Saturday, April 21, 2012

"Malodorous" Urine Isn't Necessarily a UTI

Which is to say, when a parent brings in a child with a fever and the urine "smells bad", plenty of those kids have normal urine cultures and plenty of children with Febreeze for urine have a urinary tract infection, regardless.

This is a prospective cohort study enrolling children receiving a urine culture as part of an evaluation for fever without a source in the Emergency Department - and then they went back and data mined for associations between the group diagnosed with UTI and not.  The overall incidence of UTI was 15%.  The overall incidence of UTI in those with "malodorous" urine was 24%.  It was the most significant contributing factor they found, but it's still not sensitive or specific enough to use in isolation to change management.

Other interesting tidbits:  no circumcised male had a UTI, known high-grade vesicoureteral reflux predicted UTI.

"Association of Malodorous Urine With Urinary Tract Infection in Children Aged 1 to 36 Months"

Thursday, April 19, 2012

Uninterrupted CPR is Better Than Interrupted

This is from King County, which has been publishing retrospective pre- and post- intervention outcomes related to out-of-hospital cardiac arrest for several years now.  This article focuses on the AHA guidelines for PEA and asystole, and the changes that were made in 2004 and 2005.  Those changes, if you recall, involve fewer pauses for pulse and rhythm checks and decreasing the number of ventilations.

Good news!  You were 1.5 times more likely to survive neurologically intact to hospital discharge after the introduction of the new guidelines.  Bad news: good neurological outcome was still only 5.1%, up from 3.4%.  So, yes, this is another piece of evidence supporting the "uninterrupted, high-quality CPR" concept, but perhaps the other important question that need be asked at the same time is:  how can we reduce the unnecessary resource expenditure associated with attempted resuscitation for the 95% that doesn't benefit?

"Impact of Changes in Resuscitation Practice on Survival and Neurological Outcome After Out-of-Hospital Cardiac Arrest Resulting From Nonshockable Arrhythmias"

Tuesday, April 17, 2012

Post-Arrest Troponin Measurements Predict Little

Taking post-arrest patients to cardiac catheterization improves outcomes - as long as they have a cardiac occlusion as the underlying etiology of their arrest.  Otherwise, you're simply delaying the diagnosis and treatment of alternative causes, as well as post-arrest ICU-level care.  Therefore, if there is some clinical feature that can be identified on initial Emergency Department evaluation that predicts a coronary occlusion, that would be of great value.

So, this is a retrospective analysis of a prospective registry of out-of-hospital arrests from Paris, where much of the post-arrest catheterization work has been done.  And, unfortunately, there isn't any useful association - 92% of their patients had elevated troponin on initial evaluation.  There was a nonsignificant trend towards higher troponin levels in patients with coronary occlusion, but even at their "optimum" cut-off of 4.66ng/mL, the sensitivity and specificity were nearly coin-flip at 66% each.  A troponin of 31ng/mL was required for 95% specificity.

ST-segment elevation, incidentally, was more predictive of a coronary occlusion - OR 10.19 (CI 5.39 to 19.26).

"Can early cardiac troponin I measurement help to predict recent coronary occlusion in out-of-hospital cardiac arrest survivors?"

Sunday, April 15, 2012

The Dexamethasone Dose for Croup is 0.15mg/kg

Unfortunately, this is still probably not the trial that convinces everyone.  In fact, it's been over 15 years since the original single-center trials/reports showing that 0.15mg/kg of dexamethasone was every bit as effective as 0.6mg/kg of dexamethasone.  This makes intuitive sense, considering the steroid equivalencies, and the doses used in studies that have established prednisolone as an adequate treatment for croup, as well.

Regardless, this is a very small - 30-odd patients - with mild croup, randomized to dexamethasone at 0.15mg/kg vs. placebo.  The point of this study was not to test the efficacy of dexamethasone, but rather to show that, despite it's long half-life, it had immediate effects.  And, I think it's fair to say this study demonstrates those significant effects in reduction in croup score, gaining statistical significance by 30 minutes.

I don't know where the attachment came from in terms of the 0.6mg/kg dose of dexamethasone, but it's just preposterously high.

"How fast does oral dexamethasone work in mild to moderately severe croup? A randomized double-blinded clinical trial."