Research Roundup (March 2019)

In the first edition of the research roundup for 2019 we are going to cover pediatric head injury, oral antibiotics for complicated orthopedic infections, shaving eyebrows, bad science in the New England Journal of Medicine, a decision rule for opioid overdose, shark bites, heparin for ACS, cardiac monitoring in syncope, and how fast you have to move to outpace the Grim Reaper. Quite the eclectic mix. Make sure you check out the podcast version with my esteemed colleague Dr.  Casey Parker.

Clinical judgement: better than a kick in the head

Babl FE, Oakley E, Dalziel SR, et al. Accuracy of Clinician Practice Compared With Three Head Injury Decision Rules in Children: A Prospective Cohort Study. Annals of emergency medicine. 2018; 71(6):703-710. PMID: 29452747

This is a huge pediatric trial (19,000 patients) comparing 3 decision tools to clinical judgement. Although there has been a strong push to use decision tools, and we like the certainty that these rules seem to provide, few tools have proven better than clinical judgement. That is certainly the case here. The best tool was PECARN, with a 99% sensitivity and 52% specificity, but clinical judgement was a lot better (99% sensitivity but 93% specificity.) However, the physicians knew about the rules, so if you don’t know the components of the PECARN rule, you might not be as good. Maybe the most important take home from this study is that important injury is incredibly rare in pediatric head injury. The rate of neurosurgical intervention was only 0.1%, so CT scans for pediatric head injury should be few and far between.

Bottom line: You should know the components of the rules, but clinical judgement is probably better than clinical decision tools when deciding on imaging in pediatric head trauma.

The full write up can be found here.

I feel like a broken record: IV antibiotics aren’t magically stronger

Li HK, Rombach I, Zambellas R, et al. Oral versus Intravenous Antibiotics for Bone and Joint Infection. The New England journal of medicine. 2019; 380(5):425-436. PMID: 30699315

This is an RCT that included 1015 adult patients with complex orthopedic infections (septic arthritis, osteomyelitis, infected prosthesis, etc) traditionally thought to require 6 weeks of IV antibiotics. They randomized patients to oral or IV antibiotics, and oral therapy was non-inferior, but overall the oral group looks like they did better.

Bottom line: This is more evidence that there is nothing magically better about IV antibiotics.

The full write up can be found here.

You can shave people’s eyebrows – although I am not sure why you would want to

White T, Mellick LB. Debunking Medical Myths: The Eyebrow Shaving. Myth Emerg Med Open J. 2015; 1(2):31-33.

I am a sucker for myths. If you write a paper with myth in the title, you have a very good chance of getting included in the illustrious BroomeDocs Journal Club podcast, if that kind of thing interests you. In this paper, Larry Mellick (of YouTube fame) tackles the myth that shaving eyebrows will result in them either not growing back at all, or growing back abnormally.  They did a reasonable search, although only in one database, and I assume only in English. They couldn’t find a single paper that demonstrated abnormal growth after shaving. There was one study that looked at 5 individuals (I think healthy volunteers) and shaved one eyebrow. After 6 months, observers looking at a photograph couldn’t tell which eyebrow was shaved. I am not really sure the medical value of this information. I have never felt any need or desire to shave a patient’s eyebrows. But now you know that you can do it if you want to.

Bottom line: I have too much time on my hands.

The steady decline of the New England Journal of Medicine

Connolly SJ, Crowther M, Eikelboom JW, et al. Full Study Report of Andexanet Alfa for Bleeding Associated with Factor Xa Inhibitors. N Engl J Med. 2019 [free full text]

Despite its storied name, the New England Journal of Medicine might be the absolute worst medical journal in 2019. They seem to be more interested in advertising for pharmaceutical companies than discussing science. This useless paper on andexanet alfa highlights that point. It is an unblinded trial with no control group. They claim that patients given andexanet alfa had decreased factor Xa activity, and good hemostasis (although there was no correlation between those two). Without a control group, the trial tells us nothing, but the results look awful to me. They took a low risk population (any patient that was expected to die within 1 month was excluded), gave them an experimental drug, and 14% ended up dying. That’s not good.

Bottom line: We shouldn’t be using andexanet alfa until we see an RCT (which is coming).

The full write up can be found here.

Rapid discharge after naloxone?

Clemency BM, Eggleston W, Shaw EW, et al. Hospital Observation Upon Reversal (HOUR) With Naloxone: A Prospective Clinical Prediction Rule Validation Study. Academic emergency medicine. 2018; PMID: 30592101 [free full text]

How long do you observe a patient after an they receive naloxone? The practice varies widely around the world. This is a validation of the St. Paul’s early discharge rule. Unfortunately, the rule isn’t great, with a sensitivity of 85% and a specificity of 60%. Clinical judgement was as good as the rule. The components of the rule (vital signs, GCS, and ability to mobilize) are important consider, but probably should be combined with other factors like the route and type of opioid ingested, co-ingestants, co-morbidities, and the patient’s social situation.

Bottom Line: I won’t be using this rule in practice, but that doesn’t mean that all overdose patients need to be watched for 4-6 hours, as has been historically taught.

The full write up can be found here, and an SGEM episode is here

What do you call the mushy stuff between a great white shark’s teeth? Slow swimmers.

Tomberg RJ, Cachaper GA, Weingart GS. Shark Related Injuries: A Case Series of Emergency Department Patients. The American Journal of Emergency Medicine. 2018; 36(9):1645-1649.

We don’t have sharks in my part of Canada, so I read this paper on the plane to New Zealand. So far, it hasn’t helped me much clinically, but I think there were some fun details in here. (It’s a retrospective chart review from 10 emergency departments in Virginia, USA.) In a 9 year period, there were only 11 patients. They were white (90%) males (80%) with a mean age of 35. (That description is too close to me for comfort, and might explain why I haven’t tried to visit a local island that requires a swim across “shark alley”.) Half of the injuries occured when people were trying to take sharks off a fishing line. (This is the southern USA after all). Most were discharged directly home, and no one died. (That’s reassuring, so maybe I will risk shark alley after all). Infection is always a concern with salt water exposure. There was one infection in this cohort, although it was an admitted patient, and the cultures looked like a nosocomial infection, rather than a direct inoculation from the shark. The oral flora of sharks varies widely, but Vibrio was found in 70% of great white sharks. (Talk about adding insult to injury).

Bottom line: Sharks are probably mostly cool, unless you put your fingers in their mouth.

Heparin is harmful in NSTEMI and unstable angina

Chen JY, He PC, Liu YH, et al. Association of Parenteral Anticoagulation Therapy With Outcomes in Chinese Patients Undergoing Percutaneous Coronary Intervention for Non-ST-Segment Elevation Acute Coronary Syndrome. JAMA internal medicine. 2018; PMID: 30592483

This is probably the most important paper of the month. I have seen more than one patient die because of a misunderstanding of the importance of heparin in ACS. This is a retrospective chart review of 6800 NSTEMI and unstable angina patients, comparing patients who were given an anti-coagulant to those who were not. As expected, there was no change in mortality (we know heparin does not save lives). However, there also was no change in the rate of subsequent MI (0.3% vs 0.3%, p=0.82), which might surprise you if you haven’t read the heparin literature before. Despite providing no benefit, heparin was associated with an increase in major bleeding (2.5% vs 1%, p<0.001). Although this is only a retrospective chart review, it is consistent with all the literature on heparin, which is summarize here.

Bottom line: In patients with unstable angina and NSTEMI, heparin (in all forms) does not help, but does increase harms, and shouldn’t be used.

The full write up can be found here.

Achy Breaky Heart

Thiruganasambandamoorthy V, Rowe BH, Sivilotti MLA, et al. Duration of Electrocardiographic Monitoring of Emergency Department Patients with Syncope. Circulation. 2019; [pubmed]

I don’t use the Canadian Syncope Risk Score in my practice, and have never formally reviewed the paper, so it might not make sense to look at a follow up paper yet, but there has never been much order to these papers. (Blame Casey, he chose this article.) This is a pre-planned secondary analysis of the prospective database used to develop the Canadian Syncope Risk Score, with a focus on how long patients should be monitored in the emergency department. The primary outcome was a composite of serious outcomes, all of which are reasonable, but they are very different and illustrate how complex the syncope workup is. (We aren’t just looking for arrhythmias. GI bleeds, pulmonary hypertension, aortic stenosis, PE, AAA, dissection, ectopic pregnancy, and many other diagnoses are on our radar.) This paper focuses specifically on the arrythmias. They included 5719 syncope patients. 417 (7.5%) had a serious outcome in 30 days, 207 (3.7%) of which were arrhythmia related, although only 47 (0.9%) were serious arrhythmias or sudden death. They break these patients down according to their Canadian Syncope Risk Score. In the low risk group, there were 15 arrhythmias, 6 of which were caught with 2 hours of ED monitoring. In the medium risk group there were 92 arrhythmias, 45 of which were caught with 6 hours of ED monitoring. In the high risk group, there were 100 arrhythmias, 47 of which were caught with 6 hours of ED monitoring. In the medium and high risk groups, there were important arrhythmias all the way out to 30 days, so we clearly won’t catch them all, even with ED monitoring. It isn’t immediately clear what to do with this information. We will catch about ½ of arrhythmias with a short period of ED monitoring, but is half enough? On the other hand, most of these arrhythmias were not dangerous, and probably would have been caught simply by patient symptoms, so monitoring may not be all that important. No matter what we do, a small number of these patients (less than 1%) have truly bad outcomes (ventricular arrhythmias or death) in the 30 days after their ED visit.

Bottom line: 2-6 hours of monitoring in the ED will probably catch about half of arrhythmias in syncope patients.

Out pacing Death

Stanaway FF, Gnjidic D, Blyth FM, et al. How fast does the Grim Reaper walk? Receiver operating characteristics curve analysis in healthy men aged 70 and over. BMJ (Clinical research ed.). 2011; 343:d7679. PMID: 22174324 [free full text]

This is a great paper if you are trying to live forever. It gives you a benchmark to try to outrun the Grim Reaper. This is a secondary analysis of a large cohort of men over 70 years old in Sydney, Australia. They compared the time it took men to walk 6 meters at baseline to their mortality in the following 2-5 years. Their final sample included 1705 men, of whom 266 died. The mean walking speed was 0.88 meters/second. Men with a walking speed above 0.82 m/s were less likely to die than those who walked slower (LR 1.23; 95% CI 1.10-1.37). For every decrease by 1m/s in walking speed, there was a hazard ratio of 2.77 for death. No men who had a baseline walking speed over 1.36 m/s died, and therefore they conclude that Death must move slower than that.

Cheesy Physics Joke of the Month

Heisenberg is pulled over over by the police.

Cop: “You know, I caught you going 85.”

Heisenberg: “Great, now I’m lost!”