Articles of the Month (March 2016)

My monthly summaries of the medical literature

Every month I select the best medical articles I have read and provide brief summaries and critical appraisals. Here are this month’s articles:

The paper you are most likely to hear about this month: antibiotics and abscesses

Talan DA, Mower WR, Krishnadasan A. Trimethoprim-Sulfamethoxazole versus Placebo for Uncomplicated Skin Abscess. The New England journal of medicine. 374(9):823-32. 2016. PMID: 26962903

Until now, the data on abscess management has been pretty clear: all you need is cold hard steel. No packing, and definitely no antibiotics. Has management just become much more confusing? This is a large, multi-center RCT comparing trimethoprim-sulfamethoxazole (320mg/1600mg MID for 1 week) to placebo in 1247 adult patients with acute abscess greater than 2cm in diameter. For the primary outcome of clinical cure at 7 days, the antibiotics group was better (80.5% versus 73.6%; absolute difference 6.9% 95%CI 2.1-11.7%; NNT = 14). There were also decreases in several secondary outcomes, such as new skin infections at other sites. However, there was an increase in GI side effects by about 7% (42.7% vs 36.1%). A cure rate of only 75% is really low and doesn’t represent the patients I see. This is probably because these are not simple abscess, with a median cellulitis area of 6.5×5.0cm, 20% of the cohort with a cellulitis area greater than 75cm2, and many patients “met other guideline criteria for antibiotics treatment”. (You can read some other opinions on REBEL EM, EM Nerd, and EM Literature of Note.)

Bottom line: This isn’t a game changing paper. It tells you to keep using antibiotics in the patients you are already using them in – complex abscesses with cellulitis – and doesn’t tell us a lot about the average abscess.


How ready are you for a mass casualty event?

Bhalla MC, Frey J, Rider C, Nord M, Hegerhorst M. Simple Triage Algorithm and Rapid Treatment and Sort, Assess, Lifesaving, Interventions, Treatment, and Transportation mass casualty triage methods for sensitivity, specificity, and predictive values. The American journal of emergency medicine. 33(11):1687-91. 2015. PMID: 26349777

I found this paper fascinating. I won’t get into detail about the performance of the scores, because the data is retrospective, and there is too much information that these scores use that would not be well recorded. However, I think this is a great study to read. I had never been exposed to a mass casualty triage system before, nor do I think I have been adequately trained in this aspect of emergency medicine. The algorithms are interesting. It’s worth a read.

Bottom line: Are you for a mass casualty event? This article might help


How do you tell if a patient needs more pain medication? Ask them

Chang AK, Bijur PE, Holden L, Gallagher EJ. Efficacy of an Acute Pain Titration Protocol Driven by Patient Response to a Simple Query: Do You Want More Pain Medication? Annals of emergency medicine. 2015. PMID: 26074387

I am strongly biased to like this study, because I was always thaught this is the way that pain medicine should be given (by Jerry Hoffman, I think). This is a prospective cohort of 215 adult patients presenting to the ED for acute painful conditions that the attending physician thought required an opioid. All patients received hydromorphone 1mg IV, followed by up to 3 more 1mg IV doses every 30 minutes driven entirely by their response to the question “Do you want more pain medication?” There were delays in administration of medication, so the max was actually 4mg over 4 hours. 205 of the 207 patients (99% 95%CI 97-100%) achieved pain control on 1 or more occasions during the study; 97% were either satisfied or very satisfied with their pain treatment. About 20% of patients wanted more pain meds at each interval. What can we learn from this study? The design of the study allows us to conclude that this method will leave most people satisfied with their pain control, and that almost everyone will reach a point where they don’t want any more analgesia. However, with no comparison, we have no idea if this technique is any better or worse than other methods. Personally, I am interested in how this would compare to patient controlled analgesia – which would require a larger upfront investment, but I think would be more tolerable for nursing workloads.

Bottom line: Asking patients is a reasonable method to determine if they need more analgesia


2 is not be better than 1 when in comes to needles

Martin SP, Chu KH, Mahmoud I, Greenslade JH, Brown AF. Double-dorsal versus single-volar digital subcutaneous anaesthetic injection for finger injuries in the emergency department: A randomised controlled trial. Emergency medicine Australasia : EMA. 2016. PMID: 26991958

Injections in the palm always seemed painful to me, so I always stuck with the double dorsal injection technique. I don’t remember why I changed, but my success rate is much better with the single palmar injection, so I’ve never looked back. The study: 86 adult patients in an RCT comparing a double-dorsal to a single-palmar injection technique for digital nerve block. There was no difference in the pain of injection between the two techniques (almost 4/10). The techniques were equally successful (65% success with double-dorsal and 72% with single-palmar). Really, none of those numbers are great.

Bottom line: Stick with the bloc you are used to – and maybe add some bicarb to get the pain on injection down?


Dumb and dumberer

Maltese F, Adda M, Bablon A. Night shift decreases cognitive performance of ICU physicians. Intensive care medicine. 42(3):393-400. 2016. PMID: 26556616

This is a prospective, randomized, cross-over study of 51 ICU doctors (27 residents, 21 attendings) who were randomized to either work a night shift or rest at home (and then were crossed over to the opposite group). Between 10am and noon the next day they went through a series of psychological tests. Not surprisingly, working memory, information process speed, and perceptual reasoning were all worse after a night shift. Cognitive flexibility was not statistically different. The clear issue with the study is we have no idea how these psychological tests translate into patient care, or whether the measured differences are actually clinically important differences.

Bottom line: Night shifts are hard. It’s hard to make good decisions at 4am. (One of many reasons I like the idea of casino shifts).


How safe is that treatment really?

Saini P, Loke YK, Gamble C, Altman DG, Williamson PR, Kirkham JJ. Selective reporting bias of harm outcomes within studies: findings from a cohort of systematic reviews. BMJ (Clinical research ed.). 349:g6501. 2014. PMID: 25416499 [free full text]

These authors attempt to examine the accuracy of reporting of harms in clinical trials. They identified trials that had been included in systematic reviews, and then evaluated each trial for how they reported harms (ie, harms measured and reported, harms not measured, harms measured but only partially reported, harms not even mentioned…). When looking at all Cochrane reviews, they found that the studies only partially reported or didn’t report harms at all 76% of the time. In a group a systematic review designed specifically to look at adverse events, 47% of studies still did not report or only partially reported a single primary harm outcome. This tendency of the literature has been discussed before. We tend to minimize our discussion of harms, which obviously skews our conclusions when looking at the entirety of the literature.

Bottom line: For every medicine you use, remember that the harms are probably greater than those reported in clinical trials


Clinical correlation required

Mark DG, Sonne DC, Jun P. False negative interpretations of cranial computed tomography in aneurysmal subarachnoid hemorrhage. Academic emergency medicine : official journal of the Society for Academic Emergency Medicine. 2016. PMID: 26918885

This is a chart review that identified 452 patients diagnosed with subarachnoid hemorrhage, and looked at the subset of 18 patients (4%) who were diagnosed by lumbar puncture after a normal CT. The supposedly normal CTs were then reviewed by 2 speciality neuro-radiologists, and in 9 of the 18 (50%) the neuro-radiologists thought there was evidence of bleed on the scan initially reported as normal. The false negative rate was 71% (5 of 7) for the scans done within 6 hours of headache. Of course, re-reading studies without the time pressures of a normal shift, especially when LPs have already shown blood (although these radiologists were blinded) might be easier.

Bottom line: Radiology isn’t perfect. Not all radiologists are created equal. This might still be the fatal flaw in the famous Perry study


But doc, it hurts A LOT

Body R, Lewis PS, Carley S, Burrows G, Haves B, Cook G. Chest pain: if it hurts a lot, is heart attack more likely? European journal of emergency medicine : official journal of the European Society for Emergency Medicine. 23(2):89-94. 2016. PMID: 25340995

Does the pain score correlate with the chance of MI? This is a secondary analysis of a data set collected for a prospective cohort study that included emergency department patients with suspected cardiac chest pain. They looked at the pain scores of the patients with a final diagnosis of MI, as compared with those who ruled out. Although there was a statistical difference, with the average pain in the MI group being 8/10 (interquartile range 5-8) and the non-MI group being 7/10 (IQR 6-8) (p=0.03), those numbers obviously don’t help clinically. This is reinforced by their analysis that showed the area under the receiver operating curve was 0.58, so essentially a coin flip. The amount of pain might have influenced the original physicians in terms of who was included in the dataset, which would skew these numbers.

Bottom line: The intensity of pain does not seem to help diagnostically in ACS.


Not the worry, that blurry vision and headache should be gone in … 90 days?

Kriz PK, Stein C, Kent J. Physical Maturity and Concussion Symptom Duration among Adolescent Ice Hockey Players. The Journal of pediatrics. 2016. PMID: 26781190

How long do pediatric concussion symptoms last? This is a prospective cohort of 145 patients aged 13-18 years who were referred to a sports medicine clinic. The mean symptom duration was 45 days (though with wide confidence intervals of +/- 49 days). About half (48%) of patients had symptoms for more than 28 days, and 13% had symptoms beyond 90 days. So perhaps concussion symptoms last longer than we usually counsel, but I worry about a significant selection bias here, as we don’t refer most kids with concussion to sport medicine clinics, and this is only 145 children from 3 clinics over 2.5 years. It probably represents the worst case scenario.

Bottom line: Some children will have prolonged concussion symptoms. Counselling and follow up instructions should keep this in mind


I have to say, the heart is what won me over when it comes to POCUS

Martindale JL, Wakai A, Collins SP. Diagnosing Acute Heart Failure in the Emergency Department: A Systematic Review and Meta-analysis. Academic emergency medicine : official journal of the Society for Academic Emergency Medicine. 2015. PMID: 26910112

This is a systematic review looking the diagnosis of congestive heart failure in the emergency department. Probably because CHF actually encompasses a few different underlying pathologies, their major finding was that no factors were good enough to single handedly rule in or rule out CHF. Some likelihood ratios: Audible S3 +LR 4.0, CXR signs of edema +LR 4.8, B lines on bedside US +LR 7.4, no B-lines -LR 0.16, and reduced ejection fraction on bedside echo +LR 4.1. (Remember you want a positive likelihood ratio of 10 or more to rule in, and a negative likelihood ratio of 0.1 or less to rule out.)

Bottom line: Ultrasound may be our best tool for diagnosing CHF, but no findings can be used in isolation to rule in or rule out the disease.


There are now bottles of water labeled “gluten free”

Zanini B, Baschè R, Ferraresi A. Randomised clinical study: gluten challenge induces symptom recurrence in only a minority of patients who meet clinical criteria for non-coeliac gluten sensitivity. Alimentary pharmacology & therapeutics. 42(8):968-76. 2015. PMID: 26310131

I get asked a lot about gluten, as I am sure many people do, not just by emergency medicine patients, but also friends and families. In this study they took 35 patients who had tested negative for celiac disease but self-identified as being gluten intolerant and in a double blind, cross-over design they exposed the patients to either gluten free or normal flour. 12 (49%) of the patients thought the gluten-free flour contained gluten – what you might guess if the guess was pure chance. I think the evidence is pretty convincing that gluten is not the issue for most people without celiac disease. These patients definitely have symptoms, but there are almost certainly other etiologies than gluten. I worry that the focus on gluten pushed by some ‘experts’ is doing patients a disservice.

Bottom line: In people without celiac disease, symptoms are not consistently reproduced by gluten.


The case of the killer iPhone

Tri JL, Severson RP, Hyberger LK, Hayes DL. Use of cellular telephones in the hospital environment. Mayo Clinic proceedings. 82(3):282-5. 2007. PMID: 17352363

These authors brought 2 telephones into different patient rooms and made phone calls while observing various medical devices. In total they did 300 tests of 192 difference devices in 75 patient rooms, and they were unable to document a single case of the cellular telephone interfering with medical equipment.

Bottom line: The ban on cel phones may be based on a myth?

Continued…

Lawrentschuk N, Bolton DM. Mobile phone interference with medical equipment and its clinical relevance: a systematic review. The Medical journal of Australia. 181(3):145-9. 2004. PMID: 15287832 [free full text]

This is a systematic review looking at the question of mobile phone interference with medical equipment. They identified 8 studies that tested a total of 936 devices. (Studies ranged from 1994-2002, so technology may have changed since.) They found that interference did occur in as many as 6% of tests. However, essentially all of this interference occurred when the phone was within 1 meter of the device – so you probably have to be trying to cause interference, like they were in these studies, rather than just using phones normally. Also, the results of the interference were not recorded, so it’s difficult to know if any of it was clinically relevant. (Some brief interference on an ECG monitor is irrelevant, but I would care about a pacemaker that stopped pacing.)

Bottom line: This is a little more complex than the last paper indicated, but it appears phones are safe as long as they are more than a meter from medical equipment. (Although that might be hard in some of the cramped resuscitation rooms I have worked in.)


NSAIDs for 11/10 pain

Pathan SA, Mitra B, Straney LD. Delivering safe and effective analgesia for management of renal colic in the emergency department: a double-blind, multigroup, randomised controlled trial. Lancet (London, England). 2016. PMID: 26993881

This is a double blind RCT of 1644 adult patients with renal colic (1316 confirmed on CT) comparing morphine (0.1mg/kg IV) to diclofenac (75mg IM) to acetaminophen (1 gram IV). For a primary outcome of a 50% reduction in pain at 30 minutes, diclofenac was more effective than either morphine or acetaminophen, which weren’t different from each other (OR 1·35, 95% CI 1·05-1·73, p=0·0187). This means that 68% of the diclofenac group had a 50% reduction in pain, as compared to 61% with morphine and 66% with acetaminophen – not a huge absolute difference. One interesting number is that only 12% of the IM diclofenac group needed any rescue medication, so it might be possible to manage renal colic without ever starting an IV. Adverse events were statistically higher in the morphine group, but really quite low (1-3%) in all groups. Personally, I like a multimodal pain approach, and will probably continue to combine NSAIDS and opioids.

Bottom line: It might be true that NSAIDs are slightly more effective in renal colic


#FOAMed of the Month

This is a really short post on the Nurse Path, but I love it because it is a simple yet brilliant method for improving communication and patient safety. The key is that for medication checks, rather than reading out the dose and asking the person confirm ‘yes or no’, which could result in confirmation bias or error, you simply ask “what is this?” That forces the other person to slow down and actually read the medication out loud. I imagine this technique could also be used in another of other situations as well.


 

 

Cheesy Joke of the Month

Two orthopedic surgeons are on opposite sides of a lake.

One surgeon yells to the other, “How do you get to the other side?”

The other responds, “You are on the other side!”

Author: Justin Morgenstern

Community emerg doc, FOAM enthusiast, evidence 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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