FOAM Eye-Catchers 3

The End of Therapeutic Hypothermia?  

GAME CHANGER!

HOT OF THE PRESS: this new article in NEJM, the Targeted Temperature Management (TTM) trial, that I came across initially courtesy of @CHsu1012 (and then from just about every FOAM resource on the planet due to the significance of these findings) found no benefit of cooling to 33 degrees v 36 degrees. That’s right – no benefit!

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FOAM Eye-Catchers 2

This week I caught up on my podcast listening and found some gems worth sharing.

 

The overly cautious patient who checks his blood pressure at home several times a day and the well intentioned pharmacist who directs a hypertensive patient to ED have been the bane of the Emergency Doctor for far too long. In your gut you know they do not need to be in your Emergency Department but till now you have been left in an evidence based vacuum as to how to safely approach these patients without excessively investigating and treating them.

Thankfully the American College of Emergency Physicians (ACEP) has just released a policy based on the available evidence on the topic that was reviewed recently by Scott Weingart on emcrit. There are some key recommendations that provides excellent and simple guidance for the clinician in this area:

Regarding the Investigation of Patients with Asymptomatic Hypertension

1. In ED patients with asymptomatic markedly elevated blood pressure, routine screening for acute target organ injury (eg, serum creatinine, urinalysis, ECG) is not required.

2. In select patient populations (eg, poor follow-up), screening for an elevated serum creatinine level may identify kidney injury that affects disposition (eg, hospital admission).

Regarding the Treatment of Patients with Asymptomatic Hypertension

1. In patients with asymptomatic markedly elevated blood pressure, routine ED medical intervention is not required.

2. In select patient populations (eg, poor follow-up), emergency physicians may treat markedly elevated blood pressure in the ED and/or initiate therapy for long-term control

3. Patients with asymptomatic markedly elevated blood pressure should be referred for outpatient follow-up.

So the bottom line is for most of your patients with asymptomatic hypertension, even markedly elevated, they can be discharged with a plan to see their GP to have followed up. While the guidelines leave open the option of emergency physicians initiating treatment, my experiences indicates that emergency physicians are not well versed in the correct choice of chronic oral antihypertensive agents for a given patient taking into account their co-morbidities. Therefore this is probably best left to those highly skilled in this regard – the general practitioner.

While all these recommendations are level C, given the known information about the dangers of urgent interventions to reduce BP causing strokes, these seem like a safe and common sense approach to an asymptomatic finding that is benign in the short term.

Bravo ACEP! The same unfortunately can’t be said about their thrombolysis for stroke guideline discussed below.

 

David Newman and Ashley Shreves released an excellent update reviewing recent key pieces of literature that are worthy of mention. I strongly recommend having a listen to the whole podcasts and reviewing the papers but here’s a brief summary of 3 papers:

1. Rapid Blood Pressure Lowering in Acute Intracerebral Haemorrhage

Published in NEJM by Anderson et al in June 2013.

This large trial (2839 patients) demonstrated that intensive BP lowering produced a small non significant (p=0.06) reduction in death or major disability of 3.6%. Hard to know what to make of this trial as it had several limitations including failing to show any benefit in the outcomes that were presumed to be the mechanisms of the therapeutic effect of BP reduction such as haematoma growth, neurological deterioration in the first 24hrs and recurrent intracerebral haemorrhage. Further given this was a non blinded trial where those receiving the intervention had more intensive other medical and nursing care, it is quite likely the non-significant benefit found was due to these other interventions and the lack of blinding.

Interesting study but not practice changing for mine. It suggests we need more research which is underway in ATACH-2 so watch this space.

 

2. Video Laryngoscopy v Direct Laryngscopy – and the winner is …

Effect of video laryngoscopy on trauma patient survival: a randomised controlled trial – published by Yeatts et al in Journal of Acute Care Surgery in August 2013

Large trial comparing the hyperangulated GlideScope Video Laryngoscope (GVL) against direct laryngoscopy (DL) in over 600 sick trauma patients. Notably this is the first RCT on the topic to my knowledge.

The winner is … Direct Laryngoscopy!

  • no difference in overall mortality or 1st pass success
  • median intubation duration was higher in the GVL group (56 v 40 seconds) (p=0.002)

  • a very concerning higher mortality due to GVL (30%) in the subgroup of severe head injury patients compared with DL (14%) (p=0.047) possibly due to higher median intubation duration (74 v  65 seconds, p<0.003) and resultant greater experience of sats less than 80% (50% v 24%, p=0.004). However this was a post-hoc exploratory analysis so would need further study to confirm if this is a real finding or just evidence of data mining.

A few massive limitations of this study:

  • about 1/3 of the patients were pulled out of the study by clinician discretion. These clinicians believed that Video was superior so mandated its use in those patients. So it is possible that GVL might have been better in these serious patients where the clinician mandated GVL use but we simply can’t know.
  • this study only evaluates the hyperangulated GlideScope which many would argue has already been surpassed by the standard mac blade shaped video laryngoscopes such as the C-MAC because typically the former device is great at getting a view but technically difficult at passing the tube. However I believe even the GlideScope has since come out with a mac blade shaped version as well.

  • So if you are using a Mac shaped Video Laryngoscope, the debate remains wide open. Intuitively one would think that given a device like the C-MAC is merely a standard laryngoscope with a video attached which gives you the option of direct and/or video laryngoscopy, it is hard to imagine that it can’t be advantageous. However we just don’t have the RCT data to back this intuition just yet.

    Disclosure: I receive no support or funding from any device maker.

     

    3. Transfusion Strategies for Acute Upper GI Bleeding

    Published by Villanueva et al in NEJM January 2013.

    921 patients comparing restrictive (transfuse if Hb <70) v liberal (transfuse if Hb<90) tranfusion strategies.

    Results:

    Liberal transfusion strategy produced a significantly lower survival (91% v 95%) at 45 days;  Number needed to kill = 25. Adverse events were higher in the liberal transfusion strategy with higher transfusion reactions, cardiac complications, acute kidney injury and bacterial infections. Unsurprisingly the Liberal strategy used much more units of blood (1638 v 671).

    Key exclusion group were people having active acute coronary syndrome as well as very mild and very severe bleeds.

    Given the strategy that is consumes more of the precious resource that is blood also produces a higher mortality and higher other adverse events, this study which builds on previous studies, should really be a practice changer right now (acknowledging the excluded groups).

     

    Fantastic discussion by David Newman recapping the old and the latest data on this issue explaining all the controversial complexities and specifically addresses the new  problematic ACEP guideline on the issue. It ends with a call to arms for clinicians to stand up and defend the scientific approach to medicine to protect our patients and the credibility of our profession. Even if you haven’t heard the original podcast on this topic from last year, you can still get the picture from this update. Inspiring stuff – highly recommend checking it out … and answering the call.

    For a great written summary of the evidence on lytics in stroke check out the nnt article.

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    FOAM Eye-Catchers

    This week we launch a new section of EMergucate called FOAM Eye-Catchers.

    The FOAM world (which of course includes EMergucate) is a diverse resource of up to date medical information available free of charge and Emergency Medicine is currently the epicentre of the FOAM world producing the vast majority of the content.

    When something in the FOAM world catches our eye, we will share that with our readers in this new section.

    In our first edition, this is what caught our eye:

    A great analysis of the evidence (or lack there of) for stress testing in low risk chest pain has been performed in a comprehensive smartem podcast previously. Now seemingly the largest prospective study (PMID 23689690) of this to date has been released and a great summary is on Dr Andy Neill’s blog.

    Essentially of the 4000 odd patients who underwent stress testing, only 0.7% had a lesion at angiogram that may benefit from coronary revascularisation under current AHA guidelines. For those true positives who received medical management instead, the benefit is harder to quantify (and is not done in the study) but based on the Framingham risk data, the number placed on medical therapy and the implied false positive rate, the overall absolute benefit for the cohort is likely substantially less than 1% over a 5 year period of medical therapy.

    Against this are the harms of the various stress tests (including the very low risks of test induced arrhythmia and radiation from stress myocardial perfusion imaging), the angiogram risks (eg stroke/MI) as well as the risks of the coronary revascularization interventions and medical management provided to the large numbers of false positives.

    Worth reading the whole article.

    During an informed consent process, it is becoming increasingly hard to sell the stress test to trop negative low risk ED patients.

    Dr Simon Carley published a good approach to recreational drug induced hyperthermia on the St Emlyn’s blog. Nice brief summary on the topic of drug induced hyperthermia generally with the focus on the recreational drug user who comes in hot.

    The HINTS exam is a 3 part exam (Head Impulse test, Nystagmus evaluation, Test of Skew, that has been developed by neurologist Dr David Newman-Toker (not to be confused with Dr David Newman of smartem) as an interesting tool for detecting posterior strokes amongst the mass of patients with Acute Vestibular Syndrome (AVS). Most patients with AVS have benign causes such as labrynthitis/vestibular neuritis but some have posterior strokes that we worry about.

    HINTS was promoted previously in an emcrit podcast with a video demonstrating the techniques.

    A more recent study of the HINTS exam has just been reviewed by EM Nerd and makes interesting reading.

    The HINTS exam is appealing but most of the data seems to be generated in a higher risk cohort where the test is performed by neurologists highly experienced in the techniques. It remains unclear how useful it will be when applied in a lower risk cohort by the average ED doc whose has just watched a how-to video. In particular the head impulse testing is difficult to do and the fear is that within this cohort a “normal” exam which is easy to find in unskilled hands (which supposedly suggests a central cause of AVS) may potentially send more benign patients down an imaging route then necessary. Still, it may be a useful weapon to add to the arsenal and in fact could be particularly beneficial in patients who are initially negative on imaging, as HINTS picked up some initial MRI negative patients as  posterior strokes, later confirmed on delayed MRI. This may be even more true when you only have access to a sub-optimal test such as CT initially.

    Important to note, this HINTS exam is not for your BPPV patients. It is designed for AVS only e.g. the patient with persistent vertigo that you think is labrynthitis/vestibular neruonitis but can’t be sure.