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”
www.ncbi.nlm.nih.gov/pubmed/23041484

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”
www.ncbi.nlm.nih.gov/pubmed/23021334

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”
www.ncbi.nlm.nih.gov/pubmed/23034026

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”

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!”
http://www.emrap.org/episode/2012/october/ctangioagain?link=episode-segment

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”

www.ncbi.nlm.nih.gov/pubmed/22987870

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”
www.ncbi.nlm.nih.gov/pubmed/22929486

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”
www.ncbi.nlm.nih.gov/pubmed/22424653

“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”
http://www.ncbi.nlm.nih.gov/pubmed/23007611

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”
www.ncbi.nlm.nih.gov/pubmed/22065272