Articles of the month (June 2017 – #dasSMACC edition)

This month’s articles are a little special. Usually, I pick out the articles that catch my eye, but it’s easy to imagine that my biases filter out a lot of interesting medical literature. As there were a number of experts descending on Berlin this month for SMACC, Casey Parker and I invited a few people to suggest a paper and discuss it with us over a beer for our podcast. The conversation was great, and can be found here. These are the articles that were picked:

Continue reading “Articles of the month (June 2017 – #dasSMACC edition)”

First10EM on theSGEM!

I was honoured to be invited on The Skeptics Guide to Emergency Medicine this week to discuss the FLORALI trial with Ken Milne.

The episode is: SGEM#135: The Answer My Friend is Blowin’ in your Nose – High Flow Nasal Oxygen

 

I had previously mentioned this paper in the May 2015 edition of my Articles of the Month.

My Bottom line: High flow nasal oxygen seems to be as good as NIPPV or facemask oxygen (in this select group of patients). This is enough for me to try this with alert pneumonia patients who don’t obviously need intubation.

I personally like high flow nasal oxygen for a lot of these patients, because it seems to be more comfortable, allow for easier communication, and provides the option of oral intake. This study certainly is not enough to justify the expense of purchasing one of these units if you don’t already have one. However, if there is already one in your department, I say give it a trial.

Two major questions remain, in my mind:

  1. In these hypoxic patients, when should we be intubating? Does placing a patient on high flow nasal oxygen simply delay the inevitable intubation? Might that lead to worse outcomes?
  2. Was this study underpowered to show a benefit? They powered the study to show a 20% decrease in intubation and the study was negative. However, the point estimates were better for high flow nasal oxygen in all categories. Also, a secondary outcome of mortality at 90 days was statistically better in the high flow group. We need more trials to determine the real effect of high flow nasal oxygen.

For a proper skeptical take on this paper, go listen to the episode!

 

Reference

Frat JP, Thille AW, Mercat A, et al. High-Flow Oxygen through Nasal Cannula in Acute Hypoxemic Respiratory Failure. N Engl J Med. 2015. PMID: 25981908

Articles of the month (May 2015)

A monthly collection of the most interesting emergency medical literature I have encountered

Here are my favorite reads from this month. It is a little longer than usual, because apparently what I enjoy doing while sitting pool-side in paradise is catching up on the medical literature. I am sure there is room in the next iteration of the DSM for that.

 

Myth: Wound eversion magically eliminates scarring

Kappel S, Kleinerman R, King TH, et al. Does wound eversion improve cosmetic outcome?: Results of a randomized, split-scar, comparative trial. J Am Acad Dermatol. 2015;72:(4)668-73. PMID: 25619206

This is a prospective, randomized trial of post-op skin surgery patients where they closed half of the wound using wound eversion and the other half using basic planar approximation. The patients and 2 assessors were blinded and there was no significant difference in appearance at 3 or 6 months. This is in clean surgical wounds, so external validity to the ED is questionable. However, the authors looked for science supporting the dogma of wound eversion, and not surprisingly: there is none.

Bottom line: This is enough for me to stop dogmatically teaching wound eversion – though with only one study, I am always ready to change my mind.


“Therapeutic” hypothermia

Mark DG, Vinson DR, Hung YY, et al. Lack of improved outcomes with increased use of targeted temperature management following out-of-hospital cardiac arrest: a multicenter retrospective cohort study. Resuscitation. 2014;85:(11)1549-56. PMID: 25180922

A retrospective, before and after study of 1119 patients in a system where therapeutic hypothermia for out of hospital cardiac arrest was implemented in 2009. Despite the fact that you would expect improved outcomes just because of improved medical care over the half decade the study ran, there was no difference in mortality or neurologic outcomes whether or not you were cooled.

Bottom line: Thanks to TTM, we already know that cooling is not necessary. We should remember that fever avoidance is currently only a theory without significant evidence basis.


Kids don’t like being cold either

Moler FW, Silverstein FS, Holubkov R, et al. Therapeutic Hypothermia after Out-of-Hospital Cardiac Arrest in Children. N Engl J Med. 2015;372:(20)1898-1908. PMID: 25913022 

You probably would have been fine applying the TTM data to children, as they are just little adults, but we now have some pediatric specific data. This is a multicentre RCT of pediatric (2 days to 18 years) out of hospital cardiac arrest, comparing 33.0 with 36.8 degree Celsius targets. As you might expect, there was no difference in survival or functional outcomes up to one year. However, the raw numbers were better in the hypothermic children, despite being non-statistically significant.

Bottom line: There is no reason to put kids on ice outside of the context of further clinical trials.


Rate control in atrial fibrillation cage match: the cardiology approach (beta blockers) versus the emergency medicine approach (calcium channel blockers)

Martindale JL, et al. β-Blockers versus calcium channel blockers for acute rate control of atrial fibrillation with rapid ventricular response: a systematic review. Eur J Emerg Med. 2015;22:(3)150-4. PMID: 25564459

This is a systematic review of calcium channel blocker versus beta blockers for acute rate control of atrial fibrillation. They could only find 2 quality studies, which were very small. In these studies, diltiazem was better than metoprolol (RR 1.8 95% CI 1.2-2.6) for rate control.

Bottom line: The very limited evidence seems to fit with clinical experience: calcium channels blockers are more likely to get patients controlled in the ED.


The toughest question in the resus room? Maybe if a.fib is the cause of or the result of hemodynamic instability

Scheuermeyer FX, Pourvali R, Rowe BH, et al. Emergency Department Patients With Atrial Fibrillation or Flutter and an Acute Underlying Medical Illness May Not Benefit From Attempts to Control Rate or Rhythm. Ann Emerg Med. 2015;65:(5)511-522.e2. PMID: 25441768

This is a retrospective chart review (well done, but a chart review) of 416 patients with atrial fibrillation and an acute medical illness, out of British Columbia. They compared those patients who had their atrial fibrillation actively managed, versus those in whom the focus was only in treating the underlying condition. No one died in this study. Patients who had either rate or rhythm control had significantly increased rates of major adverse events, primarily increased requirement for pressors and increased intubations.

Bottom line: In sick medical patients who happen to have atrial fibrillation, focus on basic resuscitation over rate/rhythm control.


The new angioedema meds

Bas M et al. A randomized trial of icatibant in ACE-inhibitor-induced angioedema. New England Journal of Medicine. 2015;372(5):418-25. PMID: 25629740

This is one of a few new, very expensive treatments for hereditary angioedema. It is a selective bradykinin B2 receptor antagonist. This was a phase 2 RCT of 30 patients who either received Icatibant or standard therapy of steroids and anti-histamines for patients with ACE inhibitor induced angioedema. The icatibant group responded quicker (8 hours versus 27 hours) and had more complete resolution of their symptoms. The biggest concern with this study (aside from the tiny size and industry involvement) is that, although the standard therapy group probably represents usual care, ideal care might involve use of FFP instead.

Bottom line: In a very small study, icatibant seems to decrease angioedema a lot quicker than ‘usual care’.


Lots of Os up the nose

Frat JP, Thille AW, Mercat A, et al. High-Flow Oxygen through Nasal Cannula in Acute Hypoxemic Respiratory Failure. N Engl J Med. 2015. PMID: 25981908

This is a multi-centre randomized, open label study of high flow, humidified nasal oxygen, versus standard oxygen face mask, versus non-invasive positive pressure ventilation in adult, hypoxic patients. (CHF and exacerbations of asthma or chronic respiratory failure was excluded, so in other words this is primarily pneumonia patients.) There was no difference in their primary outcome of need for intubation, although they powered the study to detect a 20% difference, which is probably larger than the clinically important difference. This biggest news is that 90 day mortality was decreased in the high flow oxygen group (12%, versus 23% with standard oxygen and 28% in NIPPV), but this is a secondary outcome so should be interpreted with caution.

Bottom line: High flow nasal oxygen seems to be at least as good as NIPPV or facemask oxygen (in this select group of patients). This is enough for me to try this with alert pneumonia patients who don’t obviously need intubation.


More evidence PPIs aren’t completely safe

Antoniou T et al. Proton pump inhibitors and the risk of acute kidney injury in older patients: a population-based cohort study. CMAJ Open 2015;3(2):E166-71. (Free full text here)

Using the Ontario Drug Benefit database, these authors compared the cohort of patients with newly prescribed PPIs with a propensity matched group as a control. They excluded anyone also prescribed known nephrotoxic drugs, or with basically any other renal risk factors. People on PPIs were more likely to develop acute kidney injury, with a hazard ratio of 2.52 (95% CI 2.27-2.79). Out of 290,000 patients studied, 1787 were admitted to hospital with AKI – about 8 more than controls for every 1000 patient years on PPIs.

Bottom line: No medication is without side effects, but we treat some like they are water. Early studies will always emphasize benefits and downplay harms.


You don’t need fancy lenses and mirrors to see the retina

Vrablik ME et al. The diagnostic accuracy of bedside ocular ultrasonography for the diagnosis of retinal detachment: a systematic review and meta-analysis. Ann Emerg Med 2015; 65(2):199-203. PMID: 24680547

This meta-analysis attempted to determine the accuracy of ultrasound for diagnosis of retinal detachment in the hands of emergency physicians. In population with a prevalence of detachment between 15% and 38%, they found a sensitivity of ultrasound of 97-100% and a specificity of 83-100%. Of course, these studies are often done with experienced ultrasonographers or after specific training.

Bottom line: I think this definitely has a place in the ED.

Bonus: This castlefest lecture is a great resource for ocular ultrasound, with free CME


A little more diagnostic technology: iPhone otoscopes

Richards JR, Gaylor KA, Pilgrim AJ. Comparison of traditional otoscope to iPhone otoscope in the pediatric ED. Am J Emerg Med. 2015. PMID:  25979304

These authors compared a traditional otoscope with a new one that attaches to your iphone and gives you a video display. There was reasonable agreement between the new one and the old one, although residents and attendings still disagreed about the findings a lot. They claim that the iPhone scope changed the final diagnosis a number of times, but without a clear gold standard I wouldn’t focus on that result.

Bottom line: I am not sure how important it is to treat anything they found here, which limits the value of the tool – but this could be a great way to teach students otoscopy.


Can the D-Dimer be improved? (Well, it can’t get any worse, can it?)

Jaconelli Y and Crane S. Towards evidence based emergency medicine: best BETs from the Manchester Royal Infirmary. BET 2: Should we use an age adjusted D-dimer threshold in managing low risk patients with suspected pulmonary embolism? Emerg Med J 2015;32(4):335-7. PMID: 25804861

This is a systematic review (published before last month’s paper, and so not including it) that found 13 papers addressing the use of an age adjusted d-dimer (less than age x 10). Most of the studies were retrospective, so not of high quality. The authors conclusion is “In older patients suspected of having a PE, with a low pretest possibility, an age-adjusted D-dimer increases specificity with minimal change in the sensitivity, thereby increasing the number of patients who can be safely discharged without further investigations.”

Bottom line: It is looking like the age adjusted d-dimmer in low pre-test probability patients will result in a post-test probability below the test threshold, while increasing specificity.


Speaking of PE testing, the CTPA is not a perfect test

Miller WT, Marinari LA, Barbosa E, et al. Small Pulmonary Artery Defects Are Not Reliable Indicators of Pulmonary Embolism. Ann Am Thorac Soc. 2015. PMID: 25961445

In this study, they took all of the CT scans that were read as positive for PE in one radiology system, and had the scan review by 4 subspeciality thoracic radiologists. 15% of scans read as showing a subsegmental PE by community radiologists were thought to be false positives by the specialists. Another 27% were thought to be indeterminate. This only represents disagreement among radiologists and not the inherent false positives of the test itself.

Bottom line: A positive CT scan is not an objective finding. Before subjecting patients to lifelong anticoagulation, a second opinion on the read might be warranted.


PEs come from the legs – those IVC filters make sense, right?

Mismetti P, Laporte S, Pellerin O, et al. Effect of a retrievable inferior vena cava filter plus anticoagulation vs anticoagulation alone on risk of recurrent pulmonary embolism: a randomized clinical trial. JAMA. 2015;313:(16)1627-35. PMID: 25919526

Prosecptive RCT with blinded outcome assessors, but unblinded patients and treating physicians, randomized 399 patients with PE plus a DVT plus a marker of severity to either anticoagulation alone or anticoagulation plus a retrievable IVC filter. Recurrent PE occurred in 3% of the filter group (all fatal) and 1.5% of the no filter group (2 of 3 fatal) for a non statistically significant relative risk of 2.0 (95% CI 0.51 – 7.89).

Bottom line: IVC filter don’t decrease the rate of PE in patients than can be anticoagulated.


Medications don’t cure kidney stones

Pickard R et al. Medical expulsive therapy in adults with ureteric colic: a multicentre, randomised, placebo-controlled trial. Lancet. 2015. PMID: 25998582

Flomax was pushed for renal stones based on a number a small studies with horrible methods and a few meta-analyses of those horrible studies. There has already been one large RCT with excellent methods demonstrating that Flomax doesn’t work. This should be the nail in the coffin. This is a multicentre placebo controlled RCT of 1167 adult patients with CT confirmed renal stones. They were randomized to either tamsulosin 0.4mg, nifedipine 30mg, or placebo. There was no difference between any of the groups in the number of patients requiring urologic intervention. (About 80% of the patients passed spontaneously, and 20% required an intervention in all groups.)

Bottom line: There is no role for medical expulsive therapy in renal colic.


Antibiotics don’t work for diverticulitis? Is nothing sacred?

Shabanzadeh DM, Wille-Jørgensen P. Antibiotics for uncomplicated diverticulitis. Cochrane Database Syst Rev. 2012;11:CD009092. PMID: 23152268

This is a Cochrane systematic review that was able to identify 3 RCTs looking at the use of antibiotics for uncomplicated diverticulitis. Only one compared antibiotics to no antibiotics, the other two compared different types and courses of antibiotics. There was no difference in any of the regimens. In other words, no antibiotics was the same as antibiotics.

Bottom line: Not enough to change my practice, but it is good to know that we have minimal footing to our current practice.


Antibiotics in appendicitis? The right side of the bowel is different from the left, right?

Varadhan KK, Humes DJ, Neal KR, Lobo DN. Antibiotic therapy versus appendectomy for acute appendicitis: a meta-analysis. World J Surg. 2010;34:(2)199-209. PMID: 20041249

This meta-analysis concludes surgery may have a lower risk of complications than antibiotics (RR 0.43 95% CI 0.16-1.18). A little more than 30% of patients treated with antibiotics will actually require surgery. The authors seem to think biases in current study favour the antibiotics group, so real outcomes might be worse.

Bottom line: We don’t really get to make this decision anyway, but surgery is probably still the gold standard.


One last one on antibiotics: If you are going to treat with oral (which you probably should in most cases) don’t give a dose IV in the department

Haran JP, Hayward G, Skinner S, et al. Factors influencing the development of antibiotic associated diarrhea in ED patients discharged home: risk of administering IV antibiotics. Am J Emerg Med. 2014;32:(10)1195-9. PMID: 25149599

This is a prospective cohort study of 247 patients, all of whom were being treated with outpatient oral antibiotics. They compared those who received an IV dose in the ED to those who did not. 25.7% of the IV group developed antibiotic associated diarrhea versus 12.3% in the no IV group (a number needed to harm of 7.5).

Bottom line: Unnecessary IV antibiotics harm our patients.


The best drugs are probably those they keep away from us

Calver L, Page CB, Downes MA, et al. The Safety and Effectiveness of Droperidol for Sedation of Acute Behavioral Disturbance in the Emergency Department. Ann Emerg Med. 2015. PMID: 25890395

This is a prospective observational study of 1009 patients in Australia, all of whom received 10mg of droperidol for sedation of acute behavioral disturbances, and second dose at 15 min as needed. Out of those 1009 patients, 13 developed a long QT, and 7 of those had other contributing causes such as methdone or amiodarone. There were no incidences of tosades de pointes.

Bottom line: The black box warning against droperidol is likely without scientific merit. I would use it if it were available to me. Given how useful this medication is, it might be worth fighting for.


Let’s do two on poo

Gerding DN, Meyer T, Lee C, et al. Administration of spores of nontoxigenic Clostridium difficile strain M3 for prevention of recurrent C. difficile infection: a randomized clinical trial. JAMA. 2015;313:(17)1719-27. PMID: 25942722

We are all colonized with C.diff., so we should be experts in getting rid of it. This is a new one to me. They took patients who completed their treatment for C.diff. and infected them C.diff. Only, this strain of C.diff does not form toxins. This reduced recurrence of clinical infection from 30% to 11%.

Bottom line: You can treat Clostridium difficile with Clostridium difficile. Maybe we should infect ourselves prophylactically?

Drekonja D, Reich J, Gezahegn S, et al. Fecal Microbiota Transplantation for Clostridium difficile Infection: A Systematic Review. Ann Intern Med. 2015;162:(9)630-8. PMID: 25938992

A systematic review, but there are only 2 RCTs to include. In one RCT, fecal trasplant led to 81% of patients having symptom resolution, versus only 31% in the vancomycin group. In another, they demonstrated no difference between NG and rectal routes for the transplant, with about 70% resolution of symptoms. (I’d choose the rectal route, thanks.)

Bottom line: Still really not enough science to warrant a bottom line, but if C.Diff is turning your life to sh*t, consider someone else’s sh*t: it might make you feel better.


Apparently science is useless for xanthrochromia.

Chu K, Hann A, Greenslade J, Williams J, Brown A. Spectrophotometry or visual inspection to most reliably detect xanthochromia in subarachnoid hemorrhage: systematic review. Ann Emerg Med. 2014;64:(3)256-264.e5. PMID: 24635988

This is a systematic review of 10 studies comparing visual inspection to spectrophotometry for detection of xanthrochromia. Visual inspection: sensitivity 83.3% and specificity 95.7%. Spectrophotometry: sensitivity 86.5% and 85.8%. (The gold standard varied from angiography to clinical follow-up.)

Bottom line: There is no clear difference between the two, but neither seem great. Isn’t there some way for the lab to test for the chemical that makes the fluid yellow?


1 + 1 + 1 = 3?

Angus DC, Barnato AE, Bell D, et al. A systematic review and meta-analysis of early goal-directed therapy for septic shock: the ARISE, ProCESS and ProMISe Investigators. Intensive Care Med. 2015. PMID: 25952825

Surprise. The meta analysis of three trials that said the same thing, says the same thing: EGDT is not superior to usual care in 2015. What is worth mentioning is that this is a very good meta-analysis because the investigators of all three trials went out of their way to ensure they were using the same definitions and outcomes before starting.

Bottom line: We can be very confident that we don’t need to be following the protocols of the original EGDT study.


Game changer (x2) for neonatal resuscitation?

Gruber E, Oberhammer R, Balkenhol K, et al. Basic life support trained nurses ventilate more efficiently with laryngeal mask supreme than with facemask or laryngeal tube suction-disposable–a prospective, randomized clinical trial. Resuscitation. 2014;85:(4)499-502. PMID: 24440666

A prospective, RCT comparing ventilation with facemask vs the LMA supreme (LMA-S) vs the laryngeal tube suction-disposable (LTS-D) device in neonatal resuscitation. A lot of the outcomes were of questionable relevance, but ventilation failed in 34% of patients with facemask, 22% with the LTS-D, and 2% with the LMA-S. Higher tidal volumes were delivered with both the LTS-D and the LMA-S than the facemask (470ml vs 240ml). All these resuscitations were run by nurses, so external validity may be questionable.

Trevisanuto et al. Supreme Laryngeal Mask Airway versus Face Mask during Neonatal Resuscitation: A Randomized Controlled Trial. The Journal of Pediatrics. 2015. PMID: 26003882

This is another prospective randomized trial (neither of these could be blinded) of LMA-S versus facemask in 142 neonatal resuscitations of infants greater than 34 weeks or 1500 grams. The LMA resulted in higher 5 minute APGAR scores, less intubations, and lower admissions to NICU.

Overall bottom line: These two prospective studies paint a picture of better ventilation as well as improved patient important outcomes, such as intubations and NICU admissions, when an LMA is used over standard facemask ventilation for neonatal resuscitation. This might cause some culture shock when we run upstairs, but I think this is worth instituting.


Another myth: The subglottic area is the narrowest area of the pediatric airway

Dalal PG, Murray D, Messner AH, Feng A, McAllister J, Molter D. Pediatric laryngeal dimensions: an age-based analysis. Anesth Analg. 2009;108:(5)1475-9. PMID: 19372324

These authors measured the cross sectional area of the airways of 153 children (6months to 13 years) using video bronchoscopy under general anesthesia, and they found that it is the glottis not the cricoid that is the narrowest portion of the airway.

Bottom line: Probably shouldn’t change your daily practice, still pick a tube small enough to pass the cords, but just remember that a lot of what we “know” and teach is wrong. Always keep an open mind in medicine.


Cheesy Joke of the Month

As the doctor completed an examination of the patient, he said, “I can’t find a cause for your complaint. Frankly, I think it’s due to drinking.”

“In that case,” said the patient, “I’ll come back when you’re sober”


FOAMed Resource of the Month

Its not actually up an running yet, but I am really excited about the idea, so its more something to keep an eye out for. If anyone has played around with Coursera or EdX, you know there is a lot of incredible high quality education available for free in just about any subject. These are called MOOCs (massive open online courses). Well, there will soon be an equivalent for emergency medicine education, created for ALiEM: http://www.aliem.com/sneak-peak-aliemu/