Category: Quality

Angiography After Cardiac Arrest

This is the worst sort of paper – nuggets of truth mired in systematic flaws.  There’s certainly no ill intent by the authors to mislead, it’s simply the nature of this sort of retrospective review.

The PROCAT consortium has been publishing studies of their post-arrest protocols for several years.  They’re huge proponents of early coronary angiography following resuscitation for out-of-hospital arrest – and this is another in a string of articles demonstrating that patients going to coronary angiography after out-of-hospital arrest have improved outcomes.  Of the 1274 patients in their cohort, 745 received early coronary angiography, 447 identified a culprit lesion, and 347 underwent PCI.  The survival rate was 46% in patients undergoing PCI.

However, this number is conflated by other confounding variables known to be associated with good outcomes following cardiac arrest – coronary lesions are likely to be associated with VT/VF, which were also associated with good outcomes.  Additionally, significantly more survivors received therapeutic hypothermia than non-survivors, illustrating the massive problem with viewing this sort of report with anything other than reasoned curiosity: rampant selection bias.  Patients survived because they were selected for interventions based on individualized prognostic features, treatments were not applied evenly across the population.

There is absolutely a subset of OHCA that benefits from early coronary angiography – but this benefit should not be generalized to the inappropriate allocation of resources associated with taking all OHCA to the cath lab after resuscitation.

“Benefit of an early and systematic imaging procedure after cardiac arrest: Insights

from the PROCAT (Parisian Region Out of Hospital Cardiac Arrest) registry”
www.ncbi.nlm.nih.gov/pubmed/22922264

Viral Testing in Children With Fever

This study attempts to address the question we’ve been asking ourselves since the dawn of antibiotics – does this child with a fever have a viral infection, or a bacterial infection?  Of course, in reality, we should be asking a more complicated question – does this child have a viral infection, or a bacterial infection for which the increased likelihood of positive outcome with antibiotics outweighs the harms of the antibiotics?  But, I digress.

One hypothesis that is bandied about in literature and practice is, if rapid viral testing were available in the Emergency Department, perhaps a positive viral test result would reduce the likelihood of antibiotic usage.  These folks from Washington University performed viral PCR for a host of common viruses on 75 children with fever without a source, 15 children with probable bacterial infections, and 115 afebrile children presenting for outpatient surgery.  The authors note the patients with bacterial infections were less likely to test positive for a virus – and suggest prospective trials might describe a strategy in which viral testing decreased antibiotic use.

In their cohort, 55% of children aged 2 to 12 months and 39% of those aged 13 to 24 months with no obvious source for fever received antibiotics.  This is irresponsible lunacy.  However, a much faster, cheaper way to decrease antibiotic use is:  to simply return from the abyss of antibiotic overuse to a land of rational practice.  

After all, 40% of the bacterial infections and 35% of the outpatient surgical patients tested positive for a virus – clearly indicating the presence of a virus has limited association with acute viral illness or absence of an acute bacterial infection.  More tests are not the answer – at least, certainly not this battery of PCR tests.

“Detection of Viruses in Young Children With Fever Without an Apparent Source”
http://www.ncbi.nlm.nih.gov/pubmed/23129086

Unsurprisingly, NHAMCS Data is Flawed

The National Hospital Ambulatory Medical Care Survey is a massive database of abstracted patient records, systematically generated to produce a representative sample of the nation’s Emergency Department visits.

It should come as no surprise that retrospectively abstracted data from the electronic medical record sometimes fails to accurately reflect patient care.  The important question, however, is “how often?”  This review of NHAMCS by one of the Annals editors looked at a measurement that ought to be pretty obvious – intubation.  If you can’t figure out whether a patient has been intubated via chart review, there’s some serious issues with your data sourcing.  However, in this review of NHAMCS, the author interprets up to one in four charts as being potentially inaccurate due to inconsistencies between documented intubation and the final disposition of the patient (e.g., non-ICU settings, home, observation status, etc.)

Now, there are some instances in which patients are intubated in the Emergency Department – yet not subsequently dispositioned to a critical care or morgue – but these “temporary” intubations certainly do not constitute 25% of intubations.  The author goes on to note that Annals publishes a NHAMCS study at least twice a year – relatively influential towards practice given the Impact Factor – and the flaws in this data should limit the relative weighting of its importance.

“Congruence of Disposition After Emergency Department Intubation in the National Hospital Ambulatory Medical Care Survey”

More Probably Unnecessary Head CTs/Admissions

I work at one of only two trauma centers in a city of four million potential patients, and I have firsthand experience with this issue.  The issue is to determine the best management strategy for patients with mild traumatic brain injury and bleeding.  We already know what to do with major bleeding – but patients with minor bleeding are a little more of a dilemma.  They almost universally do well, but we observe them and repeat tests on nearly all of them.

This is a retrospective review of 36 months of trauma admissions to a level one trauma center in New Jersey, trying to describe the natural progression of mild traumatic intracranial bleeding.  Historically, 1/3rd of these patients have bleeding that progresses, but only 1-3% will require neurosurgical intervention.  This review found 341 patients with mild injuries and bleeding, and noted that 69% of these patients had no interval change in head CT results when repeated at 24 hours.  Of the remaining patients, either no CT was performed (25 patients) because the injury was too insignificant or there was interval progression – including 11 patients who received neurosurgical intervention.  But, the point of the article is generally supposed to be shown in Figure 2 – estimating the number of ongoing hemorrhages at each time point in the first 24 hours.  Essentially, >80% of the bleeding ceases to expand within the first few hours from injury.

This is a useful jumping off point to perform the sort of work that isn’t featured in this article – characterizing the characteristics of patients and bleeding that progresses.  If patients with bleeding unlikely to progress can be safely discharged rather than being observed for interval CT, this is a useful reduction in ED length of stay, observation admissions, or CT use.

“The temporal course of intracranial haemorrhage progression: How long is observation necessary?”
www.ncbi.nlm.nih.gov/pubmed/22658418

The Emergency Medicine Literature is Tragic

This is a survey of the top twelve Emergency Medicine journals, as ranked by impact factor, providing a descriptive analysis of the features of the studies contained within.  The authors manually reviewed 330 articles and found a mere 8.8% were randomized studies.  Most (65.5%) were cross-sectional studies and 23.6% were cohort studies.  57.3% were prospective, 47.9% were from the U.S., and the minority of studies (31.2%) used informed consent or mentioned waivers of informed consent.


Compared with other fields, the surveyed EM literature was less likely to mention IRB approval, less likely to be prospective, less likely to be blinded and controlled, and enrolled fewer patients per study.


There are many barriers to research in the Emergency Deparment – particularly prospective, randomized, controlled research.  However, the establishment of an office for emergency services research at the National Institutes of Health may improve the ability of U.S. researchers to obtain grant funding.  

Of course, this will then only exacerbate the bias inherent in the already U.S.-centric published literature.


“Quality of publications in emergency medicine”

The Drivers of Inefficient Medicine

This is a lovely feature piece in the BMJ concisely detailing that surging occult demon consuming healthcare resources under the guise of “improved health” – overdiagnosis.  It’s really quite lovely to see the cultural changes coming in medicine, where increasing awareness of costs in the face of questionable benefit will reshape our profession in the years to come.

These authors, from Australia, describe twelve categories of “disease” that are expanding without obvious clinical benefit, as well as a brief overview of the sorts of practices that drive overdiagnosis.  It’s a bit of a lead-in to next year’s conference, Preventing Overdiagnosis, at Dartmouth University.

The entire article is worth reading, but I thought their table with the drivers of overdiagnosis was a nice summary:

  • Technological changes detecting ever smaller “abnormalities”
  • Commercial and professional vested interests
  • Conflicted panels producing expanded disease definitions and writing guidelines 
  • Legal incentives that punish underdiagnosis but not overdiagnosis
  • Health system incentives favouring more tests and treatments
  • Cultural beliefs that more is better; faith in early detection unmodified by its risks 
“Preventing overdiagnosis: how to stop harming the healthy”

Don’t Believe The Data

This NEJM study published a couple days ago addresses the effect of funding and methodological rigor on physicians’ confidence in the results.  It’s a prospective, mailed and online survey of board-certified Internal Medicine physicians, in which three studies of low, medium, and high rigor were presented with three different funding sources: none, NIH award, or industry funding.

Thankfully, physicians were less confident and less likely to prescribe the study drug for studies that were of low methodological quality and were funded by industry.  Or, so I think.  The study authors – and the accompanying editorial – take issue with the harshness with which physicians judge industry funded trials.  They feel that, if a study is of high methodological quality, the funding source should not be relevant, and we should “Believe the Data“.  Considering how easy it is to exert favorable effects on study outcomes otherwise invisible to ClincalTrials.gov and the “data”, I don’t think it is safe or responsible to be less skeptical of industry-funded trials.

Entertainingly, their study probably doesn’t even meet their definition of high rigor, considering the 50% response rate and small sample size….

“A Randomized Study of How Physicians Interpret Research Funding Disclosures”
www.ncbi.nlm.nih.gov/pubmed/22992075

Unnecessary Post-Reduction X-Rays?

Falling into the “well, duh” sort of category that cuts through the dogmatic haze, this article examines the ordering of post-reduction radiographs in the Emergency Department.

Specifically, this group of orthopedists from New York City looks at X-ray utilization and length-of-stay after consultation and management of minimally displaced, minimally angulated extremity fractures.  They note that, of 342 fractures meeting study criteria, 204 of them subsequently received post-splinting radiography.  They note that none of the patients receiving post-reduction radiography had any change in alignment or change in splint application, and this practice resulted in significantly longer ED length-of-stay.

This leads them to their conclusion that minimally displaced, minimally angulated extremity fractures that do not receive manipulation when splinting should not be re-imaged after splint application.  And, this seems like a fairly reasonable conclusion.  It’s retrospective, the outcomes are surrogates for patient oriented-outcomes, etc., and it would be reasonable to re-evaluate this conclusion in a prospective trial –   but if your practice is already to not routinely re-image, this supports continuing your entirely reasonable clinical decision-making.

“Post-Splinting Radiographs of Minimally Displaced Fractures: Good Medicine or Medicolegal Protection?”
http://jbjs.org/article.aspx?articleid=1356145

Longer Resuscitation “Saves”

This article made the rounds a couple weeks ago in the news media, probably based on the conclusion from the abstract stating “efforts to systematically increase the duration of resuscitation could improve survival in this high-risk population.”


They base this statement off a retrospective review of prospectively gathered standardized data from in-hospital cardiac arrests.  Comparing 31,000 patients with ROSC following an initial episode of cardiac arrest with a cohort of 33,000 who did not have ROSC – the authors found that patients who arrested at hospitals with higher median resuscitation times were more likely to have ROSC.  Initial ROSC was tied to survival to discharge, where hospitals with the shortest median resuscitation time having a 14.5% adjusted survival compared to 16.2% at hospitals with the longest resuscitations.


Now, if you’re a glass half-full sort of person, “could improve survival” sounds like an endorsement.  However, when we’re conjuring up hypotheses and associations from retrospective data, it’s important to re-read every instance of “could” and “might” as “could not” and “might not”.  They also performed a horde of patient-related covariates, which gives some scope of the difficulty of weeding out a significant finding from the confounders.  The most glaring difference in their baseline characteristics was the 6% absolute difference in witnessed arrest – which if not accounted for properly could nearly explain the entirety of their outcomes difference.


It’s also to consider the unintended consequences of their statement.  What does it mean to continue resuscitation past the point it is judged clinically appropriate?  What sort of potentially well-meaning policies might this entail?  What are the harms to other patients in the facility if nursing and physician resources are increasingly tied up in (mostly) futile resuscitations?  How much additional healthcare costs will result from additional successful ROSC – most of whom are still not neurologically intact survivors?


“Duration of resuscitation efforts and survival after in-hospital cardiac arrest: an observational study“

www.thelancet.com/journals/lancet/article/PIIS0140…9/abstract