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Must-read acute care medicine articles from 2022
When 2022 began, we started seeing some light at the end of the COVID-19 tunnel. Vaccines were widely available, and even with new variants of the virus still occasionally emerging, the rates of severe morbidity and mortality appeared to be decreasing.
Expectedly, journals appeared to start moving more toward mainstream topics and publications rather than what seemed like a major focus on COVID-19 publications. The resulting literature was fantastic.
Several of those topics were discussed in a prior Emergency Medicine Viewpoint from this news organization, and many more of the research advances of 2022 will be discussed in the near future. However, in this Viewpoint, I would like to present my annual review of my three “must-read” articles of the past year.
As in past years, I am choosing reviews of the literature rather than original research articles (which, all too often, become outdated or debunked within a few years). I choose these articles in the hopes that readers will not simply settle for my brief reviews of the key points but instead will feel compelled to download and read the entire articles. These publications address common conditions and quandaries we face in the daily practice of emergency medicine and are practice-changing.
Myocardial dysfunction after cardiac arrest: Tips and pitfalls
The management of post–cardiac arrest patients remains a hot topic in the resuscitation literature as we continue to understand that the immediate post-arrest period is critical to patient outcome.
Ortuno and colleagues reviewed the current literature on post-arrest care and wrote an outstanding summary of how to optimally care for these patients. More specifically, they focused on post-arrest patients who demonstrate continued shock, or “post–cardiac arrest myocardial dysfunction” (PCAMD).
They propose three mechanisms for the pathogenesis of PCAMD: ischemia reperfusion phenomenon, systemic inflammatory response, and increased catecholamine release
I will skip through the details of the pathophysiology that they describe in the article, but I certainly do recommend that everyone review their descriptions.
Management of these patients begins with a good hemodynamic assessment, which includes clinical markers of perfusion (blood pressure, capillary refill), ECG, and point-of-care ultrasound (POCUS). If the initial assessment reveals an obvious cause of the cardiac arrest (e.g., massive pulmonary embolism, myocardial infarction, pericardial tamponade), then the underlying cause should be treated expeditiously.
In the absence of an obvious treatable cause of the shock, the fluid status and cardiac function should be addressed with POCUS. If the patient is hypovolemic, intravenous fluids should be administered. If the fluid status is adequate, POCUS should be used to estimate the patient’s ventricular function. If the ventricle appears to be hyperdynamic with good contractility, shock should be treated with norepinephrine. On the other hand, if the ventricle is hypodynamic, dobutamine should be substituted for norepinephrine or, more often, added to norepinephrine.
The above represents a simplified summary of the critical points, but the authors do delve into further detail and also discuss some other options for therapies, including steroids, coronary revascularization, extracorporeal membrane oxygenation, and so on. The review is very thoughtful, thorough, and definitely worth a full read.
Top myths of diagnosis and management of infectious diseases in hospital medicine
Most, if not all of us in medicine, have heard the saying that 50% of what we learn in medical school (or residency) will turn out to be wrong. I certainly believe in this concept and consequently, like many of you, I enjoy reading about myths and misconceptions that we have been taught. With that in mind, I have to say that I love this article because it seems to have been written specifically to address what I was taught!
This author group, consisting mostly of clinical PharmDs who are experts in antibiotic use, provide us with an evidence-based discussion of myths and pitfalls in how antibiotics are often used in current clinical practice. The authors review their top 10 myths involving the use of antibiotics in treating infections in the hospital setting. A few of these relate more to the inpatient setting, but here are my favorite emergency department (ED)–related myths that they address:
- “Antibiotics do no harm.” The authors address the risk-benefit of antibiotics based on assumed vs. confirmed infections, including a brief discussion of adverse drug effects.
- “Antibiotic durations of 7, 14, or 21 days are typically necessary.” The authors address appropriate duration of antibiotic use and the fact that unnecessarily long durations of use can lead to resistance. They also provide reassurance that some infections can be treated with quite short durations of antibiotics.
- “If one drug is good, two (or more!) is better.” The use of multiple antibiotics, often with overlapping bacterial coverage, is rampant in medicine and further increases the risk for adverse drug effects and resistance.
- “Oral antibiotics are not as good as intravenous antibiotics for hospitalized patients.” This is definitely a myth that I learned. I recall being taught by many senior physicians that anyone sick enough for admission should be treated with intravenous antibiotics. As it turns out, absorption and effectiveness of most oral antibiotics is just as good as intravenous antibiotics, and the oral formulations are often safer.
- “A history of a penicillin allergy means the patient can never receive a beta-lactam antibiotic.” This is a myth that was debunked quite a few years ago, but it seems that many clinicians still need a reminder.
The authors included five more myths that are worth the read. This is an article that needs to be disseminated among all hospital clinicians.
Guidelines for low-risk, recurrent abdominal pain in the emergency department
The Society for Academic Emergency Medicine (SAEM) recently initiated a program focused on creating evidence-based approaches to challenging chief complaints and presentations in the emergency department (ED). In 2021, they published an approach to managing patients with recurrent, low-risk chest pain in the ED. This past year, they published their second guideline, focused on the management of patients with low-risk, recurrent abdominal pain in the ED.
Recurrent low-risk abdominal pain is a common and vexing presentation to EDs around the world, and there is little prior published guidance. Do all of these patients need repeat imaging? How do we manage their pain? Are there nonabdominal conditions that should be considered?
Broder and colleagues did a fantastic review of the current literature and, on behalf of SAEM, have provided a rational approach to optimal management of these patients. The four major questions they addressed, with brief summaries of their recommendations, are:
- Should adult ED patients with low-risk, recurrent and previously undifferentiated abdominal pain receive a repeat CT abdomen-pelvis (CTAP) after a negative CTAP within the past 12 months? This is a typical question that we all ponder when managing these patients. Unfortunately, the writing group found insufficient evidence to definitively identify populations in whom CTAP was recommended vs could be safely withheld. It is a bit disappointing that there is no definite answer to the question. On the other hand, it is reassuring to know that the world’s best evidence essentially says that it is perfectly appropriate to use your own good clinical judgment.
- Should adult ED patients with low-risk, recurrent, and previously undifferentiated abdominal pain with a negative CTAP receive additional imaging with abdominal ultrasound? In this case, the writing group found enough evidence, though low-level, to suggest against routine ultrasound in the absence of concern specifically for pelvic or hepatobiliary pathology. Like most tests, ultrasound is best used when there are specific concerns rather than being used in an undifferentiated fashion.
- Should adult ED patients with low-risk, recurrent, and previously undifferentiated abdominal pain receive screening for depression/anxiety? The writing group found enough evidence, though low-level again, to suggest that screening for depression and/or anxiety be performed during the ED evaluation. This could lead to successful therapy for the abdominal pain.
- Should adult ED patients with low-risk, recurrent, and previously undifferentiated abdominal pain receive nonopioid and/or nonpharmacologic analgesics? The writing group found little evidence to suggest for or against these analgesics, but they made a consensus recommendation suggesting an opioid-minimizing strategy for pain control.
Although the final recommendations of the writing group were not definitive or based on the strongest level of evidence, I find it helpful to have this guidance, nevertheless, on behalf of a major national organization. I also find it helpful to know that even with the best evidence available, optimal patient care will often boil down to physician experience and gestalt. I should also add that the overall article is chock-full of pearls and helpful information that will further inform the readers’ decisions, and so the full version is definitely worth the read.
In summary
There you have it – my three favorite practice-changing articles of 2022. Although I have tried to provide key points here, the full discussions of those key points in the published articles will provide a great deal more education than I can offer in this brief write-up, and so I strongly encourage everyone to read the full versions. Please be sure to include in the comments section your own pick for favorite or must-read articles from the past year.
Amal Mattu, MD, is a professor, vice chair of education, and codirector of the emergency cardiology fellowship in the department of emergency medicine at the University of Maryland, Baltimore. She reported no relevant conflicts of interest.
A version of this article first appeared on Medscape.com.
When 2022 began, we started seeing some light at the end of the COVID-19 tunnel. Vaccines were widely available, and even with new variants of the virus still occasionally emerging, the rates of severe morbidity and mortality appeared to be decreasing.
Expectedly, journals appeared to start moving more toward mainstream topics and publications rather than what seemed like a major focus on COVID-19 publications. The resulting literature was fantastic.
Several of those topics were discussed in a prior Emergency Medicine Viewpoint from this news organization, and many more of the research advances of 2022 will be discussed in the near future. However, in this Viewpoint, I would like to present my annual review of my three “must-read” articles of the past year.
As in past years, I am choosing reviews of the literature rather than original research articles (which, all too often, become outdated or debunked within a few years). I choose these articles in the hopes that readers will not simply settle for my brief reviews of the key points but instead will feel compelled to download and read the entire articles. These publications address common conditions and quandaries we face in the daily practice of emergency medicine and are practice-changing.
Myocardial dysfunction after cardiac arrest: Tips and pitfalls
The management of post–cardiac arrest patients remains a hot topic in the resuscitation literature as we continue to understand that the immediate post-arrest period is critical to patient outcome.
Ortuno and colleagues reviewed the current literature on post-arrest care and wrote an outstanding summary of how to optimally care for these patients. More specifically, they focused on post-arrest patients who demonstrate continued shock, or “post–cardiac arrest myocardial dysfunction” (PCAMD).
They propose three mechanisms for the pathogenesis of PCAMD: ischemia reperfusion phenomenon, systemic inflammatory response, and increased catecholamine release
I will skip through the details of the pathophysiology that they describe in the article, but I certainly do recommend that everyone review their descriptions.
Management of these patients begins with a good hemodynamic assessment, which includes clinical markers of perfusion (blood pressure, capillary refill), ECG, and point-of-care ultrasound (POCUS). If the initial assessment reveals an obvious cause of the cardiac arrest (e.g., massive pulmonary embolism, myocardial infarction, pericardial tamponade), then the underlying cause should be treated expeditiously.
In the absence of an obvious treatable cause of the shock, the fluid status and cardiac function should be addressed with POCUS. If the patient is hypovolemic, intravenous fluids should be administered. If the fluid status is adequate, POCUS should be used to estimate the patient’s ventricular function. If the ventricle appears to be hyperdynamic with good contractility, shock should be treated with norepinephrine. On the other hand, if the ventricle is hypodynamic, dobutamine should be substituted for norepinephrine or, more often, added to norepinephrine.
The above represents a simplified summary of the critical points, but the authors do delve into further detail and also discuss some other options for therapies, including steroids, coronary revascularization, extracorporeal membrane oxygenation, and so on. The review is very thoughtful, thorough, and definitely worth a full read.
Top myths of diagnosis and management of infectious diseases in hospital medicine
Most, if not all of us in medicine, have heard the saying that 50% of what we learn in medical school (or residency) will turn out to be wrong. I certainly believe in this concept and consequently, like many of you, I enjoy reading about myths and misconceptions that we have been taught. With that in mind, I have to say that I love this article because it seems to have been written specifically to address what I was taught!
This author group, consisting mostly of clinical PharmDs who are experts in antibiotic use, provide us with an evidence-based discussion of myths and pitfalls in how antibiotics are often used in current clinical practice. The authors review their top 10 myths involving the use of antibiotics in treating infections in the hospital setting. A few of these relate more to the inpatient setting, but here are my favorite emergency department (ED)–related myths that they address:
- “Antibiotics do no harm.” The authors address the risk-benefit of antibiotics based on assumed vs. confirmed infections, including a brief discussion of adverse drug effects.
- “Antibiotic durations of 7, 14, or 21 days are typically necessary.” The authors address appropriate duration of antibiotic use and the fact that unnecessarily long durations of use can lead to resistance. They also provide reassurance that some infections can be treated with quite short durations of antibiotics.
- “If one drug is good, two (or more!) is better.” The use of multiple antibiotics, often with overlapping bacterial coverage, is rampant in medicine and further increases the risk for adverse drug effects and resistance.
- “Oral antibiotics are not as good as intravenous antibiotics for hospitalized patients.” This is definitely a myth that I learned. I recall being taught by many senior physicians that anyone sick enough for admission should be treated with intravenous antibiotics. As it turns out, absorption and effectiveness of most oral antibiotics is just as good as intravenous antibiotics, and the oral formulations are often safer.
- “A history of a penicillin allergy means the patient can never receive a beta-lactam antibiotic.” This is a myth that was debunked quite a few years ago, but it seems that many clinicians still need a reminder.
The authors included five more myths that are worth the read. This is an article that needs to be disseminated among all hospital clinicians.
Guidelines for low-risk, recurrent abdominal pain in the emergency department
The Society for Academic Emergency Medicine (SAEM) recently initiated a program focused on creating evidence-based approaches to challenging chief complaints and presentations in the emergency department (ED). In 2021, they published an approach to managing patients with recurrent, low-risk chest pain in the ED. This past year, they published their second guideline, focused on the management of patients with low-risk, recurrent abdominal pain in the ED.
Recurrent low-risk abdominal pain is a common and vexing presentation to EDs around the world, and there is little prior published guidance. Do all of these patients need repeat imaging? How do we manage their pain? Are there nonabdominal conditions that should be considered?
Broder and colleagues did a fantastic review of the current literature and, on behalf of SAEM, have provided a rational approach to optimal management of these patients. The four major questions they addressed, with brief summaries of their recommendations, are:
- Should adult ED patients with low-risk, recurrent and previously undifferentiated abdominal pain receive a repeat CT abdomen-pelvis (CTAP) after a negative CTAP within the past 12 months? This is a typical question that we all ponder when managing these patients. Unfortunately, the writing group found insufficient evidence to definitively identify populations in whom CTAP was recommended vs could be safely withheld. It is a bit disappointing that there is no definite answer to the question. On the other hand, it is reassuring to know that the world’s best evidence essentially says that it is perfectly appropriate to use your own good clinical judgment.
- Should adult ED patients with low-risk, recurrent, and previously undifferentiated abdominal pain with a negative CTAP receive additional imaging with abdominal ultrasound? In this case, the writing group found enough evidence, though low-level, to suggest against routine ultrasound in the absence of concern specifically for pelvic or hepatobiliary pathology. Like most tests, ultrasound is best used when there are specific concerns rather than being used in an undifferentiated fashion.
- Should adult ED patients with low-risk, recurrent, and previously undifferentiated abdominal pain receive screening for depression/anxiety? The writing group found enough evidence, though low-level again, to suggest that screening for depression and/or anxiety be performed during the ED evaluation. This could lead to successful therapy for the abdominal pain.
- Should adult ED patients with low-risk, recurrent, and previously undifferentiated abdominal pain receive nonopioid and/or nonpharmacologic analgesics? The writing group found little evidence to suggest for or against these analgesics, but they made a consensus recommendation suggesting an opioid-minimizing strategy for pain control.
Although the final recommendations of the writing group were not definitive or based on the strongest level of evidence, I find it helpful to have this guidance, nevertheless, on behalf of a major national organization. I also find it helpful to know that even with the best evidence available, optimal patient care will often boil down to physician experience and gestalt. I should also add that the overall article is chock-full of pearls and helpful information that will further inform the readers’ decisions, and so the full version is definitely worth the read.
In summary
There you have it – my three favorite practice-changing articles of 2022. Although I have tried to provide key points here, the full discussions of those key points in the published articles will provide a great deal more education than I can offer in this brief write-up, and so I strongly encourage everyone to read the full versions. Please be sure to include in the comments section your own pick for favorite or must-read articles from the past year.
Amal Mattu, MD, is a professor, vice chair of education, and codirector of the emergency cardiology fellowship in the department of emergency medicine at the University of Maryland, Baltimore. She reported no relevant conflicts of interest.
A version of this article first appeared on Medscape.com.
When 2022 began, we started seeing some light at the end of the COVID-19 tunnel. Vaccines were widely available, and even with new variants of the virus still occasionally emerging, the rates of severe morbidity and mortality appeared to be decreasing.
Expectedly, journals appeared to start moving more toward mainstream topics and publications rather than what seemed like a major focus on COVID-19 publications. The resulting literature was fantastic.
Several of those topics were discussed in a prior Emergency Medicine Viewpoint from this news organization, and many more of the research advances of 2022 will be discussed in the near future. However, in this Viewpoint, I would like to present my annual review of my three “must-read” articles of the past year.
As in past years, I am choosing reviews of the literature rather than original research articles (which, all too often, become outdated or debunked within a few years). I choose these articles in the hopes that readers will not simply settle for my brief reviews of the key points but instead will feel compelled to download and read the entire articles. These publications address common conditions and quandaries we face in the daily practice of emergency medicine and are practice-changing.
Myocardial dysfunction after cardiac arrest: Tips and pitfalls
The management of post–cardiac arrest patients remains a hot topic in the resuscitation literature as we continue to understand that the immediate post-arrest period is critical to patient outcome.
Ortuno and colleagues reviewed the current literature on post-arrest care and wrote an outstanding summary of how to optimally care for these patients. More specifically, they focused on post-arrest patients who demonstrate continued shock, or “post–cardiac arrest myocardial dysfunction” (PCAMD).
They propose three mechanisms for the pathogenesis of PCAMD: ischemia reperfusion phenomenon, systemic inflammatory response, and increased catecholamine release
I will skip through the details of the pathophysiology that they describe in the article, but I certainly do recommend that everyone review their descriptions.
Management of these patients begins with a good hemodynamic assessment, which includes clinical markers of perfusion (blood pressure, capillary refill), ECG, and point-of-care ultrasound (POCUS). If the initial assessment reveals an obvious cause of the cardiac arrest (e.g., massive pulmonary embolism, myocardial infarction, pericardial tamponade), then the underlying cause should be treated expeditiously.
In the absence of an obvious treatable cause of the shock, the fluid status and cardiac function should be addressed with POCUS. If the patient is hypovolemic, intravenous fluids should be administered. If the fluid status is adequate, POCUS should be used to estimate the patient’s ventricular function. If the ventricle appears to be hyperdynamic with good contractility, shock should be treated with norepinephrine. On the other hand, if the ventricle is hypodynamic, dobutamine should be substituted for norepinephrine or, more often, added to norepinephrine.
The above represents a simplified summary of the critical points, but the authors do delve into further detail and also discuss some other options for therapies, including steroids, coronary revascularization, extracorporeal membrane oxygenation, and so on. The review is very thoughtful, thorough, and definitely worth a full read.
Top myths of diagnosis and management of infectious diseases in hospital medicine
Most, if not all of us in medicine, have heard the saying that 50% of what we learn in medical school (or residency) will turn out to be wrong. I certainly believe in this concept and consequently, like many of you, I enjoy reading about myths and misconceptions that we have been taught. With that in mind, I have to say that I love this article because it seems to have been written specifically to address what I was taught!
This author group, consisting mostly of clinical PharmDs who are experts in antibiotic use, provide us with an evidence-based discussion of myths and pitfalls in how antibiotics are often used in current clinical practice. The authors review their top 10 myths involving the use of antibiotics in treating infections in the hospital setting. A few of these relate more to the inpatient setting, but here are my favorite emergency department (ED)–related myths that they address:
- “Antibiotics do no harm.” The authors address the risk-benefit of antibiotics based on assumed vs. confirmed infections, including a brief discussion of adverse drug effects.
- “Antibiotic durations of 7, 14, or 21 days are typically necessary.” The authors address appropriate duration of antibiotic use and the fact that unnecessarily long durations of use can lead to resistance. They also provide reassurance that some infections can be treated with quite short durations of antibiotics.
- “If one drug is good, two (or more!) is better.” The use of multiple antibiotics, often with overlapping bacterial coverage, is rampant in medicine and further increases the risk for adverse drug effects and resistance.
- “Oral antibiotics are not as good as intravenous antibiotics for hospitalized patients.” This is definitely a myth that I learned. I recall being taught by many senior physicians that anyone sick enough for admission should be treated with intravenous antibiotics. As it turns out, absorption and effectiveness of most oral antibiotics is just as good as intravenous antibiotics, and the oral formulations are often safer.
- “A history of a penicillin allergy means the patient can never receive a beta-lactam antibiotic.” This is a myth that was debunked quite a few years ago, but it seems that many clinicians still need a reminder.
The authors included five more myths that are worth the read. This is an article that needs to be disseminated among all hospital clinicians.
Guidelines for low-risk, recurrent abdominal pain in the emergency department
The Society for Academic Emergency Medicine (SAEM) recently initiated a program focused on creating evidence-based approaches to challenging chief complaints and presentations in the emergency department (ED). In 2021, they published an approach to managing patients with recurrent, low-risk chest pain in the ED. This past year, they published their second guideline, focused on the management of patients with low-risk, recurrent abdominal pain in the ED.
Recurrent low-risk abdominal pain is a common and vexing presentation to EDs around the world, and there is little prior published guidance. Do all of these patients need repeat imaging? How do we manage their pain? Are there nonabdominal conditions that should be considered?
Broder and colleagues did a fantastic review of the current literature and, on behalf of SAEM, have provided a rational approach to optimal management of these patients. The four major questions they addressed, with brief summaries of their recommendations, are:
- Should adult ED patients with low-risk, recurrent and previously undifferentiated abdominal pain receive a repeat CT abdomen-pelvis (CTAP) after a negative CTAP within the past 12 months? This is a typical question that we all ponder when managing these patients. Unfortunately, the writing group found insufficient evidence to definitively identify populations in whom CTAP was recommended vs could be safely withheld. It is a bit disappointing that there is no definite answer to the question. On the other hand, it is reassuring to know that the world’s best evidence essentially says that it is perfectly appropriate to use your own good clinical judgment.
- Should adult ED patients with low-risk, recurrent, and previously undifferentiated abdominal pain with a negative CTAP receive additional imaging with abdominal ultrasound? In this case, the writing group found enough evidence, though low-level, to suggest against routine ultrasound in the absence of concern specifically for pelvic or hepatobiliary pathology. Like most tests, ultrasound is best used when there are specific concerns rather than being used in an undifferentiated fashion.
- Should adult ED patients with low-risk, recurrent, and previously undifferentiated abdominal pain receive screening for depression/anxiety? The writing group found enough evidence, though low-level again, to suggest that screening for depression and/or anxiety be performed during the ED evaluation. This could lead to successful therapy for the abdominal pain.
- Should adult ED patients with low-risk, recurrent, and previously undifferentiated abdominal pain receive nonopioid and/or nonpharmacologic analgesics? The writing group found little evidence to suggest for or against these analgesics, but they made a consensus recommendation suggesting an opioid-minimizing strategy for pain control.
Although the final recommendations of the writing group were not definitive or based on the strongest level of evidence, I find it helpful to have this guidance, nevertheless, on behalf of a major national organization. I also find it helpful to know that even with the best evidence available, optimal patient care will often boil down to physician experience and gestalt. I should also add that the overall article is chock-full of pearls and helpful information that will further inform the readers’ decisions, and so the full version is definitely worth the read.
In summary
There you have it – my three favorite practice-changing articles of 2022. Although I have tried to provide key points here, the full discussions of those key points in the published articles will provide a great deal more education than I can offer in this brief write-up, and so I strongly encourage everyone to read the full versions. Please be sure to include in the comments section your own pick for favorite or must-read articles from the past year.
Amal Mattu, MD, is a professor, vice chair of education, and codirector of the emergency cardiology fellowship in the department of emergency medicine at the University of Maryland, Baltimore. She reported no relevant conflicts of interest.
A version of this article first appeared on Medscape.com.
What is the optimal pad position in transcutaneous pacing?
Transvenous pacing is typically the most effective therapy for unstable bradycardia but it is invasive, takes some time to perform, and is a procedure for which many acute care physicians lack comfort and significant experience. Transcutaneous pacing (TCP), on the other hand, is fast, easy to perform, and tends to be well tolerated by most patients when they receive appropriate doses of analgesia.
Unfortunately, TCP often fails to produce electrical or, more importantly, mechanical capture. Oftentimes when capture initially fails, the electrical current is increased in hopes of gaining capture but much to the discomfort of the patient. Increased body mass index can contribute to failure to capture, but what about TCP pad position? Despite recommendations for TCP in the United States and European resuscitation guidelines for many years, until now, no studies have evaluated optimal pad position for TCP. As a result, the default position for most clinicians using TCP has been the anterior-lateral (AL) position on the chest wall.
A study published in October 2022 compared the common AL position (anterior pad placed at the right upper chest and lateral pad placed over the left lower rib cage at the mid-axillary line) with the anterior-posterior (AP) position (anterior pad placed on the left chest over the apex of the heart and the posterior pad on the left mid-back area approximating the level of the mid-portion of the heart). The AP position has become more commonly used in defibrillating arrested hearts because it more accurately sends the current through the left ventricle. The concern with the AL position, especially in patients with large body habitus, is that the vector of the current may partially or entirely miss the left ventricle.
Moayedi and colleagues hypothesized that optimal TCP should employ pad placement that is similar to that used during optimal defibrillation attempts. They conducted a study comparing AL versus AP position during TCP and published their results in two parts, which will be discussed together.
The investigators evaluated 20 patients (6 women, 14 men) who had elective cardioversion of atrial fibrillation in the electrophysiology lab (Resuscitation. 2022 Dec;181:140-6). After successful cardioversion to sinus rhythm, the cardioversion pads were removed, and two new sets of pacer pads were placed on the patients’ chests. Pads were placed in both the AL and the AP positions, as previously described. Starting at a current output of 40 mA, the output was slowly increased on one set of pads until mechanical capture was obtained at the same rate as the pacer setting for at least 10 seconds. Pacing was then discontinued, but then the process was repeated using the second set of pads. The order in which the positions were tested (that is, AL tested first vs. AP tested first) was alternated. If capture was not obtained by 140 mA (the pacer’s maximum output), failure to capture was documented. Both positions were tested in all patients except for three cases where the second position was not tested because of inadequate analgesia.
The investigators found that 8 in 19 (42%) of the AL trials and 14 in 18 (78%) of the AP trials successfully captured. For the 17 participants who completed both trials, both positions captured in 8 in 17 (47%). AP but not AL was captured in 5 in 17 (29%); AL but not AP was captured in 0 cases. Neither position captured in 4 in 17 (24%). Of note, there was no association between successful capture and body mass index, chest circumference, or chest diameter. The AP position was more successful in both women and men, compared with the AL position. The investigators also found that, among the successful trials, the AP position tended to capture at lower currents than the AL position (93 mA vs. 126 mA).
In summary
TCP is a potentially lifesaving intervention in the treatment of patients with unstable bradycardia. Many of us who have attempted to perform TCP on unstable patients have frequently been disappointed with the results. In retrospect, however, I can recall that each time I have attempted this procedure, it has been using pads placed in the AL position.
Now for the first time we have data indicating that the standard AL position may be suboptimal, compared with the AP position. The study by Moayedi and colleagues is small, but the results are compelling, and the AP pad placement intuitively makes more sense. By using the AP pad placement, which provides greater likelihood of electrical current passing through the left ventricle, we should expect a greater likelihood of successful capture during attempts at TCP. In addition, we may anticipate lower analgesia needs if the AP position requires less current for success. Kudos to Moayedi and colleagues for performing a novel study of a critical procedure in acute care medicine.
Amal Mattu, MD, is a professor, vice chair of education, and codirector of the emergency cardiology fellowship in the department of emergency medicine at the University of Maryland, Baltimore. He had no disclosures. A version of this article first appeared on Medscape.com.
Transvenous pacing is typically the most effective therapy for unstable bradycardia but it is invasive, takes some time to perform, and is a procedure for which many acute care physicians lack comfort and significant experience. Transcutaneous pacing (TCP), on the other hand, is fast, easy to perform, and tends to be well tolerated by most patients when they receive appropriate doses of analgesia.
Unfortunately, TCP often fails to produce electrical or, more importantly, mechanical capture. Oftentimes when capture initially fails, the electrical current is increased in hopes of gaining capture but much to the discomfort of the patient. Increased body mass index can contribute to failure to capture, but what about TCP pad position? Despite recommendations for TCP in the United States and European resuscitation guidelines for many years, until now, no studies have evaluated optimal pad position for TCP. As a result, the default position for most clinicians using TCP has been the anterior-lateral (AL) position on the chest wall.
A study published in October 2022 compared the common AL position (anterior pad placed at the right upper chest and lateral pad placed over the left lower rib cage at the mid-axillary line) with the anterior-posterior (AP) position (anterior pad placed on the left chest over the apex of the heart and the posterior pad on the left mid-back area approximating the level of the mid-portion of the heart). The AP position has become more commonly used in defibrillating arrested hearts because it more accurately sends the current through the left ventricle. The concern with the AL position, especially in patients with large body habitus, is that the vector of the current may partially or entirely miss the left ventricle.
Moayedi and colleagues hypothesized that optimal TCP should employ pad placement that is similar to that used during optimal defibrillation attempts. They conducted a study comparing AL versus AP position during TCP and published their results in two parts, which will be discussed together.
The investigators evaluated 20 patients (6 women, 14 men) who had elective cardioversion of atrial fibrillation in the electrophysiology lab (Resuscitation. 2022 Dec;181:140-6). After successful cardioversion to sinus rhythm, the cardioversion pads were removed, and two new sets of pacer pads were placed on the patients’ chests. Pads were placed in both the AL and the AP positions, as previously described. Starting at a current output of 40 mA, the output was slowly increased on one set of pads until mechanical capture was obtained at the same rate as the pacer setting for at least 10 seconds. Pacing was then discontinued, but then the process was repeated using the second set of pads. The order in which the positions were tested (that is, AL tested first vs. AP tested first) was alternated. If capture was not obtained by 140 mA (the pacer’s maximum output), failure to capture was documented. Both positions were tested in all patients except for three cases where the second position was not tested because of inadequate analgesia.
The investigators found that 8 in 19 (42%) of the AL trials and 14 in 18 (78%) of the AP trials successfully captured. For the 17 participants who completed both trials, both positions captured in 8 in 17 (47%). AP but not AL was captured in 5 in 17 (29%); AL but not AP was captured in 0 cases. Neither position captured in 4 in 17 (24%). Of note, there was no association between successful capture and body mass index, chest circumference, or chest diameter. The AP position was more successful in both women and men, compared with the AL position. The investigators also found that, among the successful trials, the AP position tended to capture at lower currents than the AL position (93 mA vs. 126 mA).
In summary
TCP is a potentially lifesaving intervention in the treatment of patients with unstable bradycardia. Many of us who have attempted to perform TCP on unstable patients have frequently been disappointed with the results. In retrospect, however, I can recall that each time I have attempted this procedure, it has been using pads placed in the AL position.
Now for the first time we have data indicating that the standard AL position may be suboptimal, compared with the AP position. The study by Moayedi and colleagues is small, but the results are compelling, and the AP pad placement intuitively makes more sense. By using the AP pad placement, which provides greater likelihood of electrical current passing through the left ventricle, we should expect a greater likelihood of successful capture during attempts at TCP. In addition, we may anticipate lower analgesia needs if the AP position requires less current for success. Kudos to Moayedi and colleagues for performing a novel study of a critical procedure in acute care medicine.
Amal Mattu, MD, is a professor, vice chair of education, and codirector of the emergency cardiology fellowship in the department of emergency medicine at the University of Maryland, Baltimore. He had no disclosures. A version of this article first appeared on Medscape.com.
Transvenous pacing is typically the most effective therapy for unstable bradycardia but it is invasive, takes some time to perform, and is a procedure for which many acute care physicians lack comfort and significant experience. Transcutaneous pacing (TCP), on the other hand, is fast, easy to perform, and tends to be well tolerated by most patients when they receive appropriate doses of analgesia.
Unfortunately, TCP often fails to produce electrical or, more importantly, mechanical capture. Oftentimes when capture initially fails, the electrical current is increased in hopes of gaining capture but much to the discomfort of the patient. Increased body mass index can contribute to failure to capture, but what about TCP pad position? Despite recommendations for TCP in the United States and European resuscitation guidelines for many years, until now, no studies have evaluated optimal pad position for TCP. As a result, the default position for most clinicians using TCP has been the anterior-lateral (AL) position on the chest wall.
A study published in October 2022 compared the common AL position (anterior pad placed at the right upper chest and lateral pad placed over the left lower rib cage at the mid-axillary line) with the anterior-posterior (AP) position (anterior pad placed on the left chest over the apex of the heart and the posterior pad on the left mid-back area approximating the level of the mid-portion of the heart). The AP position has become more commonly used in defibrillating arrested hearts because it more accurately sends the current through the left ventricle. The concern with the AL position, especially in patients with large body habitus, is that the vector of the current may partially or entirely miss the left ventricle.
Moayedi and colleagues hypothesized that optimal TCP should employ pad placement that is similar to that used during optimal defibrillation attempts. They conducted a study comparing AL versus AP position during TCP and published their results in two parts, which will be discussed together.
The investigators evaluated 20 patients (6 women, 14 men) who had elective cardioversion of atrial fibrillation in the electrophysiology lab (Resuscitation. 2022 Dec;181:140-6). After successful cardioversion to sinus rhythm, the cardioversion pads were removed, and two new sets of pacer pads were placed on the patients’ chests. Pads were placed in both the AL and the AP positions, as previously described. Starting at a current output of 40 mA, the output was slowly increased on one set of pads until mechanical capture was obtained at the same rate as the pacer setting for at least 10 seconds. Pacing was then discontinued, but then the process was repeated using the second set of pads. The order in which the positions were tested (that is, AL tested first vs. AP tested first) was alternated. If capture was not obtained by 140 mA (the pacer’s maximum output), failure to capture was documented. Both positions were tested in all patients except for three cases where the second position was not tested because of inadequate analgesia.
The investigators found that 8 in 19 (42%) of the AL trials and 14 in 18 (78%) of the AP trials successfully captured. For the 17 participants who completed both trials, both positions captured in 8 in 17 (47%). AP but not AL was captured in 5 in 17 (29%); AL but not AP was captured in 0 cases. Neither position captured in 4 in 17 (24%). Of note, there was no association between successful capture and body mass index, chest circumference, or chest diameter. The AP position was more successful in both women and men, compared with the AL position. The investigators also found that, among the successful trials, the AP position tended to capture at lower currents than the AL position (93 mA vs. 126 mA).
In summary
TCP is a potentially lifesaving intervention in the treatment of patients with unstable bradycardia. Many of us who have attempted to perform TCP on unstable patients have frequently been disappointed with the results. In retrospect, however, I can recall that each time I have attempted this procedure, it has been using pads placed in the AL position.
Now for the first time we have data indicating that the standard AL position may be suboptimal, compared with the AP position. The study by Moayedi and colleagues is small, but the results are compelling, and the AP pad placement intuitively makes more sense. By using the AP pad placement, which provides greater likelihood of electrical current passing through the left ventricle, we should expect a greater likelihood of successful capture during attempts at TCP. In addition, we may anticipate lower analgesia needs if the AP position requires less current for success. Kudos to Moayedi and colleagues for performing a novel study of a critical procedure in acute care medicine.
Amal Mattu, MD, is a professor, vice chair of education, and codirector of the emergency cardiology fellowship in the department of emergency medicine at the University of Maryland, Baltimore. He had no disclosures. A version of this article first appeared on Medscape.com.
The must-read acute care medicine articles from 2021
When 2021 began, there appeared to be light at the end of the long and dark COVID-19 pandemic. A vaccine was introduced, the “curve” had been flattened, and by spring, businesses were slowly starting to open. Whereas the medical literature of 2020 seemed to be almost entirely focused on COVID-19, medical writers, researchers, and educators seemed to slowly start turning more attention back to non–COVID-related topics in 2021.
Unfortunately, as I write this, the Omicron variant of the coronavirus is in full swing, and much of our attention has once again turned back to COVID-19. However, we are able to look back on 2021 and acknowledge a wealth of fantastic original research articles and guidelines which have improved patient care in many ways.
Specifically, I have chosen articles that did not appear to gain widespread notoriety in emergency medicine but are, nevertheless, worthy of your time and attention. Note that this write-up serves as a summary only, and I encourage interested readers to peruse the full manuscripts for further details. I am limiting my recap to two articles.
Recommendations on difficult airway management
Emergency physicians are well trained in airway management, and a major part of that training includes the preintubation anatomic assessment of the airway. However, there are few recommendations on the physiological considerations for airway management.
A set of recommendations from the Society for Airway Management was written primarily with anesthesiologists in mind, but many of the recommendations listed below are very relevant to emergency physicians as well. The authors make recommendations for patients who are hypoxic or hypotensive prior to induction, for patients with right ventricular dysfunction, for patients with severe metabolic acidosis, and for neurologically injured patients. Some of the key pearls follow.
Patients with hypoxemia
- The importance of preoxygenation before intubation is once again emphasized, and this can be performed using high-flow oxygen for at least 3 minutes, or (in a cooperative patient) with eight vital capacity breaths.
- Maintenance of oxygenation during the apneic period should be continued. Apneic oxygenation can be provided with a nasal cannula at 15 liters per minute or with a high-flow nasal oxygen system at 40-70 LPM.
- For patients with significant shunt physiology or reduced functional residual capacity (for example, late pregnancy, obesity, or acute respiratory distress syndrome), preoxygenation should be performed with positive end expiratory pressure (PEEP) using noninvasive positive pressure ventilation or bag-valve mask ventilation with a PEEP valve. When higher levels of PEEP are required, an extraglottic device should be considered during preoxygenation.
- For patients with refractory hypoxemia, awake intubation to maintain spontaneous respirations should be considered.
- Patients should be preoxygenated in the upright position when possible.
- Ramped-up position (head elevated so as to bring the external auditory canal in the same horizontal line as the sternal notch) should be performed when possible in order to improve the grade of view, improve oxygenation, and reduce aspiration.
Patients with hypotension
- Patients should be screened for high risk for hemodynamic collapse prior to administration of induction medications and intubation by assessing the stroke index. A stroke index greater than 0.7 predicts a high risk. These patients should receive hemodynamic optimization (for example, intravenous fluids, administration of vasopressors) whenever possible, prior to administration of induction medications and intubation.
- Vasopressor infusions are preferable to bolus-dosed vasopressors. However, if vasopressor infusions are not possible, bolus-dosed vasopressors should be available and used to maintain systemic pressure during and after the intubation until an infusion can be started. When bolus-dosed vasopressors are used, diluted epinephrine should be considered as the vasopressor of choice in patients with depressed myocardial function.
Patients with right ventricular (RV) dysfunction
- Patients should be screened for significant RV dysfunction prior to intubation because of their high risk for hemodynamic decompensation with positive pressure ventilation.
- RV dysfunction may sometimes worsen with fluid administration. Fluid-intolerant patients may instead need RV afterload reduction with inhaled or intravenous pulmonary vasodilators.
- Patients with RV failure–induced shock should be considered for preintubation extracorporeal membrane oxygenation if available.
- Patients with RV volume overload should receive diuresis prior to intubation.
- Ventilator settings should aim to avoid hypercapnia, maintain low airway pressures, and use a higher PEEP to avoid atelectasis.
Patients with severe metabolic acidosis
- Patients with severe metabolic acidosis are at high risk for decompensation after intubation because of volume depletion and inadequate alveolar ventilation, resulting in profound acidosis.
- Patients with high minute ventilation prior to intubation should be considered for awake intubation to maintain spontaneous respirations. Otherwise, consider a spontaneous breathing mode after intubation with a high minute ventilation (that is, use a higher-than-normal respiratory rate on the ventilator in order to reproduce the preintubation minute ventilation). Apnea time should be minimized in order to minimize worsening acidosis.
- Preintubation bicarbonate boluses to prevent worsening acidosis are controversial and lack data showing any benefit.
Neurologically injured patients
- Eucapnia and normoxia should be maintained before, during, and after intubation to maintain stable cerebral blood flow.
- Hemodynamically neutral induction agents should be used.
- Patients should be positioned with the head of bed elevated to 30° upright when possible.
- Limit PEEP post intubation in order to promote venous drainage.
Evidence update for the treatment of anaphylaxis
The treatment of anaphylaxis is considered bread and butter in emergency and acute care medicine, but a great deal of what we have learned over the years is not well supported by the literature. In an article published in Resuscitation, the Anaphylaxis Working Group of the Resuscitation Council of the United Kingdom performed an evidence review regarding the emergency treatment of anaphylaxis.
A summary of key points includes:
- Anaphylaxis is defined as a systemic hypersensitivity reaction, usually rapid in onset, with potentially life-threatening compromise in airway, breathing, and/or circulation.
- The most important treatment is epinephrine (EPI), with an initial recommended dose in adults of 0.5 mg administered via the intramuscular (IM) route. Up to 10% of patients have a suboptimal response to one dose, but 98% will respond by the third dose; therefore, these authors recommend repeating the IM EPI every 5 minutes, if needed, up to three doses. There is no evidence to support any alternative or additional vasopressors, and so they should only be used if EPI is ineffective. Intravenous EPI is not recommended initially except in the perioperative setting where close monitoring can be performed. If intravenous EPI is used, the authors recommend an intravenous infusion rather than bolus dosing.
- Intravenous fluid bolus dosing is recommended in the majority of cases of anaphylaxis, regardless of presence or absence of hemodynamic compromise, because of the profound reduction in venous tone and third-spacing that typically occurs.
- Antihistamines are not recommended in early treatment. They are only effective for reversing skin manifestations of anaphylaxis (which EPI treats as well), and the sedation they produce can confound the proper ongoing evaluation of the patient. Furthermore, the use of antihistamines early in the treatment of anaphylaxis has been found to produce delays in proper use of EPI.
- Steroids are not recommended in early treatment. They help only with the late phase of inflammatory response, but despite that, there is no good evidence that they decrease the biphasic response of anaphylaxis. There is some emerging evidence that the use of steroids may actually be associated with increased morbidity even after correcting for anaphylaxis severity. The authors recommended the use of steroids in anaphylaxis only for patients with poorly controlled asthma and possibly for patients with refractory anaphylaxis. Inhaled beta-agonists are recommended in anaphylaxis only for patients with lower respiratory tract symptoms caused by anaphylaxis, but warned that the inhaled beta-agonists should not delay proper use of EPI.
- The optimal observation period before discharge for stable patients is unknown. The authors noted the recommendations of the Joint Task Force on Practice Parameters of the American Academy of Allergy, Asthma, & Immunology and the American College of Allergy, Asthma, and Immunology: Biphasic reactions were more common in patients with severe initial symptoms – for example, those requiring more than one dose of EPI; therefore, these patients are recommended to have “extended observation.” Lower-risk patients with resolved symptoms of anaphylaxis can be observed for 1 hour, which would capture 95% of biphasic reactions in this group of patients.
Summary and other honorable mentions
There you have it. My two favorite practice-changing (non–COVID-19) articles of 2021. Not surprisingly, both articles deal largely with airway and hemodynamic concerns – the ABC’s of emergency medicine. Although these bulleted pearls provide key points from these two articles, the full discussions of those key points in the articles would provide a great deal more education than I can provide in this brief write-up, and so I strongly encourage everyone to read the full articles.
I also encourage readers to peruse the following “honorable mention” articles: Stiell and colleagues published a “Best Practices Checklist” on behalf of the Canadian Association of Emergency Physicians pertaining to the management of acute atrial fibrillation and atrial flutter; and on behalf of the American Heart Association (in collaboration with several other major organizations), Gulati and colleagues published the 2021 Guideline for the Evaluation and Diagnosis of Chest Pain. Both publications show us how we should strive to manage atrial fibrillation and chest pain, respectively, in the emergency department for years to come.
Amal Mattu, MD, is a professor, vice chair of education, and codirector of the emergency cardiology fellowship in the department of emergency medicine at the University of Maryland, Baltimore.
A version of this article first appeared on Medscape.com.
When 2021 began, there appeared to be light at the end of the long and dark COVID-19 pandemic. A vaccine was introduced, the “curve” had been flattened, and by spring, businesses were slowly starting to open. Whereas the medical literature of 2020 seemed to be almost entirely focused on COVID-19, medical writers, researchers, and educators seemed to slowly start turning more attention back to non–COVID-related topics in 2021.
Unfortunately, as I write this, the Omicron variant of the coronavirus is in full swing, and much of our attention has once again turned back to COVID-19. However, we are able to look back on 2021 and acknowledge a wealth of fantastic original research articles and guidelines which have improved patient care in many ways.
Specifically, I have chosen articles that did not appear to gain widespread notoriety in emergency medicine but are, nevertheless, worthy of your time and attention. Note that this write-up serves as a summary only, and I encourage interested readers to peruse the full manuscripts for further details. I am limiting my recap to two articles.
Recommendations on difficult airway management
Emergency physicians are well trained in airway management, and a major part of that training includes the preintubation anatomic assessment of the airway. However, there are few recommendations on the physiological considerations for airway management.
A set of recommendations from the Society for Airway Management was written primarily with anesthesiologists in mind, but many of the recommendations listed below are very relevant to emergency physicians as well. The authors make recommendations for patients who are hypoxic or hypotensive prior to induction, for patients with right ventricular dysfunction, for patients with severe metabolic acidosis, and for neurologically injured patients. Some of the key pearls follow.
Patients with hypoxemia
- The importance of preoxygenation before intubation is once again emphasized, and this can be performed using high-flow oxygen for at least 3 minutes, or (in a cooperative patient) with eight vital capacity breaths.
- Maintenance of oxygenation during the apneic period should be continued. Apneic oxygenation can be provided with a nasal cannula at 15 liters per minute or with a high-flow nasal oxygen system at 40-70 LPM.
- For patients with significant shunt physiology or reduced functional residual capacity (for example, late pregnancy, obesity, or acute respiratory distress syndrome), preoxygenation should be performed with positive end expiratory pressure (PEEP) using noninvasive positive pressure ventilation or bag-valve mask ventilation with a PEEP valve. When higher levels of PEEP are required, an extraglottic device should be considered during preoxygenation.
- For patients with refractory hypoxemia, awake intubation to maintain spontaneous respirations should be considered.
- Patients should be preoxygenated in the upright position when possible.
- Ramped-up position (head elevated so as to bring the external auditory canal in the same horizontal line as the sternal notch) should be performed when possible in order to improve the grade of view, improve oxygenation, and reduce aspiration.
Patients with hypotension
- Patients should be screened for high risk for hemodynamic collapse prior to administration of induction medications and intubation by assessing the stroke index. A stroke index greater than 0.7 predicts a high risk. These patients should receive hemodynamic optimization (for example, intravenous fluids, administration of vasopressors) whenever possible, prior to administration of induction medications and intubation.
- Vasopressor infusions are preferable to bolus-dosed vasopressors. However, if vasopressor infusions are not possible, bolus-dosed vasopressors should be available and used to maintain systemic pressure during and after the intubation until an infusion can be started. When bolus-dosed vasopressors are used, diluted epinephrine should be considered as the vasopressor of choice in patients with depressed myocardial function.
Patients with right ventricular (RV) dysfunction
- Patients should be screened for significant RV dysfunction prior to intubation because of their high risk for hemodynamic decompensation with positive pressure ventilation.
- RV dysfunction may sometimes worsen with fluid administration. Fluid-intolerant patients may instead need RV afterload reduction with inhaled or intravenous pulmonary vasodilators.
- Patients with RV failure–induced shock should be considered for preintubation extracorporeal membrane oxygenation if available.
- Patients with RV volume overload should receive diuresis prior to intubation.
- Ventilator settings should aim to avoid hypercapnia, maintain low airway pressures, and use a higher PEEP to avoid atelectasis.
Patients with severe metabolic acidosis
- Patients with severe metabolic acidosis are at high risk for decompensation after intubation because of volume depletion and inadequate alveolar ventilation, resulting in profound acidosis.
- Patients with high minute ventilation prior to intubation should be considered for awake intubation to maintain spontaneous respirations. Otherwise, consider a spontaneous breathing mode after intubation with a high minute ventilation (that is, use a higher-than-normal respiratory rate on the ventilator in order to reproduce the preintubation minute ventilation). Apnea time should be minimized in order to minimize worsening acidosis.
- Preintubation bicarbonate boluses to prevent worsening acidosis are controversial and lack data showing any benefit.
Neurologically injured patients
- Eucapnia and normoxia should be maintained before, during, and after intubation to maintain stable cerebral blood flow.
- Hemodynamically neutral induction agents should be used.
- Patients should be positioned with the head of bed elevated to 30° upright when possible.
- Limit PEEP post intubation in order to promote venous drainage.
Evidence update for the treatment of anaphylaxis
The treatment of anaphylaxis is considered bread and butter in emergency and acute care medicine, but a great deal of what we have learned over the years is not well supported by the literature. In an article published in Resuscitation, the Anaphylaxis Working Group of the Resuscitation Council of the United Kingdom performed an evidence review regarding the emergency treatment of anaphylaxis.
A summary of key points includes:
- Anaphylaxis is defined as a systemic hypersensitivity reaction, usually rapid in onset, with potentially life-threatening compromise in airway, breathing, and/or circulation.
- The most important treatment is epinephrine (EPI), with an initial recommended dose in adults of 0.5 mg administered via the intramuscular (IM) route. Up to 10% of patients have a suboptimal response to one dose, but 98% will respond by the third dose; therefore, these authors recommend repeating the IM EPI every 5 minutes, if needed, up to three doses. There is no evidence to support any alternative or additional vasopressors, and so they should only be used if EPI is ineffective. Intravenous EPI is not recommended initially except in the perioperative setting where close monitoring can be performed. If intravenous EPI is used, the authors recommend an intravenous infusion rather than bolus dosing.
- Intravenous fluid bolus dosing is recommended in the majority of cases of anaphylaxis, regardless of presence or absence of hemodynamic compromise, because of the profound reduction in venous tone and third-spacing that typically occurs.
- Antihistamines are not recommended in early treatment. They are only effective for reversing skin manifestations of anaphylaxis (which EPI treats as well), and the sedation they produce can confound the proper ongoing evaluation of the patient. Furthermore, the use of antihistamines early in the treatment of anaphylaxis has been found to produce delays in proper use of EPI.
- Steroids are not recommended in early treatment. They help only with the late phase of inflammatory response, but despite that, there is no good evidence that they decrease the biphasic response of anaphylaxis. There is some emerging evidence that the use of steroids may actually be associated with increased morbidity even after correcting for anaphylaxis severity. The authors recommended the use of steroids in anaphylaxis only for patients with poorly controlled asthma and possibly for patients with refractory anaphylaxis. Inhaled beta-agonists are recommended in anaphylaxis only for patients with lower respiratory tract symptoms caused by anaphylaxis, but warned that the inhaled beta-agonists should not delay proper use of EPI.
- The optimal observation period before discharge for stable patients is unknown. The authors noted the recommendations of the Joint Task Force on Practice Parameters of the American Academy of Allergy, Asthma, & Immunology and the American College of Allergy, Asthma, and Immunology: Biphasic reactions were more common in patients with severe initial symptoms – for example, those requiring more than one dose of EPI; therefore, these patients are recommended to have “extended observation.” Lower-risk patients with resolved symptoms of anaphylaxis can be observed for 1 hour, which would capture 95% of biphasic reactions in this group of patients.
Summary and other honorable mentions
There you have it. My two favorite practice-changing (non–COVID-19) articles of 2021. Not surprisingly, both articles deal largely with airway and hemodynamic concerns – the ABC’s of emergency medicine. Although these bulleted pearls provide key points from these two articles, the full discussions of those key points in the articles would provide a great deal more education than I can provide in this brief write-up, and so I strongly encourage everyone to read the full articles.
I also encourage readers to peruse the following “honorable mention” articles: Stiell and colleagues published a “Best Practices Checklist” on behalf of the Canadian Association of Emergency Physicians pertaining to the management of acute atrial fibrillation and atrial flutter; and on behalf of the American Heart Association (in collaboration with several other major organizations), Gulati and colleagues published the 2021 Guideline for the Evaluation and Diagnosis of Chest Pain. Both publications show us how we should strive to manage atrial fibrillation and chest pain, respectively, in the emergency department for years to come.
Amal Mattu, MD, is a professor, vice chair of education, and codirector of the emergency cardiology fellowship in the department of emergency medicine at the University of Maryland, Baltimore.
A version of this article first appeared on Medscape.com.
When 2021 began, there appeared to be light at the end of the long and dark COVID-19 pandemic. A vaccine was introduced, the “curve” had been flattened, and by spring, businesses were slowly starting to open. Whereas the medical literature of 2020 seemed to be almost entirely focused on COVID-19, medical writers, researchers, and educators seemed to slowly start turning more attention back to non–COVID-related topics in 2021.
Unfortunately, as I write this, the Omicron variant of the coronavirus is in full swing, and much of our attention has once again turned back to COVID-19. However, we are able to look back on 2021 and acknowledge a wealth of fantastic original research articles and guidelines which have improved patient care in many ways.
Specifically, I have chosen articles that did not appear to gain widespread notoriety in emergency medicine but are, nevertheless, worthy of your time and attention. Note that this write-up serves as a summary only, and I encourage interested readers to peruse the full manuscripts for further details. I am limiting my recap to two articles.
Recommendations on difficult airway management
Emergency physicians are well trained in airway management, and a major part of that training includes the preintubation anatomic assessment of the airway. However, there are few recommendations on the physiological considerations for airway management.
A set of recommendations from the Society for Airway Management was written primarily with anesthesiologists in mind, but many of the recommendations listed below are very relevant to emergency physicians as well. The authors make recommendations for patients who are hypoxic or hypotensive prior to induction, for patients with right ventricular dysfunction, for patients with severe metabolic acidosis, and for neurologically injured patients. Some of the key pearls follow.
Patients with hypoxemia
- The importance of preoxygenation before intubation is once again emphasized, and this can be performed using high-flow oxygen for at least 3 minutes, or (in a cooperative patient) with eight vital capacity breaths.
- Maintenance of oxygenation during the apneic period should be continued. Apneic oxygenation can be provided with a nasal cannula at 15 liters per minute or with a high-flow nasal oxygen system at 40-70 LPM.
- For patients with significant shunt physiology or reduced functional residual capacity (for example, late pregnancy, obesity, or acute respiratory distress syndrome), preoxygenation should be performed with positive end expiratory pressure (PEEP) using noninvasive positive pressure ventilation or bag-valve mask ventilation with a PEEP valve. When higher levels of PEEP are required, an extraglottic device should be considered during preoxygenation.
- For patients with refractory hypoxemia, awake intubation to maintain spontaneous respirations should be considered.
- Patients should be preoxygenated in the upright position when possible.
- Ramped-up position (head elevated so as to bring the external auditory canal in the same horizontal line as the sternal notch) should be performed when possible in order to improve the grade of view, improve oxygenation, and reduce aspiration.
Patients with hypotension
- Patients should be screened for high risk for hemodynamic collapse prior to administration of induction medications and intubation by assessing the stroke index. A stroke index greater than 0.7 predicts a high risk. These patients should receive hemodynamic optimization (for example, intravenous fluids, administration of vasopressors) whenever possible, prior to administration of induction medications and intubation.
- Vasopressor infusions are preferable to bolus-dosed vasopressors. However, if vasopressor infusions are not possible, bolus-dosed vasopressors should be available and used to maintain systemic pressure during and after the intubation until an infusion can be started. When bolus-dosed vasopressors are used, diluted epinephrine should be considered as the vasopressor of choice in patients with depressed myocardial function.
Patients with right ventricular (RV) dysfunction
- Patients should be screened for significant RV dysfunction prior to intubation because of their high risk for hemodynamic decompensation with positive pressure ventilation.
- RV dysfunction may sometimes worsen with fluid administration. Fluid-intolerant patients may instead need RV afterload reduction with inhaled or intravenous pulmonary vasodilators.
- Patients with RV failure–induced shock should be considered for preintubation extracorporeal membrane oxygenation if available.
- Patients with RV volume overload should receive diuresis prior to intubation.
- Ventilator settings should aim to avoid hypercapnia, maintain low airway pressures, and use a higher PEEP to avoid atelectasis.
Patients with severe metabolic acidosis
- Patients with severe metabolic acidosis are at high risk for decompensation after intubation because of volume depletion and inadequate alveolar ventilation, resulting in profound acidosis.
- Patients with high minute ventilation prior to intubation should be considered for awake intubation to maintain spontaneous respirations. Otherwise, consider a spontaneous breathing mode after intubation with a high minute ventilation (that is, use a higher-than-normal respiratory rate on the ventilator in order to reproduce the preintubation minute ventilation). Apnea time should be minimized in order to minimize worsening acidosis.
- Preintubation bicarbonate boluses to prevent worsening acidosis are controversial and lack data showing any benefit.
Neurologically injured patients
- Eucapnia and normoxia should be maintained before, during, and after intubation to maintain stable cerebral blood flow.
- Hemodynamically neutral induction agents should be used.
- Patients should be positioned with the head of bed elevated to 30° upright when possible.
- Limit PEEP post intubation in order to promote venous drainage.
Evidence update for the treatment of anaphylaxis
The treatment of anaphylaxis is considered bread and butter in emergency and acute care medicine, but a great deal of what we have learned over the years is not well supported by the literature. In an article published in Resuscitation, the Anaphylaxis Working Group of the Resuscitation Council of the United Kingdom performed an evidence review regarding the emergency treatment of anaphylaxis.
A summary of key points includes:
- Anaphylaxis is defined as a systemic hypersensitivity reaction, usually rapid in onset, with potentially life-threatening compromise in airway, breathing, and/or circulation.
- The most important treatment is epinephrine (EPI), with an initial recommended dose in adults of 0.5 mg administered via the intramuscular (IM) route. Up to 10% of patients have a suboptimal response to one dose, but 98% will respond by the third dose; therefore, these authors recommend repeating the IM EPI every 5 minutes, if needed, up to three doses. There is no evidence to support any alternative or additional vasopressors, and so they should only be used if EPI is ineffective. Intravenous EPI is not recommended initially except in the perioperative setting where close monitoring can be performed. If intravenous EPI is used, the authors recommend an intravenous infusion rather than bolus dosing.
- Intravenous fluid bolus dosing is recommended in the majority of cases of anaphylaxis, regardless of presence or absence of hemodynamic compromise, because of the profound reduction in venous tone and third-spacing that typically occurs.
- Antihistamines are not recommended in early treatment. They are only effective for reversing skin manifestations of anaphylaxis (which EPI treats as well), and the sedation they produce can confound the proper ongoing evaluation of the patient. Furthermore, the use of antihistamines early in the treatment of anaphylaxis has been found to produce delays in proper use of EPI.
- Steroids are not recommended in early treatment. They help only with the late phase of inflammatory response, but despite that, there is no good evidence that they decrease the biphasic response of anaphylaxis. There is some emerging evidence that the use of steroids may actually be associated with increased morbidity even after correcting for anaphylaxis severity. The authors recommended the use of steroids in anaphylaxis only for patients with poorly controlled asthma and possibly for patients with refractory anaphylaxis. Inhaled beta-agonists are recommended in anaphylaxis only for patients with lower respiratory tract symptoms caused by anaphylaxis, but warned that the inhaled beta-agonists should not delay proper use of EPI.
- The optimal observation period before discharge for stable patients is unknown. The authors noted the recommendations of the Joint Task Force on Practice Parameters of the American Academy of Allergy, Asthma, & Immunology and the American College of Allergy, Asthma, and Immunology: Biphasic reactions were more common in patients with severe initial symptoms – for example, those requiring more than one dose of EPI; therefore, these patients are recommended to have “extended observation.” Lower-risk patients with resolved symptoms of anaphylaxis can be observed for 1 hour, which would capture 95% of biphasic reactions in this group of patients.
Summary and other honorable mentions
There you have it. My two favorite practice-changing (non–COVID-19) articles of 2021. Not surprisingly, both articles deal largely with airway and hemodynamic concerns – the ABC’s of emergency medicine. Although these bulleted pearls provide key points from these two articles, the full discussions of those key points in the articles would provide a great deal more education than I can provide in this brief write-up, and so I strongly encourage everyone to read the full articles.
I also encourage readers to peruse the following “honorable mention” articles: Stiell and colleagues published a “Best Practices Checklist” on behalf of the Canadian Association of Emergency Physicians pertaining to the management of acute atrial fibrillation and atrial flutter; and on behalf of the American Heart Association (in collaboration with several other major organizations), Gulati and colleagues published the 2021 Guideline for the Evaluation and Diagnosis of Chest Pain. Both publications show us how we should strive to manage atrial fibrillation and chest pain, respectively, in the emergency department for years to come.
Amal Mattu, MD, is a professor, vice chair of education, and codirector of the emergency cardiology fellowship in the department of emergency medicine at the University of Maryland, Baltimore.
A version of this article first appeared on Medscape.com.