I took another month off, but the blog and accompanying podcast are back with what I think is an interesting collection of articles… Continue reading “Articles of the month (May 2017)”
A monthly summary of the emergency medicine literature
A monthly summary of the emergency medicine literature
I took another month off, but the blog and accompanying podcast are back with what I think is an interesting collection of articles… Continue reading “Articles of the month (May 2017)”
The best emergency medicine articles that I came across in August 2016
Welcome to another edition of my favorite emergency medicine articles of the month. Once again, there will be an accompanying podcast with the talented and insightful Dr. Casey Parker on the BroomeDocs website where we briefly discuss these articles. Continue reading “Articles of the Month (August 2016)”
My monthly summaries of the best medical literature that I have come across
Every month I select the best medical articles I have read and provide brief summaries and critical appraisals. Here are this month’s articles:
Kudenchuk PJ et al. Amiodarone, Lidocaine, or Placebo in Out-of-Hospital Cardiac Arrest. NEJM 2016. PMID: 27043165
There is a lot that could be said about this paper. It was a large, randomized, double-blind placebo controlled trial that included 3026 patients in out of hospital cardiac arrest. It compared amiodarone to lidocaine to placebo. The simplistic answer: there was no difference. I am tempted to stop there, because I never thought amiodarone helped, but the data might be a little more granular than that. For the primary outcome of survival to hospital discharge, the numbers were: 24.4% with amiodarone, 23.7% with lidocaine, and 21.0% with placebo. There was no statistically significant difference, as the trial was powered to find a 6.3% difference, but the absolute difference of 3.4% in survival to discharge could be clinically important. Unfortunately, treatment with these antiarrhythmics is not without harm. More patients in both the amiodarone and lidocaine groups were admitted to hospital. That sounds great on the surface, but the last thing any patient wants is to spend their final days as a vegetable in the ICU. If they aren’t going home at the end of that ICU stay, I think this is an important harm to consider.
Note: Keep an eye open for a future episode of EMCases Journal Jam, as I will be speaking with a few of the authors to see how they interpret this data.
Laan DV et al. Chest Wall Thickness and Decompression Failure: A systematic Review and Meta-Analysis Comparing Anatomic Locations in Needle Thoracostomy. Injury 2015 [Epub Ahead of Print]. PMID: 26724173
This is a systematic review and meta-analysis that looked at a total of 28 studies that attempted to determine the best location for a needle decompression of pneumothorax. 15 studies were imaging based studies that looked at chest wall thickness, and found that the mean total chest wall thickness was 4.3cm in the traditional midclavicular 2nd intercostal space, 4.0 cm in the 5th intercostal space (anterior axillary line), and 3.4 cm in the 5th intercostal space (mid axillary line) (Not statistically different with p=0.08). 13 studies looked at at how frequently a 5cm angiocath failed to reach the pleural space, and the results were: 38% with the traditional mid clavicular 2nd intercostal space approach, 31% with the 5th intercostal space (anterior axillary line), and 13% with the 5th intercostal space (mid axillary line) (p=0.01).
White JM, Braude DA, Lorenzo G, Hart BL. Radiographic evaluation of carotid artery compression in patients with extraglottic airway devices in place. Academic emergency medicine : official journal of the Society for Academic Emergency Medicine. 22(5):636-8. 2015. PMID: 25903385
I love LMAs for cardiac arrest. No matter how slick the operator, intubation takes time, can interfere with compressions, and distracts from the real issue. LMAs are quick, easy, and provide everything we need for the initial resuscitation of cardiac arrest patients. However, a pig study in 2012 raised the concern that LMAs might compress the carotid arteries. Luckily, most humans don’t look like pigs. This is a cohort study of 17 trauma patients with supraglottic airway devices in place who were having CT imaging of their neck. None of the patients had any radiographic evidence of compression of their carotid arteries. This isn’t the strongest paper you will ever read, but nor was the study that raised these concerns in the first place.
Tieder JS, Bonkowsky JL, Etzel RA et al. Brief Resolved Unexplained Events (Formerly Apparent Life-Threatening Events) and Evaluation of Lower-Risk Infants. PEDIATRICS. 137(5):e20160590-e20160590. 2016. [free full text]
ALTE no longer exists. We now have BRUEs or brief resolved unexplained events. This is a clinical practice guideline from the American Academy of Pediatrics on the topic. Aside from the name change, here are some of my take-aways:
Au AK, Steinberg D, Thom C. Ultrasound measurement of inferior vena cava collapse predicts propofol-induced hypotension. The American journal of emergency medicine. 2016. PMID: 27090394
This is a prospective observational study of a convenience sample of 40 patients getting propofol for induction of anesthesia for elective surgery. They used ultrasound to measure the collapse of the IVC pre-propofol, and calculated the percentage collapse as: (max IVC size – min IVC size)/max IVC size. Patients with IVC collapse >50% had more propofol-induced hypotension than those without (76% versus 39%, p=0.02). This would result in a sensitivity of 67%, a specificity of 77%, a positive predictive value of 71%, and a negative predictive value of 74%. None of those values is enough to rule-in or rule -out on their own, but they might be helpful as part of an overall assessment. Of course, isolated brief hypotension after propofol might not be all that relevant as an outcome. Also, the doses of propofol used here were pretty high (mean of 2.4mg/kg IV push) and these were healthy, elective surgery patients, so there are multiple reasons these numbers might not extrapolate the the ED.
Silverton N, Youngquist S, Bledsoe J, Mallin M, Barton E. 71: Awake “Tomahawk” Video Laryngoscopy. Annals of Emergency Medicine. 56(3):S24-. 2010. [article]
This paper describes a technique I have found very useful in the past. Talking recently with my friend Dr. Joey Newbigging, I realized this might be new (and hopefully useful) for some people. Basically, while the patient is sitting upright, after providing some topical anesthetic, you insert the glidescope into their mouth using a “tomahawk” grip. Basically that means you hold the handle upside down, so the blade is coming out of the top of your hand. If that descriptions didn’t help, check out this blog post with pictures. I find it very useful for visualizing fish bones, especially when the fiberoptic scope is dirty, but also because it also allows for instrumentation of the airway. Using this approach, these authors were able to get grade 2 views of the cords in 94% of the awake, healthy volunteers.
Weant KA, Weant MP. Safety and efficacy of glucagon for the relief of acute esophageal food impaction. American journal of health-system pharmacy : AJHP : official journal of the American Society of Health-System Pharmacists. 69(7):573-7. 2012. PMID: 22441787
In this review of IV glucagon for the treatment of esophageal food bolus, they identified only two studies that had a control group. Both were negative, with with dislodgement rate actually being lower (but not statistically so) with glucagon in one of the two trials.
Bodkin RP, Weant KA, Baker Justice S, Spencer MT, Acquisto NM. Effectiveness of glucagon in relieving esophageal foreign body impaction: a multicenter study. The American journal of emergency medicine. 2016. PMID: 27038694
This study is retrospective – but given how little evidence we have for glucagon, it might be worth looking at. They retrospectively identified 127 patients who were given 133 doses of glucagon (median dose 1mg IV) for esophageal food bolus, as well as a control group that was not given glucagon. Resolution occurred in 14% of patients given glucagon, which wasn’t statistically different from the 10% resolution seen with nothing. Vomiting occurred in 13% of patients given glucagon.
You can read more here: A Closer Look at Glucagon for the Foreign Body
Kannikeswaran N, Lieh-Lai M, Malian M, Wang B, Farooqi A, Roback MG. Optimal dosing of intravenous ketamine for procedural sedation in children in the ED—a randomized controlled trial. The American Journal of Emergency Medicine. 2016. [article]
This is a prospective, double-blind, RCT of 125 children aged 3-18 years comparing 3 different doses of ketamine (1, 1.5, and 2mg/kg). Not surprisingly, re-dosing was higher in the 1mg/kg group (16% vs 2.9% and 5%), but I’m not sure that is an important outcome. There weren’t any differences in sedation scores, sedation duration, or adverse events. Physician satisfaction was lower with 1mg/kg (80% vs 94% and 97%). Perhaps the most important numbers were from phone follow-up (although they did lose some patients). Vomiting: 10% with 1mg/kg, 12% with 15mg/kg, and 20% with 2mg/kg. Recall of the painful procedure: 19% with 1mg/kg, 7% with 15mg/kg, and 7% with 2mg/kg.
This review looked to answer the question: what is the best treatment for head lice? They found 2 RCTs comparing permethrin with dimeticone (a silicone-based product that suffocates lices). They conclude that dimeticone is superior to permethrin, with 1 extra cure for every 3 to 4 patients treated. Dimeticone also seems to be cheaper.
Titulaer MJ et al. Treatment and prognostic factors for longterm outcome in patients with anti-NMDA receptor encephalitis: an observational cohort study. Lancet Neurol. 2013 Feb;12(2):157-65. PMID: 23290630 [free full text]
If you haven’t heard of or seen anti-NMDA receptor encephalitis, this prospective observational trial has some good take away points.
Rainer TH, Cheng CH, Janssens HJ. Oral Prednisolone in the Treatment of Acute Gout: A Pragmatic, Multicenter, Double-Blind, Randomized Trial. Annals of internal medicine. 164(7):464-71. 2016. PMID: 26903390
This is a multicenter, double blind RCT of 416 adult patients presenting to the ED with gout, comparing indomethacin to prednisolone. There really weren’t any differences, either in effectiveness or adverse events. Pain was decreased by 2.5/10 at rest and 4.5/10 with activity with both treatments. About 40% of each group had minor adverse events. Unfortunately, many of the side effects that make me want to avoid NSAIDs (primarily in older patients) are also present with steroids, so I am not sure when to choose one over the other. (I would love to see some single dose dexamethasone studies for gout, just for ease of dosing.)
One of the most common requests I encounter from nursing is for prophylactic anti-emetics when I prescribe opioids. Understandable, considering that by the time the patient vomits, I am generally off somewhere else doing something more exciting. But do they work? Let’s look at a few papers:
Lambie B, Chambers J, Herbison P. The role of prophylactic anti-emetic therapy in emergency department patients receiving intravenous morphine for musculoskeletal trauma. Emerg Med Australas. 11(4):240-243. 1999. [article]
RCT of 214 emergency department patients getting intravenous morphine for analgesia, randomized to either metoclopramide 10mg IV or placebo prior to the morphine. 1.9% of the placebo group vomited as compared to 5.4% in the metoclopramide group (p=0.0009). Yeah – more vomiting in the metoclopramide group!
Again, this is a RCT of 259 emergency department patients getting morphine for pain, comparing metoclopramide to placebo. There was no statistically significant difference in nausea and vomiting between the groups (1.6% with metoclopramide and 3.7% with placebo).
Simpson PM, Bendall JC, Middleton PM. Review article: Prophylactic metoclopramide for patients receiving intravenous morphine in the emergency setting: a systematic review and meta-analysis of randomized controlled trials. Emergency medicine Australasia : EMA. 23(4):452-7. 2011. PMID: 21824312
This is a systematic review and meta-analysis looking at whether prophylactic metoclopramide prevents vomiting from opioids. The conclusion is that there was no difference between metoclopramide and placebo.
As far as I am aware, there are no studies looking at prophylactic ondansetron.
Sussman G, Shurman J, Creed MR. Intravenous ondansetron for the control of opioid-induced nausea and vomiting. International S3AA3013 Study Group. Clinical therapeutics. 21(7):1216-27. 1999. PMID: 10463519
This study takes a different approach: it waits for nausea to develop first, before trying to treat it. It is a randomized, double blind, placebo controlled trial comparing placebo, ondansetron 8mg and ondansetron 16mg IV in patients who developed nausea after being given an opioid. Of 2574 patients given opioids, 520 developed nausea/vomiting and were therefore included in the study. Resolution of N/V with ondansetron was significantly better than with placebo (45.7% with placebo, 62.3% with 8mg, and 68.7% with 16mg.)
Isbister GK, Calver LA, Downes MA, Page CB. Ketamine as Rescue Treatment for Difficult-to-Sedate Severe Acute Behavioral Disturbance in the Emergency Department. Annals of emergency medicine. 2016. PMID: 26899459
This is a subgroup analysis of a prospective RCT comparing droperidol to midazolam. It looks at 49 patients with acute agitation who had already not responded high dose sedatives (most commonly a total of 20mg of droperidol) and were given ketamine. 44 of the 49 were adequately sedated with ketamine, and 4 of the 5 not sedated were given less than 200mg ketamine IM. There were only 3 adverse events: 2 patients vomited, and 1 had his oxygen saturation drop to 90%. This obviously isn’t practice changing in itself, but ketamine is a very interesting option for sedating agitated patients because of its ability to keep respiratory drive and airway reflexes in tact.
I’m going to have to cheat this month – there is just too much excellent stuff out there.
First, no matter what your level of expertise, some ECGs are so important that we need to continuously review examples to maintain our pattern recognition skills. Hyperacute T-waves are an example an essential finding that is easily overlooked without practice. Dr. Steve Smith had 2 great posts on this ECG finding this month: here and here.
Although I am sure that everyone is aware the moment Scott Weingart posts anything, if you haven’t heard his talk on OODA loops yet, it is a must listen to understand clinical reasoning in the resuscitation room.
I had to stop listing SMACC talks in this section, because they would have just dominated every month. Soon, Josh Farkas might be in the same category. For now, he had two amazing posts that immediately impacted my practice: first, he suggests an innovative way of documenting a difficult airway, using the allergy list; second, he provides some really great insight into vasopressor use in septic shock.
Last, but definitely not least, Choosing Wisely Canada has developed a number of useful implementation guides, such as “Bye-Bye, PPI”
I remember the last thing my grandpa said to me before he kicked the bucket.
He said “Hey, how far do you think I can kick this bucket?”
An approach to the initial management of the asthma patient presenting to the emergency department in extremis
A 16 year old female with a history of severe asthma is brought to your community emergency department after a week of respiratory symptoms that have suddenly become much worse. She has been admitted to hospital 4 times this year, including one visit to the ICU. Her respiratory rate is 45 and she is using every accessory muscle she has, but she doesn’t appear to be moving much air. In fact, her lungs are silent to auscultation. She looks tired and the monitor shows her vitals as a heart rate of 140, blood pressure of 99/60, and an oxygen saturation of 88%…
A monthly collection of the most interesting emergency medical literature I have encountered
Shahrami A et al. Comparison of therapeutic effects of magnesium sulfate vs. dexamethasone/metoclopramide on alleviating acute migraine headache. J Emerg Med 2015; 48(1): 69-76. PMID 25278139
In this RCT, they compared IV magnesium (1 gram) to the combination of metoclopramide 10mg IV and dexamethasome 8mg IV. Magnesium was more effective at 20min, 1 and 2 hours. I would note, that although metoclopramide is what we generally have to use now because of drug shortages or silly rules, prochlorperazine (Stemetil) and droperidol are both better for migraine. Also, previous studies of metoclopramide in migraine have used a 20mg dose, although 10mg is what tends to be ordered.
The ProMISe trial. Mouncey et al. Trial of Early, Goal-Directed Resuscitation for Septic Shock. NEJM. 2015 (Ahead of print). PMID: 25776532
This is the third and final large trial of early goal directed therapy for septic shock, and shockingly it tells us pretty much the same thing the first two did: EGDT adds nothing to usual care. This is an open label, multi-center RCT from the UK with a total of 1260 patients. Patients were randomized to receive the classic EGDT protocol or ‘usual care’. There was no difference in mortality, (29% at 90 days). Of course, ‘usual care’ may look a lot more like EGDT than it used to.
Proano L et al. Cardiology electrocardiogram overreads rarely influence patient care outcome. Am Jour Emerg Med 2014;32(11):1311-14. PMID: 25200503
This is a retrospective review at a single teaching hospital over 21 months, with 38,490 ECGs reviewed. Of the 16,011 patients that were discharged, 22 patients required follow up for discordant readings (0.1%). Of those 22, after review only 2 were determined to require a change in management. The remainder were considered ‘non specific’ or the ED doc turned out to be right. Of the 2 with changed management, one was for ‘possible ACS’ who ultimately had a completely negative workup. The other was a missed atrial flutter, but nothing changed about their management except also getting a negative workup.
Sanghavi BS et al. Outcomes After Out-of-Hospital Cardiac Arrest Treated by Basic vs Advanced Life Support. JAMA Intern Med. 2015;175(2):196-204. PMID: 25419698
We already know this, because it has been over a decade since OPALS (in Ontario) proved that ACLS doesn’t work. This is an observational cohort study of American medicare patients with out of hospital cardiac arrest, based on whether they were treated by an ACLS or BLS crew. Survival to hospital discharge was better with BLS (13.1% vs 9.2%). Survival at 90 days was better with BLS (8.0% vs 5.4%).
McMullan J et al. Airway management and out-of-hospital cardiac arrest outcome in the CARES registry. Resuscitation 2014, 85(5):617-622. PMID: 24561079
This is a retrospective registry review of 10,691 out of hospital cardiac arrests that demonstrated that patients that did not have advanced airways placed during the initial resuscitation were more likely to survive to hospital discharge with good neurological outcomes (OR 4.24 95% CI 3.26-5.20). The use of supraglottic airways was associated with worse outcomes than endotracheal intubation. Of course, these are just associations in a very complex scenario with multiple confounders.
Shif Y et al. What CPR means to surrogate decision makers of ICU patients. Resuscitation 2015 (In print). PMID: 25711518
This is qualitative research on communication and understanding of CPR by surrogate decision makers in the ICU. (I love this stuff, but probably mostly because my master’s was based in qualitative research and communication. Realistically, this study probably just states the obvious.) Less than half of surrogate decision makers identified cardiac arrest as the indication for CPR. Only 8% could identify the major components of CPR (although the technical details probably don’t matter that much.) Mostly importantly, 72% thought that the survival rate post CPR is greater than 75%.
Cohen L et al. The effect of ketamine on intracranial and cerebral perfusion pressure and health outcomes: a systematic review. Annals of Emergency Medicine 2015; 65(1):45-51. PMID: 25064742
This systematic review found a total of 10 studies, all in the ICU or OR as they were actually measuring ICPs. Mostly ketamine didn’t change ICP or CPP. In two studies, ICP actually decreased with ketamine. In two studies it did go up, but by 2-4 mmHg, so clinically meaningless. There were no changes in neurological outcomes, ICU length of stay, or mortality.
Bottom line: Ketamine is a wonder drug that can do anything, possibly even solve our boarding crisis, so go ahead and use it whenever you want.
Waldman N et al. Topical tetracaine used for 24 h is safe and rated highly effective by patients for the treatment of pain caused by corneal abrasions: a double-blind, randomized clinical trial. Acad Emerg Med 2014; 21:374-382. PMID: 24730399
This is a prospective double blind RCT in which patients with corneal abrasions were allowed to use tetracaine 1% q30min PRN for pain after simple corneal abrasions (versus saline placebo). This is not the first study to look at this, and the dogma is based on a handful of ridiculous case reports. There were no complications (to be fair 116 patient trial is not big enough to be sure it is safe.) It is a weird trial, because pain scores didn’t go down, but patients were more satisfied with their care if they were given tetracaine.
Jang TB etl al. Bedside ultrasonography for the detection of small bowel obstruction in the emergency department. Emerg Med J. 2011;28(8):676-8. PMID: 20732861
A prospective study of 76 patients with suspected SBO, all of who had a CT scan done. Residents were given a 10 training session on using bedside ultrasound to assess for bowel obstruction. The bedside ultrasound had a sensitivity of 91% and a specificity of 84% compared to the CT gold standard. Compare that to abdominal plain films, which had a sensitivity of 46% and a specificity of 67%.
Felton at al. 13-Year-Old Girl With Recurrent, Episodic, Persistent Vomiting: Out of the Pot and Into the Fire. Pediatrics 2015 (Ahead of print). PMID: 25733759
OK, this is only a case report and only gets in because I have an axe to grind. I hate urine toxicology screens and believe they should never be ordered in the ED. But it does raise an interesting tidbit to keep in mind: apparently pantoprozole can cause a false positive urine tox screen for marijuana.
Godwin SA et al. Clinical policy: procedural sedation and analgesia in the emergency department. Ann Emerg Med. 2014;63(2):247-58. PMID: 24438649
As part of the ACEP clinical policy process, they did a systematic review. They found 5 studies that cover thousands of patients, and found no evidence that fasting decreased aspiration or other adverse events. The official policy is “Level B: Do not delay procedural sedation in adults or pediatrics in the ED based on fasting time. Preprocedural fasting for any duration has not demonstrated a reduction in the risk of emesis or aspiration when administering procedural sedation and analgesia.”
Duncan R and Thakore S. Decreased Glasgow Coma Scale does not mandate endotracheal intubation in the emergency department. J Emerg Med 2009;37(4):451-5. PMID: 19272743
An older paper that came across my desk that I think is worth including because I know practice varies wildly in this regard, and I have debated this point with multiple folks. This is a prospective study of 73 overdose patients with decreased LOC who were watched, not intubated (GCS ranged from 3 to 14). No patient with a GCS under 8 worsened, required intubation, or aspirated.
Ibrahim I et al. Arterial Puncture Using Insulin Needle Is Less Painful Than With Standard Needle: A Randomized Crossover Study. Acad Emerg Med 2015 (Ahead of print). PMID: 25731215
Although I don’t think ABGs are very helpful most of the time, you might want to calculate an A-a gradient or something some day. This was a randomized study of healthy volunteers comparing a standard 23 gauge to an insulin needle for arterial stabs. Not surprisingly, both pain and complications were lower with the smaller needle. However, hemolysis went up, so not great if you really want a K – but why do you want to know the arterial K?
Goldstein JN et al. Four-factor prothrombin complex concentrate versus plasma for rapid vitamin K antagonist reversal in patients needing urgent surgical or invasive interventions: a phase 3b, open-label, non-inferiority, randomised trial. Lancet 2015 (ahead of print). PMID: 25728933
This is an open label RCT of 181 patients comparing PCC (Beriplex) to FFP before an ‘urgent surgery or procedure’. Based on rated ‘effective hemostasis’ being achieved in 90% of the PCC group and 75% of the FFP group, the authors conclude that PCC is superior to FFP. Sadly, this article appears to have been written directly by the drug company (if you read the funding statement), had protocol changes as it went, and relies on reporting of a surrogate end point. Despite all that, the treatments were actually identical. Difference in surgical blood loss between the two groups: 12 ml. Total number of units of blood transfused – identical in both groups.
Rahimi RS et al. Lactulose vs polyethylene glycol 3350-electrolyte solution for treatment of overt hepatic encephalopathy: the HELP randomized clinical trial. JAMA Intern Med 2014; 174(11):1727-1733. PMID: 25243839
This is a small RCT comparing PEG 3350 to lactulose for patients with hepatic encephalopathy. PEG 3350 resulted in more rapid resolution of symptoms than lactulose.
Du Toit et al. Randomized trial of peanut consumption in infants at risk for peanut allergy. NEJM 2015; 372:802-813. PMID: 25705822
This is the RCT to show anyone who ever tells you that there some are things we just can’t study. They took 640 children at risk of developing peanut allergy because they already had an egg allergy or severe eczema and randomized them to either eat or not a peanut based snack. The results are relatively astounding. If you didn’t have a positive skin test at the beginning of the study, being exposed to peanuts decreased your chance of developing a peanut allergy by 12% (NNT = 8). If you had a positive skin test at the outset, being exposed to peanut protein decreased your allergy rate by 25% (NNT =4)!
I went to a zoo recently, and the only animal there was a dog…
It was a shitzu