Monday, October 15, 2012

A Month's Supply of Ketamine

This is a highly entertaining, short, qualitative survey of ketamine use in April 2011 at U.C. Davis.  Ketamine is quite popular outside the United States – but hasn't reached widespread, routine use here.

Specifically, this study looks at "low-dose ketamine" a supplementary analgesia in the Emergency Department.  Usually defined in the range of 0.1mg/kg to 0.3mg/kg, the authors use 0.2mg/kg.  Ketamine was generally efficacious, and adverse events were mild – highly limited by the size of their cohort, a mere 24 patients.  But the entertaining bit are the qualitative patient comments, including:

“I was in a science fiction movie.” 
“I was on TV.”
“I was a hippie.”
“It was pure euphoria.”
“I was scared.”
“I was hot.”

“It made me sleepy.”
“I was itchy.”

 ...and many others.

"Low-dose ketamine analgesia: patient and physician experience in the ED"

Friday, October 12, 2012

When Cardiologists Risk-Stratify Heart Failure

This is the "MARKED" score, a multi-marker prognostic risk score derived from emergency department patients presenting with acute dyspnea.  The authors state they've presented a "simple, straightforward" score that "may help the treating physician at the ED to decide on urge of intervention, admission, and timing of re-evaluation."

Sounds perfect!  A valuable tool to determine which patients are at high-risk for short-term mortality, possibly to predict which patients may have unanticipated poor outcomes if discharged home?

Ah, sadly, no.

When these cardiologists risk-stratify heart failure, they're using 90-day mortality – an endpoint almost certainly irrelevant to acute evaluation of dyspnea.  The authors recognize the "single-center" aspect of their study as a limitation – but, considering this comes from a dedicated "cardiology ED" in Holland, the external validity is extraordinarily limited.  The authors also do not offer any practical suggestion regarding how this score might be used in practice – or how decision-making using this score effectively changes outcomes compared with usual care.

Finally, this "simple" score features the commonly used laboratory tests such as NT-proBNP, high-sensitivty cardiac troponin T, Cystatin-C, high-sensitivity C-reactive protein, and Galectin-3.  It should be no surprise a few authors receive compensation from Roche Diagnostics and ACS Biomarker B.V.

"Multimarker Strategy for Short-Term Risk Assessment in Patients With Dyspnea in the Emergency Department"

Wednesday, October 10, 2012

tPA of The Future

"The potential benefits associated with this approach are faster reperfusion, lower risk of hemorrhage, and earlier initiation of fibrinolytic therapy, possibly by first responders."  

Sounds lovely, yes?  This is the pie-in-the-sky version of tPA, complete with flying cars and hoverbuses.  It's a "Clinical Implications of Basic Research" article from NEJM covering a Science article about shear-activated nanoparticles.

Essentially, in a mouse model of acute arterial thrombosis and pulmonary embolism, researchers bound tPA to aggregated nanoparticles.  In normal vasculature, these aggregates remain unaffected.  However, in regions of turbulence and shear associated with stenosis, the aggregates break apart, exposing the biochemically active tPA in greater quantities.  The authors, taking cue from the current political season, promise potential 100-fold reductions in dosing of tPA associated with this serendipitously targeted approach rather than standard systemic therapy.

So, someday, instead of taking an aspirin and calling 911 – home thrombolytics?

"The Shear Stress of Busting Blood Clots"

Monday, October 8, 2012

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"

Saturday, October 6, 2012

EMLitofNote on EM:RAP

With Rob Ormon[sic] of ERcast, discussing how (hopefully) coronary CT angiograms don't become as popular as July's discussants propose.

Sorry, I don't have my own readily distributable copy of the clip – but I do have an article coming in a few weeks in EMJ BMJ summarizing my views.

"CT Angio Again!"

Friday, October 5, 2012

Death By Horticulture

This case report, by the surgeons across the street at Baylor, describes a novel cause for bowel obstruction in children.  Apparently, in the course of plant cultivation, it is useful to have water-retaining gel spheres.  Advertised to retain water and grow to 400 times their original size, a child swallowed a "Water Balz" and developed a small bowel obstruction requiring laparoscopy and enterotomy.

More interestingly, the surgeons obtained five of these balls and evaluated their growth pattern.  The balls began life at ~0.95cm in diameter and, after 96 hours, reached a diameter of ~5.5cm, most of the growth in the first 12 hours.  Based on this, the surgeons estimate any swallowed balls would likely easily pass through the pylorus before resulting in complete bowel obstruction.

The claim of growth to 400 times size, however, is unfounded.  The balls they studied only grew to 200 times original size.

"Water-Absorbing Balls: A “Growing” Problem"

Wednesday, October 3, 2012

Trauma, the Hard Way

Anyone who has been to a surgery morbidity and mortality conference understands the cultural bias behind the desire to "pan-scan" all trauma patients.  If an injury is missed, and the body part wasn't scanned, someone is going to need to stand up and look foolish.

However, this article describes a trauma center in Boston that made a concerted effort to reduce CT scanning.  They came up with fifteen evidence-based guidelines for various scans and made a consensus to use these decision instruments to assist in their assessment for need for CT.  And, as you might expect, they identified significant reductions in CT scanning during their study period – 37% total reduction in number of CT scans.  If 37% doesn't sound like a big enough number, perhaps the $1.1M absolute difference in brain, chest, and abdomen/pelvis scan costs is enough to get your attention.

However, they have rather some weaknesses.  They state there were "no missed injuries", which is unusual because every study of CT in trauma patients fails to achieve 100% sensitivity – even in patients with liberal use of CT.  Then, they do have twice as many "complications" in their evidence-based scan group, as well as three times as many 30-day readmissions.  I'm not sure each complication follows from the scanning strategy, but it is an oddly significant difference.

Interestingly, they excluded patients who did not survive 24 hours.  Perhaps it complicated their abstraction process, but it is of slightly greater clinical interest to evaluate for potential missed injuries that resulted in immediate demise, rather than the misses that resulted in slightly longer-term morbidity.

"Evidence-based guidelines are equivalent to a liberal computed tomography scan protocol for initial patient evaluation but are associated with decreased computed tomography scan use, cost, and radiation exposure"

Monday, October 1, 2012

Pediatric Intubation – Not Always Successful

This is an observational study of pediatric medical resuscitation, published in Annals of Emergency Medicine, using video to evaluate the frequency of various adverse events during pediatric intubation.

As expected in a teaching institution, there is a fair bit of variability in initial success rates – ranging from 35% first-pass success for pediatrics residents up to 89% for PEM or anesthesia attendings.  Overall 52% had success on the first attempt.  Unfortunately, 61% experienced at least one adverse event during intubation.  These were typically not clinically important with regard to patient-oriented outcomes.

However,  what is more entertainingly concerning is how few of the complications make it into the medical record.  The written documentation overestimates first-attempt success, underestimates desaturation during the procedure, and even completely omits any mention of one of the two episodes of CPR required during resuscitation.

My guess is that Cincinnati Children's may have had a documentation quality review after this data were collected.

"Rapid Sequence Intubation for Pediatric Emergency Patients: Higher Frequency of Failed Attempts and Adverse Effects Found by Video Review"

Friday, September 28, 2012

"Say Anything", Regardless of the Data

As we've learned from prior publications, the conclusions section of the abstract is the ideal location to "spin" your article to generate news releases.  This article, from JAMA Neurology, compares thrombolysis to endovascular intervention for acute carotid artery occlusions and states "Intravenous thrombolysis should be administered as first-line treatment in patients with early cervical ICA occlusion."

That's a pretty strong statement, without qualifiers.  And, it means it received press coverage from MedPage Today, the ACEP News network, etc.

And, they base that statement on retrospective review of a cohort of 21 patients, 13 of whom received thrombolysis and 8 of whom received endovascular intervention.  The tPA patients did better, done and done, OR for early neurologic recovery 77 (95% CI 3 to 500).  But, then, Table 2 is a mini-systematic review of prior studies – and it turns out the rate of neurologic recovery is more like 40-50% with endovascular treatment, not the 1 in 8 they found in their retrospective cohort.  Indeed, the authors go on to state in the article "These findings are in contrast to the results of previous studies", and have an entirely reasonable, non-conclusive discussion of their findings in context of the other daa.

But, if you want news coverage, say something "interesting" in your abstract.

"Stroke From Acute Cervical Internal Carotid Artery Occlusion"

Wednesday, September 26, 2012

Acetaminophen and Asthma

If this article strikes your fancy – then you'll never look at acetaminophen the same way again.

Published in Pediatrics, this is a bit of a commentary summarizing epidemiological data in both children and adults related to the association between acetaminophen (paracetamol) use and asthma.  Specifically, that there is one, based on the studies he reviews, including:
• A prospective childhood asthma study of 520,000 subjects suggesting a dose-response effect between acetaminophen and asthma in children, up to an increased OR for wheezing of 3.25 for children taking acetaminophen at least once a month.
• A meta-analysis of six pediatric studies with a pooled increased OR for wheezing of 1.95 related to acetaminophen use.
• A meta-analysis of six adult studies with up to an increased OR for asthma of 2.87 for adults taking acetaminophen weekly.

...and several others.  The author does not suggest any specific mechanism through which acetaminophen increases airway reactivity, but he has changed his practice to reduce acetaminophen usage to the minimum.  I can't say I disagree with his hypothesis, and there does appear to be a preponderance of mounting evidence, although I wouldn't say this is an area where I am intimately familiar with the literature.

"The Association of Acetaminophen and Asthma Prevalence and Severity"

Monday, September 24, 2012

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 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"

Friday, September 21, 2012

The EHR – A Tool For Blocking Admissions

This is a mildly entertaining ethnographic study of how ED physicians, IM physicians, and surgeons used the Electronic Health Record (EHR) in the context of patient care in a tertiary medical center.

Essentially, the authors observed and interviewed residents and attendings in their use of the EHR, and identified its use in a function termed "chart biopsy" during the admission handoff process.  Inpatient teams were observed using the EHR to get a quick overview of the patient prior to the handoff, to provide the foundation for the history & physical, and – most entertainingly – to use as a weapon in negotiation and "blocking" potential admissions with ED physicians.  Other amusing anecdotes include the authors' characterization of inpatient physicians feeling "less 'at the mercy' of ED physicians" after doing a pre-handoff chart biopsy, or feeling as though they could guard against the "disorganized ramblings" off the handoff process.

Overall, the authors correctly identify EHRs as increasingly prevalent supplements to traditional information gathering techniques, and make a reasonable proposal for evolution in EHRs to aid the "chart biopsy" process.

"Chart biopsy: an emerging medical practice enabled by electronic health records and its impacts on emergency department-inpatient admission handoffs."

Wednesday, September 19, 2012

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?"

Monday, September 17, 2012

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"