“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
Month: October 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”
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