Articles of the month (May 2018)

A monthly (ish) summary of the emergency medicine literature

Welcome to another edition of the (bi)monthly medical articles that caught my attention. As always, you can hear Casey and I ramble on about these articles and other quasi-related medical issues on the BroomDocs podcast.

Is the patient ready for intubation?

Davis DP, Hwang JQ, Dunford JV. Rate of decline in oxygen saturation at various pulse oximetry values with prehospital rapid sequence intubation. Prehospital emergency care. 2008; 12(1):46-51. PMID: 18189177

This is a retrospective look at a prospectively collected airway database. They included 87 patients with severe traumatic brain injury (GCS 8 or less) who were undergoing RSI in the pre-hospital environment. They were interested in how quickly oxygen saturation dropped after induction in this patients. The resultant curve is what we are used to, with a gradual decline at higher oxygen saturations, but a close to vertical drop off after about 93%. The number that really jumped out at me in this study was that if the patient had an oxygen saturation at 93% or lower when intubation was started, there was a 100% chance of desaturation during the intubation attempt. Starting at a level above 93% was only associated with a 6% rate of desaturation. I think this is a really good reminder of how important pre-oxygenation is, and that if you can’t get your patient to at least a 95% oxygen saturation before intubation, you probably need to use an alternative pre-oxygenation technique (such as noninvasive positive pressure ventilation).

Bottom line: Adequate preoxygenation is essential.

Davis fig 2.PNG

Heffner AC, Swords DS, Neale MN, Jones AE. Incidence and factors associated with cardiac arrest complicating emergency airway management. Resuscitation. 2013; 84(11):1500-4. PMID: 23911630

On the same topic, this is a chart review looking at 1 year’s worth of intubations (excluding patients already in cardiac arrest) in a single emergency department. The key message is that our patients are very high risk. 4.2% of patients went into cardiac arrest in the peri-intubation period, and I would contend that a significant proportion of these are preventable arrests. The patients who arrested were sicker: lower blood pressure, higher shock index, and lower oxygen saturation. Although this is retrospective data, I think it is a really good reminder that many of our patients need to be resuscitated before an intubation attempt is made, because the intubation procedure can result in cardiac arrest. You can read more in the airway series.

Bottom line: Resuscitate before you intubate


Is there a doctor on board?

Kodama D, Yanagawa B, Chung J, Fryatt K, Ackery AD. “Is there a doctor on board?”: Practical recommendations for managing in-flight medical emergencies. CMAJ. 2018; 190(8):E217-E222. PMID: 29483330

They always seem to come right at the climax of my in-flight movie, or right after I have ordered a scotch, but in flight emergencies are a common occurrence for any travelling doctor. Although most turn out to be nothing, true emergencies in the austere environment of an aircraft, with limited equipment and other passengers literally hovering over our shoulder, can be quite the ordeal. This review touches on equipment that is usually available and some policy issues are that are worth knowing if you find yourself managing an inflight emergency. I think the most important thing to know is that the pilot is ultimately responsible for the safety of the passengers and decisions to divert. That always seemed like a massive decision, and it is good to know it doesn’t sit on my shoulders. I just have to provide the best medical information I can. The other interesting tidbit that I pulled out of this is that on board oxygen only has 2 settings: 2 L/min and 4 L/min. One thing they don’t mention: some airlines will ask for documentation to prove that you are a doctor before allowing you to assist. My help has been declined in the past when I was unable to produce paperwork proving that I was a licensed physician.


A unicorn has been spotted! (A positive trial in bronchiolitis – maybe.)

Franklin D, Babl FE, Schlapbach LJ, et al. A Randomized Trial of High-Flow Oxygen Therapy in Infants with Bronchiolitis. The New England journal of medicine. 2018; 378(12):1121-1131. PMID: 29562151

This is a multicenter randomized controlled trial in infants under 12 months old with bronchiolitis requiring oxygen therapy, comparing “standard care” (only nasal prongs to a maximum of 2 L/min) to a high flow humidified nasal cannula. They included 1472 children in the analysis (out of 2217 who were eligible, so some selection bias is possible). In terms of their primary outcome, “escalation of care”, the high flow nasal cannula group looks better (12 vs 23%, p <0.0001). However, the rest of the numbers are pretty unimpressive. The primary outcome is pretty subjective, so part of the study protocol was to look at 4 variables (tachycardia, tachypnea, increasing use of oxygen, and an early warning score) that were meant to predict the need for escalation of care. The number of patients who met the pre-defined criteria for escalation was actually the same in both groups. Patients in both groups had exactly the same heart rates (162) and oxygen saturations (96%) when the decision to escalate was made, although respiratory rate was lower in the high flow group (55 vs 63%). There was no statistical difference in any of the clinical outcomes, such as hospital length of stay, ICU length of stay, or duration of oxygen therapy. More patients in the high flow group required the ICU (12 vs 9%, p=0.08), but it wasn’t statistically significant. There was no difference in adverse events. So overall, although I am sure this trial will be widely praised, I think it is at best very weakly positive based on a subjective outcome, and negative (or potentially worse) in terms of all the hard clinical outcomes measured.

Bottom line: This is not a ringing endorsement of high flow humidified nasal oxygen for bronchiolitis. I probably wouldn’t buy a machine based on this data, but if you already have one, there may be some patients for whom it is appropriate.  


X ray for epiglottitis?

Lee SH, Yun SJ, Kim DH, Jo HH, Ryu S. Do we need a change in ED diagnostic strategy for adult acute epiglottitis? The American journal of emergency medicine. 2017; 35(10):1519-1524. PMID: 28460811

Adult epiglottitis is now 4 times more common than pediatric epiglottitis in the US (20 vs 5 cases per million). Adult epiglottitis also presents differently, usually with a more subacute onset and a couple day URTI prodrome. As a result, there are more borderline cases in which we might want to use imaging, such as a soft tissue x ray of the neck, to help us with the diagnosis. This is a retrospective chart review and case control analysis looking at 91 adult patients with a confirmed diagnosis of epiglottitis (who also had a lateral neck x-ray) and 91 matched controls with normal neck x-rays. They randomized these x-rays and then had a radiologist and an emergency physician (both blinded to the purpose of the study) look at the xrays, make a whole bunch of measurements, and then call the study as normal or epiglottitis. My first lesson from this paper: there is a lot more to look for on the x-ray than just the thumb sign (they looked at 10 measurements). The epiglottis width over 6.3 mm was the best overall with an AUC of 0.87, but it really wasn’t great, with a sensitivity of 76% and specificity of 98% (and 6.3mm will be over-fit to this dataset). My second lesson from this paper: x-ray is not good enough. X-ray missed 29 of the 91 patients with confirmed epiglottitis. However, it isn’t clear to me how important all their misses were. This department seems to CT and scope a lot of patients, which might mean they are finding a healthier group of epiglottitis patients than we are used to. 7 of the 91 patients refused hospital admission, which indicates to me that they were not super sick. The one laryngoscopic image they show is way milder than they few epiglotittis patients I have seen.

Bottom line: X-ray is not good enough for ruling out epiglottitis. If you are really concerned, performing fiberoptic nasolaryngoscopy (or just calling ENT) is probably the best bet.


Assessing my capacity to judge capacity

Marco CA, Brenner JM, Kraus CK, McGrath NA, Derse AR, . Refusal of Emergency Medical Treatment: Case Studies and Ethical Foundations. Annals of emergency medicine. 2017; 70(5):696-703. PMID: 28559033

Goldfrank LR, Wittman I. Capacity? Informed Consent; Informed Discharge? Uncertainty! Annals of emergency medicine. 2017; 70(5):704-706. PMID: 28662910

It is never easy when patients disagree with us. Emotions are high and we now have to make one of the most difficult assessments in all of emergency medicine: does this patient have the capacity to decide? Of course patients are allowed to disagree with us (just think of how often we disagree with each other). However, there are many pathologies, from intoxication to encephalitis, that impair judgement and potentially limit a patient’s capacity to decide. As physicians, we always want to do what is best for our patients, and sometimes that means protecting them from themselves. This pair of papers discussed the concept of capacity in the emergency department.

The first paper uses 4 cases to discuss some of the key elements of capacity and decision making. The authors remind us that capacity is comprised of 4 elements: understanding, appreciation, reasoning, and expression of choice. An individual must be able to understand the information delivered, appreciate how it applies to his or her own situation, reason to make an appropriate decision, and communicate that choice. Capacity is task specific, meaning that a individual might have the capacity to consent to blood work, but at the same time lack capacity to consent to major surgery. Similarly, capacity is dynamic (changes with time), so a severely intoxicated patient will lack capacity at 1 am, but regain it as they sober up in the morning. Unfortunately, there are no valid tools to help us with our capacity assessments. If a patient has capacity and chooses to leave the emergency department, it is still our responsibility to make every effort to provide the best possible care, including alternative treatment options, and options for follow up. If a patient leaves against medical advice, they recommended charting:

  • Assessment of capacity
  • That you provided information about the proposed intervention, including risks of refusal
  • That you provided alternative options
  • The patient’s understanding of the risk and voluntary decision
  • Discharge instructions, including follow up
  • An invitation to return to the ED at any time

The second paper takes issue with the overly simple cases used in the first paper. The authors argue that capacity is a very complex assessment, “involving a patient’s mental status, cognitive ability, culture, education, health literacy, and ability to articulate the issues of concern.” It is essential that a physician concentrate on educating the patient and mitigating the patient’s risk as much as possible, instead of getting too focused on the process of documenting AMA. Given the complexity and importance of these decisions, they argue that they would rather stand in front of a judge to explain why they kept a patient for a few hours against their will than explain why they allowed a patient to leave who ultimately died. (I get somewhat uncomfortable with the slope that line of argument puts you on). They also emphasize that most of the time we can avoid this situation by firmly and warmly explaining why we don’t believe it is safe for them to leave.

Our privilege is to care for the critically ill and injured. When our patients reject our efforts, we must consider whether we have failed—we must decide if we are compromised in our efforts, discriminatory, insulted by disrespect, concerned about a failed relationship, or angry. We cannot allow these factors to limit our creative abilities to care for these patients who need us desperately. These are our patients; their quality care is our goal.”


Don’t try this at home kids

Bulstrode H, Kabwama S, Durnford A, Hempenstall J, Chakraborty A. Temporising extradural haematoma by craniostomy using an intraosseous needle. Injury. 2017; 48(5):1098-1100. PMID: 28238447

Obviously not science, but this case report is a fascinating read. In a patient with a large and rapidly expanding epidural hematoma who was also clinically deteriorating, they temporized the situation by using an IO drill to aspirate blood from the hematoma. I find it strange this was done in the anesthetic area just steps from the neurosurgery OR. It makes more sense to me in a remote setting trying to buy the patient enough time to be transferred to a neurosurgical centre. This patient had a good outcome, but we can’t know if it was because of this procedure, and there is no way to assess the safety of the procedure.

Bottom line: The IO gun is a tool we all have access to, keeping this is the back of your mind as an option might help in certain very rare circumstances.


That’s quite a-cute scrotum

Frohlich LC, Paydar-Darian N, Cilento BG, Lee LK. Prospective Validation of Clinical Score for Males Presenting With an Acute Scrotum. Academic emergency medicine. 2017; 24(12):1474-1482. PMID: 28833896

Calling surgeons can be scary, so emergency medicine is somewhat obsessed with developing scores, tools, rules to rule out surgical conditions such as testicular torsion and avoid that midnight phone call. This is a prospective observational study to validate the previously derived TWIST score for testicular torsion, and the quick answer is that the score isn’t good enough for clinical practice. The TWIST score is a 7 point score based on the history and physical: testicular swelling (2 points), hard testicle (2 points), absent cremasteric reflex (1 point), nausea or vomiting (1 point), and high riding testicle (1 point). They included a convenience sample of 258 males between the ages of 3 months and 18 years presenting with a chief complaint of testicular pain and/or swelling. (Presentations vary significantly between 3 month olds and 18 year olds, so the score might be expected to perform better or worse at different ages.) They excluded patients with trauma, symptoms present for greater than one week, a previous diagnosis of testicular torsion, or a known history of testicular disease and/or surgery. The score is not helpful for what we really want: ruling patients out. There were multiple misses with low scores, including a torsion in a patient with a score of 0. On the other hand, a score of 7 had a specificity of 100% (95% CI 98-100%) which might be valuable if you are trying to send the patient straight to the OR without imaging (but the sensitivity was only 21%). No aspect of the score was particularly good, meaning we can’t rely on testicular lie, cremasteric reflex, vomiting or any clinical data point to either rule in or rule out torsion. One important point: ultrasound was also not perfect, missing 3 of the 19 cases of torsion. Hear more on the SGEM.

Twist table 2.PNG

Bottom line: The rule isn’t good enough to use, but is worth reviewing as a reminder of the usual clinical presentation of torsion. The best option is still to call urology whenever there is a question.


You are not so smart – but maybe we can’t fix it

Oliver G, Oliver G, Body R. BET 2: Poor evidence on whether teaching cognitive debiasing, or cognitive forcing strategies, lead to a reduction in errors attributable to cognition in emergency medicine students or doctors. Emergency medicine journal : EMJ. 2017; 34(8):553-554. PMID: 28724568

I think Pat Croskerry deserves huge kudos from bringing cognitive biases to our attention in emergency medicine. Anyone who hasn’t read “How Doctors Think” probably should. However, as fascinating as the shortcomings of the human brain are, it isn’t clear that discussing them does us any good. This is a quick review as part of the BestBETs series that asks the question of whether teaching cognitive biases or cognitive forcing strategies actually improves decision making. There are only 2 studies, both done by Dr. Jonathan Sherbino, and both were negative. Despite being an extremely important topic, and being widely taught, there is currently no evidence that teaching cognitive biases improves clinical decision making. I discussed these studies as part of the cognitive errors series.

Bottom line: Cognitive biases are important, but it isn’t clear that a focus on individual clinicians’ thinking is the best approach to preventing errors. Instead, I think we are better off recognizing that humans are fallible and building our systems around that core principal.


Good touching among NBA players

Kraus MW, Huang C, Keltner D. Tactile communication, cooperation, and performance: an ethological study of the NBA. Emotion. 2010; 10(5):745-9. PMID: 21038960

Team performance is a core aspect of any high functioning emergency department or resuscitation. This is an interesting study that looks at touch as a marker of cooperation and trust, and how it predicts teams performance (in the National Basketball Association). Based on sociology research that indicates that touch is an important mode of communicating emotion and developing trust, these researchers hypothesized that the amount of touch displayed between basketball players might correlate with their performance. They watched NBA games, and made note of touch between players that was not directly part of playing basketball, such as “high fives, chest bumps, leaping shoulder bumps, chest punches, head slaps, head grabs, low fives, high tens, full hugs, half hugs, and team huddles”. On average, players touched each other in this was for about 2 seconds per game, or about 1/10th of a second for each minute played. They then compared the amount of touch to both individual stats and team performance. Players who touched more had better stats, even when adjusted for things like salary. Teams that touched more won more games over the course of the season, even adjusting for pre-season expectations. Teams that touched more also seemed to cooperate more. So… get out there and touch people. Or, maybe not. This is observational data, and my guess is that there are a lot of confounders here. Trust and friendship may lead to both higher levels of touching and better performance. Certain coaches or coaching systems could also be responsible for both outcomes. It is highly unlikely that you can just tell the Los Angeles Lakers to start touching each other more often and that all of a sudden they will become a playoff team. Does this apply to medicine? I don’t know. Slapping someone on the butt, while common place in the sporting world, would be a quick way to lose your job in medicine. However, recognizing the fundamental role that subtle touch (such as a hand on the forearm when breaking bad news) plays in communicating subtle emotions probably has important implications in medicine, both in our function as teams and in our interactions with patients.

Bottom line: Communication occurs in many different ways. It isn’t just words. In the emotional pressure cooker of an emergency department, it is probably important to understand that.


Bonus paper (SGEMHOP)

Gonin P, Beysard N, Yersin B, Carron P. Excited Delirium: A Systematic Review Acad Emerg Med. 2018. [article]

This is a systematic review looking at the definition, epidemiology, pathophysiology, and management of excited delirium. A full review can be found on The SGEM. This is an SGEM hot off the press paper, so if you have comments or questions for the authors, head over to the SGEM site and leave them in the comments section. The best comments will be featured in Academic Emergency Medicine.


Cheesy Joke of the Month

A woman is sitting at her deceased husband’s funeral. A man leans in to her and asks, “Do you mind if I say a word?”.

“No, go right ahead”, the woman replies.

The man stands, clears his throat, says “Plethora”, and sits back down.

“Thanks”, the woman says, “that means a lot”

 

Author: Justin Morgenstern

Emergency doctor working in the community. FOAM enthusiast. Evidence based medicine junkie. “One special advantage of the skeptical attitude of mind is that a man is never vexed to find that after all he has been in the wrong.” - William Osler

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