma; proportion of nocturnal hours spent at each Richmond Agitation and Sedation Scale (RASS) score; maximal nocturnal pain levels; antipsychotic, corticosteroid, and oral analgesic use; days of mechanical ventilation; ICU and hospital stay duration; and ICU and hospital mortality.

Main results. 100 patients were randomized, with 50 patients in each group. 89% of patients were mechanically ventilated, and the Prediction of Delirium in ICU (PRE-DELIRIC) score [1] was 54 in the dexmedetomidine group and 51 in the placebo group. Continuous propofol and fentanyl infusion at randomization was used in 49% and 80%, respectively. Duration of median ICU stay was 10 days in the dexmedetomidine group and 9 days in the placebo group. More patients in the dexmedetomidine group (40 of 50 patients [80%]) than in the placebo group (27 of 50 patients [54%]) remained free of delirium (relative risk [RR], 0.44, 95% confidence interval {CI} 0.23 to 0.82; P = 0.006). The median (interquartile range [IQR]) duration of the first episode of delirium was similar between the dexmedetomidine (IQR 2.0 [0.6–2.7] days) and placebo (2.2 [0.7–3.2] days) groups (P = 0.73). The average Leeds Sleep Evaluation Questionnaire score also was similar (mean difference, 0.02, 95% CI 0.42 to 1.92) between the 2 groups. Incidence of hypotension or bradycardia did not differ significantly between the groups.

Conclusion. Nocturnal administration of low-dose dexmedetomidine in critically ill adults reduces the incidence of delirium during the ICU stay, and patient-reported sleep quality appears unchanged.

Delirium is a sudden state of confusion and/or disturbance of consciousness and cognition that is believed to result from acute brain dysfunction, including neurochemical disequilibrium. It often occurs in association with a general medical condition, such as various types of shock, sepsis, surgery, anesthesia, or electrolyte imbalance. Studies have shown that delirium is associated with increased mortality in critically ill patients [2]. Most ICUs use a systematic assessment tool for early detection of delirium, such as the Confusion Assessment Method for the ICU (CAM-ICU), the Intensive Care Delirium Screening Checklist (ICDSC), or the DSM-IV TR score system. The CAM-ICU is the most frequently used tool to evaluate for the presence of delirium in critically ill patients; it is scored as positive if the patient manifests both an acute change in mental status and inattention, and has either a RASS greater than 0 or disorganized thinking [3].

The level of evidence regarding delirium prevention is low. Ear plugs, eye masks, educational staff, supportive reorientation, and music have been studied as nonpharmacologic methods for preventing delirium [4]. From a pharmacologic standpoint, the dopamine D2 antagonist haloperidol has been explored as a therapy for both treating and preventing delirium, since the condition is thought to be associated with anticholinergic and excessive dopaminergic mechanisms. A randomized controlled study in 142 patients who received haloperidol 2.5 mg intravenously every 8 hours found that the duration of delirium did not differ between the haloperidol and the placebo groups [5]. The most feared adverse effects of haloperidol, such as akathisia, muscle stiffness, arrhythmia, or QT prolongation, did not occur more frequently in the haloperidol group. Similar results have been reported by Al-Qadheeb et al [6]. Pharmacologic prophylaxis of delirium using atypical antipsychotics such as quetiapine has also been explored, but the level of evidence for this intervention remains very low. Current American College of Critical Care Medicine guidelines recommend nonpharmacologic management and do not firmly recommend any pharmacologic prevention for ICU delirium [7].

Dexmedetomidine is a selective alpha-2 adrenergic receptor agonist that acts at the locus ceruleus, providing sedation and analgesia. Studies assessing the choice of sedation in the ICU found that the use of dexmedetomidine or propofol, compared to benzodiazepines, is associated with a lower rate of delirium occurrence, especially in mechanically ventilated patients [8,9]. Dexmedetomidine offers several potential advantages over other sedative drugs: it has little effect on cognition, has minimal anticholinergic effect, and may restore a natural sleep pattern. While propofol causes hypotension, respiratory depression, and deeper sedation, dexmedetomidine is associated with lighter sedation, a minimal effect on respiratory drive, and a milder hemodynamic effect. In a randomized controlled trial involving post-surgery ICU patients, dexmedetomidine partially restored a normal sleep pattern (eg, increased percentage of stage 2 non-rapid eye movement sleep), prolonged total sleep time, improved sleep efficiency, and increased sleep quality [10]; by improving overall sleep quality, dexmedetomidine potentially may prevent delirium. Another study that randomly assigned 700 ICU patients who underwent noncardiac surgery to dexmedetomidine infusion (0.1 mcg/kg/hr from ICU admission on the day of surgery until the following morning) or placebo reported a significantly reduced incidence of delirium in the dexmedetomidine group [11]. On the other hand, a 2015 Cochrane meta-analysis that included 7 randomized controlled studies did not find a significant risk reduction of delirium with dexmedetomidine [12].

The current study by Skrobik et al was a randomized, placebo-controlled trial that examined the role of nocturnal dexmedetomidine in ICU delirium prevention in 100 ICU patients. Nocturnal administration of low-dose dexmedetomidine led to a statistically significant reduction in delirium incidence compared to placebo (RR of delirium, 0.44, 95% CI 0.23 to 0.82, which is similar to that suggested by previous studies). This study adds additional evidence regarding the use of dexmedetomidine for pharmacologic delirium prevention. It included many mechanically ventilated patients (89% of study population), strengthening the applicability of the result. Mechanical ventilation is a known risk factor for ICU delirium, and therefore this is an important population to study; previous trials largely included patients who were not mechanically ventilated. This study also supports the safety of dexmedetomidine infusion, especially in lower doses in critically ill patients, without significantly increasing the incidence of adverse events (mainly hypotension and bradycardia). The study protocol closely approximated real practice by allowing other analgesics, including opioids, and therefore suggests safety and real world applicability.

There are several confounding issues in this study. The study was blinded, and there was concern that the bedside nurses may have been able to identify the study drug based on the effects on heart rate. In addition, 50% of patients received antipsychotics. While baseline RASS score was significantly different between the 2 groups, patients in the dexmedetomidine group reached a deeper level of sedation during the study. Also, the protocol mandated halving the pre-existing sedative on the night of study drug initiation, which could have led to inadequate sedation in the placebo group. Placebo patients received propofol for a similar duration but at a higher dose compared to dexmedetomidine patients, and midazolam and fentanyl infusion was used in a similar pattern between the groups. The high exclusion rate (71%) limits the ability to generalize the results to all ICU patients.

Applications for Clinical Practice

ICU delirium is an important complication of critical illness and is potentially preventable. Benzodiazepines are associated with an increased risk of delirium, while there has been increasing interest in dexmedetomidine, a selective alpha-2 adrenergic receptor agonist, because of its potential for delirium prevention. Evidence to date does not strongly support routine use of pharmacologic prevention of delirium; however, dexmedetomidine may be an option for sedation, as opposed to benzodiazepines or propofol, in selected patients and may potentially prevent delirium.

—Minkyung Kwon, MD, Neal Patel, MD, and Vichaya Arunthari, MD, Pulmonary and Critical Care Medicine, Mayo Clinic Florida, Jacksonville, FL

Study Overview

Objective. To determine if nocturnal dexmedetomidine prevents delirium and improves sleep in critically ill patients.

Design. Two-center, double-blind, placebo-controlled, randomized, trial.

Setting and participants. This study was conducted in the intensive care units (ICU) at 2 centers in North America between 2013 and 2016. Adults admitted to the ICU and receiving intermittent or continuous sedatives and expected to require at least 48 hours of ICU care were included in the study. Exclusion criteria were presence of delirium, severe dementia, acute neurologic injury, severe bradycardia, hepatic encephalopathy, end-stage liver disease, and expected death within 24 hours.

Intervention. Patients were randomized 1:1 to receive nocturnal dexmedetomidine (0.2–0.7 mcg/kg/hr) or dextrose 5% in water. Patients, clinicians, bedside nurses, and all study personnel were blinded to study drug assignment throughout the study. All sedatives were halved before the study drug was administered each evening. As-needed intravenous midazolam was used while titrating up the study drug. Study drug was administered nightly until either ICU discharge or an adverse event occurred. Decisions regarding use of other analgesic and sedative therapy, including opioids, oral benzodiazepines, acetaminophen, and nonsteroidal anti-inflammatory drugs, were left to the discretion of the clinician. Sleep-promoting agents such as melatonin or trazodone were not allowed.

Main outcome measures. The primary outcome was the proportion of patients who remained free of delirium during their critical illness. Secondary outcomes included ICU days spent without delirium; duration of delirium; sleep quality; proportion of patients who ever developed coma; proportion of nocturnal hours spent at each Richmond Agitation and Sedation Scale (RASS) score; maximal nocturnal pain levels; antipsychotic, corticosteroid, and oral analgesic use; days of mechanical ventilation; ICU and hospital stay duration; and ICU and hospital mortality.

Main results. 100 patients were randomized, with 50 patients in each group. 89% of patients were mechanically ventilated, and the Prediction of Delirium in ICU (PRE-DELIRIC) score [1] was 54 in the dexmedetomidine group and 51 in the placebo group. Continuous propofol and fentanyl infusion at randomization was used in 49% and 80%, respectively. Duration of median ICU stay was 10 days in the dexmedetomidine group and 9 days in the placebo group. More patients in the dexmedetomidine group (40 of 50 patients [80%]) than in the placebo group (27 of 50 patients [54%]) remained free of delirium (relative risk [RR], 0.44, 95% confidence interval {CI} 0.23 to 0.82; P = 0.006). The median (interquartile range [IQR]) duration of the first episode of delirium was similar between the dexmedetomidine (IQR 2.0 [0.6–2.7] days) and placebo (2.2 [0.7–3.2] days) groups (P = 0.73). The average Leeds Sleep Evaluation Questionnaire score also was similar (mean difference, 0.02, 95% CI 0.42 to 1.92) between the 2 groups. Incidence of hypotension or bradycardia did not differ significantly between the groups.

Conclusion. Nocturnal administration of low-dose dexmedetomidine in critically ill adults reduces the incidence of delirium during the ICU stay, and patient-reported sleep quality appears unchanged.

Delirium is a sudden state of confusion and/or disturbance of consciousness and cognition that is believed to result from acute brain dysfunction, including neurochemical disequilibrium. It often occurs in association with a general medical condition, such as various types of shock, sepsis, surgery, anesthesia, or electrolyte imbalance. Studies have shown that delirium is associated with increased mortality in critically ill patients [2]. Most ICUs use a systematic assessment tool for early detection of delirium, such as the Confusion Assessment Method for the ICU (CAM-ICU), the Intensive Care Delirium Screening Checklist (ICDSC), or the DSM-IV TR score system. The CAM-ICU is the most frequently used tool to evaluate for the presence of delirium in critically ill patients; it is scored as positive if the patient manifests both an acute change in mental status and inattention, and has either a RASS greater than 0 or disorganized thinking [3].

The level of evidence regarding delirium prevention is low. Ear plugs, eye masks, educational staff, supportive reorientation, and music have been studied as nonpharmacologic methods for preventing delirium [4]. From a pharmacologic standpoint, the dopamine D2 antagonist haloperidol has been explored as a therapy for both treating and preventing delirium, since the condition is thought to be associated with anticholinergic and excessive dopaminergic mechanisms. A randomized controlled study in 142 patients who received haloperidol 2.5 mg intravenously every 8 hours found that the duration of delirium did not differ between the haloperidol and the placebo groups [5]. The most feared adverse effects of haloperidol, such as akathisia, muscle stiffness, arrhythmia, or QT prolongation, did not occur more frequently in the haloperidol group. Similar results have been reported by Al-Qadheeb et al [6]. Pharmacologic prophylaxis of delirium using atypical antipsychotics such as quetiapine has also been explored, but the level of evidence for this intervention remains very low. Current American College of Critical Care Medicine guidelines recommend nonpharmacologic management and do not firmly recommend any pharmacologic prevention for ICU delirium [7].

Dexmedetomidine is a selective alpha-2 adrenergic receptor agonist that acts at the locus ceruleus, providing sedation and analgesia. Studies assessing the choice of sedation in the ICU found that the use of dexmedetomidine or propofol, compared to benzodiazepines, is associated with a lower rate of delirium occurrence, especially in mechanically ventilated patients [8,9]. Dexmedetomidine offers several potential advantages over other sedative drugs: it has little effect on cognition, has minimal anticholinergic effect, and may restore a natural sleep pattern. While propofol causes hypotension, respiratory depression, and deeper sedation, dexmedetomidine is associated with lighter sedation, a minimal effect on respiratory drive, and a milder hemodynamic effect. In a randomized controlled trial involving post-surgery ICU patients, dexmedetomidine partially restored a normal sleep pattern (eg, increased percentage of stage 2 non-rapid eye movement sleep), prolonged total sleep time, improved sleep efficiency, and increased sleep quality [10]; by improving overall sleep quality, dexmedetomidine potentially may prevent delirium. Another study that randomly assigned 700 ICU patients who underwent noncardiac surgery to dexmedetomidine infusion (0.1 mcg/kg/hr from ICU admission on the day of surgery until the following morning) or placebo reported a significantly reduced incidence of delirium in the dexmedetomidine group [11]. On the other hand, a 2015 Cochrane meta-analysis that included 7 randomized controlled studies did not find a significant risk reduction of delirium with dexmedetomidine [12].

The current study by Skrobik et al was a randomized, placebo-controlled trial that examined the role of nocturnal dexmedetomidine in ICU delirium prevention in 100 ICU patients. Nocturnal administration of low-dose dexmedetomidine led to a statistically significant reduction in delirium incidence compared to placebo (RR of delirium, 0.44, 95% CI 0.23 to 0.82, which is similar to that suggested by previous studies). This study adds additional evidence regarding the use of dexmedetomidine for pharmacologic delirium prevention. It included many mechanically ventilated patients (89% of study population), strengthening the applicability of the result. Mechanical ventilation is a known risk factor for ICU delirium, and therefore this is an important population to study; previous trials largely included patients who were not mechanically ventilated. This study also supports the safety of dexmedetomidine infusion, especially in lower doses in critically ill patients, without significantly increasing the incidence of adverse events (mainly hypotension and bradycardia). The study protocol closely approximated real practice by allowing other analgesics, including opioids, and therefore suggests safety and real world applicability.

There are several confounding issues in this study. The study was blinded, and there was concern that the bedside nurses may have been able to identify the study drug based on the effects on heart rate. In addition, 50% of patients received antipsychotics. While baseline RASS score was significantly different between the 2 groups, patients in the dexmedetomidine group reached a deeper level of sedation during the study. Also, the protocol mandated halving the pre-existing sedative on the night of study drug initiation, which could have led to inadequate sedation in the placebo group. Placebo patients received propofol for a similar duration but at a higher dose compared to dexmedetomidine patients, and midazolam and fentanyl infusion was used in a similar pattern between the groups. The high exclusion rate (71%) limits the ability to generalize the results to all ICU patients.

Applications for Clinical Practice

ICU delirium is an important complication of critical illness and is potentially preventable. Benzodiazepines are associated with an increased risk of delirium, while there has been increasing interest in dexmedetomidine, a selective alpha-2 adrenergic receptor agonist, because of its potential for delirium prevention. Evidence to date does not strongly support routine use of pharmacologic prevention of delirium; however, dexmedetomidine may be an option for sedation, as opposed to benzodiazepines or propofol, in selected patients and may potentially prevent delirium.

—Minkyung Kwon, MD, Neal Patel, MD, and Vichaya Arunthari, MD, Pulmonary and Critical Care Medicine, Mayo Clinic Florida, Jacksonville, FL

Study Overview

Objective. To determine if nocturnal dexmedetomidine prevents delirium and improves sleep in critically ill patients.

Design. Two-center, double-blind, placebo-controlled, randomized, trial.

Setting and participants. This study was conducted in the intensive care units (ICU) at 2 centers in North America between 2013 and 2016. Adults admitted to the ICU and receiving intermittent or continuous sedatives and expected to require at least 48 hours of ICU care were included in the study. Exclusion criteria were presence of delirium, severe dementia, acute neurologic injury, severe bradycardia, hepatic encephalopathy, end-stage liver disease, and expected death within 24 hours.

Intervention. Patients were randomized 1:1 to receive nocturnal dexmedetomidine (0.2–0.7 mcg/kg/hr) or dextrose 5% in water. Patients, clinicians, bedside nurses, and all study personnel were blinded to study drug assignment throughout the study. All sedatives were halved before the study drug was administered each evening. As-needed intravenous midazolam was used while titrating up the study drug. Study drug was administered nightly until either ICU discharge or an adverse event occurred. Decisions regarding use of other analgesic and sedative therapy, including opioids, oral benzodiazepines, acetaminophen, and nonsteroidal anti-inflammatory drugs, were left to the discretion of the clinician. Sleep-promoting agents such as melatonin or trazodone were not allowed.

Main outcome measures. The primary outcome was the proportion of patients who remained free of delirium during their critical illness. Secondary outcomes included ICU days spent without delirium; duration of delirium; sleep quality; proportion of patients who ever developed coma; proportion of nocturnal hours spent at each Richmond Agitation and Sedation Scale (RASS) score; maximal nocturnal pain levels; antipsychotic, corticosteroid, and oral analgesic use; days of mechanical ventilation; ICU and hospital stay duration; and ICU and hospital mortality.

Main results. 100 patients were randomized, with 50 patients in each group. 89% of patients were mechanically ventilated, and the Prediction of Delirium in ICU (PRE-DELIRIC) score [1] was 54 in the dexmedetomidine group and 51 in the placebo group. Continuous propofol and fentanyl infusion at randomization was used in 49% and 80%, respectively. Duration of median ICU stay was 10 days in the dexmedetomidine group and 9 days in the placebo group. More patients in the dexmedetomidine group (40 of 50 patients [80%]) than in the placebo group (27 of 50 patients [54%]) remained free of delirium (relative risk [RR], 0.44, 95% confidence interval {CI} 0.23 to 0.82; P = 0.006). The median (interquartile range [IQR]) duration of the first episode of delirium was similar between the dexmedetomidine (IQR 2.0 [0.6–2.7] days) and placebo (2.2 [0.7–3.2] days) groups (P = 0.73). The average Leeds Sleep Evaluation Questionnaire score also was similar (mean difference, 0.02, 95% CI 0.42 to 1.92) between the 2 groups. Incidence of hypotension or bradycardia did not differ significantly between the groups.

Conclusion. Nocturnal administration of low-dose dexmedetomidine in critically ill adults reduces the incidence of delirium during the ICU stay, and patient-reported sleep quality appears unchanged.

Delirium is a sudden state of confusion and/or disturbance of consciousness and cognition that is believed to result from acute brain dysfunction, including neurochemical disequilibrium. It often occurs in association with a general medical condition, such as various types of shock, sepsis, surgery, anesthesia, or electrolyte imbalance. Studies have shown that delirium is associated with increased mortality in critically ill patients [2]. Most ICUs use a systematic assessment tool for early detection of delirium, such as the Confusion Assessment Method for the ICU (CAM-ICU), the Intensive Care Delirium Screening Checklist (ICDSC), or the DSM-IV TR score system. The CAM-ICU is the most frequently used tool to evaluate for the presence of delirium in critically ill patients; it is scored as positive if the patient manifests both an acute change in mental status and inattention, and has either a RASS greater than 0 or disorganized thinking [3].

The level of evidence regarding delirium prevention is low. Ear plugs, eye masks, educational staff, supportive reorientation, and music have been studied as nonpharmacologic methods for preventing delirium [4]. From a pharmacologic standpoint, the dopamine D2 antagonist haloperidol has been explored as a therapy for both treating and preventing delirium, since the condition is thought to be associated with anticholinergic and excessive dopaminergic mechanisms. A randomized controlled study in 142 patients who received haloperidol 2.5 mg intravenously every 8 hours found that the duration of delirium did not differ between the haloperidol and the placebo groups [5]. The most feared adverse effects of haloperidol, such as akathisia, muscle stiffness, arrhythmia, or QT prolongation, did not occur more frequently in the haloperidol group. Similar results have been reported by Al-Qadheeb et al [6]. Pharmacologic prophylaxis of delirium using atypical antipsychotics such as quetiapine has also been explored, but the level of evidence for this intervention remains very low. Current American College of Critical Care Medicine guidelines recommend nonpharmacologic management and do not firmly recommend any pharmacologic prevention for ICU delirium [7].

Dexmedetomidine is a selective alpha-2 adrenergic receptor agonist that acts at the locus ceruleus, providing sedation and analgesia. Studies assessing the choice of sedation in the ICU found that the use of dexmedetomidine or propofol, compared to benzodiazepines, is associated with a lower rate of delirium occurrence, especially in mechanically ventilated patients [8,9]. Dexmedetomidine offers several potential advantages over other sedative drugs: it has little effect on cognition, has minimal anticholinergic effect, and may restore a natural sleep pattern. While propofol causes hypotension, respiratory depression, and deeper sedation, dexmedetomidine is associated with lighter sedation, a minimal effect on respiratory drive, and a milder hemodynamic effect. In a randomized controlled trial involving post-surgery ICU patients, dexmedetomidine partially restored a normal sleep pattern (eg, increased percentage of stage 2 non-rapid eye movement sleep), prolonged total sleep time, improved sleep efficiency, and increased sleep quality [10]; by improving overall sleep quality, dexmedetomidine potentially may prevent delirium. Another study that randomly assigned 700 ICU patients who underwent noncardiac surgery to dexmedetomidine infusion (0.1 mcg/kg/hr from ICU admission on the day of surgery until the following morning) or placebo reported a significantly reduced incidence of delirium in the dexmedetomidine group [11]. On the other hand, a 2015 Cochrane meta-analysis that included 7 randomized controlled studies did not find a significant risk reduction of delirium with dexmedetomidine [12].

The current study by Skrobik et al was a randomized, placebo-controlled trial that examined the role of nocturnal dexmedetomidine in ICU delirium prevention in 100 ICU patients. Nocturnal administration of low-dose dexmedetomidine led to a statistically significant reduction in delirium incidence compared to placebo (RR of delirium, 0.44, 95% CI 0.23 to 0.82, which is similar to that suggested by previous studies). This study adds additional evidence regarding the use of dexmedetomidine for pharmacologic delirium prevention. It included many mechanically ventilated patients (89% of study population), strengthening the applicability of the result. Mechanical ventilation is a known risk factor for ICU delirium, and therefore this is an important population to study; previous trials largely included patients who were not mechanically ventilated. This study also supports the safety of dexmedetomidine infusion, especially in lower doses in critically ill patients, without significantly increasing the incidence of adverse events (mainly hypotension and bradycardia). The study protocol closely approximated real practice by allowing other analgesics, including opioids, and therefore suggests safety and real world applicability.

There are several confounding issues in this study. The study was blinded, and there was concern that the bedside nurses may have been able to identify the study drug based on the effects on heart rate. In addition, 50% of patients received antipsychotics. While baseline RASS score was significantly different between the 2 groups, patients in the dexmedetomidine group reached a deeper level of sedation during the study. Also, the protocol mandated halving the pre-existing sedative on the night of study drug initiation, which could have led to inadequate sedation in the placebo group. Placebo patients received propofol for a similar duration but at a higher dose compared to dexmedetomidine patients, and midazolam and fentanyl infusion was used in a similar pattern between the groups. The high exclusion rate (71%) limits the ability to generalize the results to all ICU patients.

Applications for Clinical Practice

ICU delirium is an important complication of critical illness and is potentially preventable. Benzodiazepines are associated with an increased risk of delirium, while there has been increasing interest in dexmedetomidine, a selective alpha-2 adrenergic receptor agonist, because of its potential for delirium prevention. Evidence to date does not strongly support routine use of pharmacologic prevention of delirium; however, dexmedetomidine may be an option for sedation, as opposed to benzodiazepines or propofol, in selected patients and may potentially prevent delirium.

—Minkyung Kwon, MD, Neal Patel, MD, and Vichaya Arunthari, MD, Pulmonary and Critical Care Medicine, Mayo Clinic Florida, Jacksonville, FL

An 88-year-old man with a 1-day history of fever and altered mental status was transferred to the emergency department. He had been receiving conservative management for low-risk localized prostate cancer but had no previous cardiovascular or gastrointestinal problems.

Based on these findings, the diagnosis was Fournier gangrene. Despite aggressive treatment, the patient’s condition deteriorated rapidly, and he died 2 hours after admission.

FOURNIER GANGRENE: NECROTIZING FASCIITIS OF THE PERINEUM

Fournier gangrene is a rare but rapidly progressive necrotizing fasciitis of the perineum with a high death rate.

Predisposing factors for Fournier gangrene include older age, diabetes mellitus, morbid obesity, cardiovascular disorders, chronic alcoholism, long-term corticosteroid treatment, malignancy, and human immunodeficiency virus infection.^1,2 Urethral obstruction, instrumentation, urinary extravasation, and trauma have also been associated with this condition.³

In general, organisms from the urinary tract spread along the fascial planes to involve the penis and scrotum.

The differential diagnosis of Fournier gangrene includes scrotal and perineal disorders, as well as intra-abdominal disorders such as cellulitis, abscess, strangulated hernia, pyoderma gangrenosum, allergic vasculitis, vascular occlusion syndromes, and warfarin necrosis.

Delay in the diagnosis of Fournier gangrene leads to an extremely high death rate due to rapid progression of the disease, leading to sepsis, multiple organ failure, and disseminated intravascular coagulation. Immediate diagnosis and appropriate treatment such as broad-spectrum antibiotics and extensive surgical debridement reduce morbidity and control the infection. Antibiotics for methicillin-resistant Staphylococcus aureus should be considered if there is a history of or risk factors for this organism.⁴

Necrotizing fasciitis, including Fournier gangrene, is a common indication for intravenous immunoglobulin, and this treatment has been reported to be effective in a few cases. However, a double-blind, placebo-controlled trial that evaluated the benefit of this treatment was terminated early due to slow patient recruitment.⁵

A delay of even a few hours from suspicion of Fournier gangrene to surgical debridement significantly increases the risk of death.⁶ Thus, when it is suspected, immediate surgical intervention may be necessary to confirm the diagnosis and to treat it. The usual combination of antibiotic therapy for Fournier gangrene includes penicillin for the streptococcal species, a third-generation cephalosporin with or without an aminoglycoside for the gram-negative organisms, and metronidazole for anaerobic bacteria.

An 88-year-old man with a 1-day history of fever and altered mental status was transferred to the emergency department. He had been receiving conservative management for low-risk localized prostate cancer but had no previous cardiovascular or gastrointestinal problems.

Based on these findings, the diagnosis was Fournier gangrene. Despite aggressive treatment, the patient’s condition deteriorated rapidly, and he died 2 hours after admission.

FOURNIER GANGRENE: NECROTIZING FASCIITIS OF THE PERINEUM

Fournier gangrene is a rare but rapidly progressive necrotizing fasciitis of the perineum with a high death rate.

Predisposing factors for Fournier gangrene include older age, diabetes mellitus, morbid obesity, cardiovascular disorders, chronic alcoholism, long-term corticosteroid treatment, malignancy, and human immunodeficiency virus infection.^1,2 Urethral obstruction, instrumentation, urinary extravasation, and trauma have also been associated with this condition.³

In general, organisms from the urinary tract spread along the fascial planes to involve the penis and scrotum.

The differential diagnosis of Fournier gangrene includes scrotal and perineal disorders, as well as intra-abdominal disorders such as cellulitis, abscess, strangulated hernia, pyoderma gangrenosum, allergic vasculitis, vascular occlusion syndromes, and warfarin necrosis.

Delay in the diagnosis of Fournier gangrene leads to an extremely high death rate due to rapid progression of the disease, leading to sepsis, multiple organ failure, and disseminated intravascular coagulation. Immediate diagnosis and appropriate treatment such as broad-spectrum antibiotics and extensive surgical debridement reduce morbidity and control the infection. Antibiotics for methicillin-resistant Staphylococcus aureus should be considered if there is a history of or risk factors for this organism.⁴

Necrotizing fasciitis, including Fournier gangrene, is a common indication for intravenous immunoglobulin, and this treatment has been reported to be effective in a few cases. However, a double-blind, placebo-controlled trial that evaluated the benefit of this treatment was terminated early due to slow patient recruitment.⁵

A delay of even a few hours from suspicion of Fournier gangrene to surgical debridement significantly increases the risk of death.⁶ Thus, when it is suspected, immediate surgical intervention may be necessary to confirm the diagnosis and to treat it. The usual combination of antibiotic therapy for Fournier gangrene includes penicillin for the streptococcal species, a third-generation cephalosporin with or without an aminoglycoside for the gram-negative organisms, and metronidazole for anaerobic bacteria.

An 88-year-old man with a 1-day history of fever and altered mental status was transferred to the emergency department. He had been receiving conservative management for low-risk localized prostate cancer but had no previous cardiovascular or gastrointestinal problems.

Based on these findings, the diagnosis was Fournier gangrene. Despite aggressive treatment, the patient’s condition deteriorated rapidly, and he died 2 hours after admission.

FOURNIER GANGRENE: NECROTIZING FASCIITIS OF THE PERINEUM

Fournier gangrene is a rare but rapidly progressive necrotizing fasciitis of the perineum with a high death rate.

Predisposing factors for Fournier gangrene include older age, diabetes mellitus, morbid obesity, cardiovascular disorders, chronic alcoholism, long-term corticosteroid treatment, malignancy, and human immunodeficiency virus infection.^1,2 Urethral obstruction, instrumentation, urinary extravasation, and trauma have also been associated with this condition.³

In general, organisms from the urinary tract spread along the fascial planes to involve the penis and scrotum.

The differential diagnosis of Fournier gangrene includes scrotal and perineal disorders, as well as intra-abdominal disorders such as cellulitis, abscess, strangulated hernia, pyoderma gangrenosum, allergic vasculitis, vascular occlusion syndromes, and warfarin necrosis.

Delay in the diagnosis of Fournier gangrene leads to an extremely high death rate due to rapid progression of the disease, leading to sepsis, multiple organ failure, and disseminated intravascular coagulation. Immediate diagnosis and appropriate treatment such as broad-spectrum antibiotics and extensive surgical debridement reduce morbidity and control the infection. Antibiotics for methicillin-resistant Staphylococcus aureus should be considered if there is a history of or risk factors for this organism.⁴

Necrotizing fasciitis, including Fournier gangrene, is a common indication for intravenous immunoglobulin, and this treatment has been reported to be effective in a few cases. However, a double-blind, placebo-controlled trial that evaluated the benefit of this treatment was terminated early due to slow patient recruitment.⁵

A delay of even a few hours from suspicion of Fournier gangrene to surgical debridement significantly increases the risk of death.⁶ Thus, when it is suspected, immediate surgical intervention may be necessary to confirm the diagnosis and to treat it. The usual combination of antibiotic therapy for Fournier gangrene includes penicillin for the streptococcal species, a third-generation cephalosporin with or without an aminoglycoside for the gram-negative organisms, and metronidazole for anaerobic bacteria.