blunt abdominal injuryThis month’s issue of JAMA addresses the question “Does this patient have a blunt intra-abdominal injury?” as part of the always-popular Rational Clinical Examination series.

The systematic review of the literature summarizes the accuracy of findings for your blunt trauma patient in diagnosing intra-abdominal injuries. Specifically, likelihood ratios (LR) are summarized. These LRs can be used to plot on the Bayes nomogram below. You draw a straight line connecting your pretest probability and the LR. This yields your posttest probability.

Bayes-1

The most predictive positive LR include: Abdominal rebound tenderness, a “seat belt sign”, ED hypotension, hematocrit < 30%, AST or ALT > 130, urine with > 25 RBCs, base deficit < -6 mEq/L, and a positive FAST ultrasound.

The trouble is that the absence of these findings aren’t as helpful in ruling-out injury, with negative LR’s very close to 1.0. The two exceptions are base deficit and FAST ultrasound with a negative LR of 0.12 and 0.26, respectively.


Adapted from 1
Go to the ALiEM Cards site for more resources.

I find it interesting that there are studies on hepatic transaminase levels. Anyone else getting these in their trauma patients? I traditionally don’t. Many of our patients have a history of hepatitis C and underlying alcoholic hepatitis. If suspicious for blunt abdominal trauma, we just get the CT.

1.
Nishijima D, Simel D, Wisner D, Holmes J. Does this adult patient have a blunt intra-abdominal injury? JAMA. 2012;307(14):1517-1527. [PubMed]
Michelle Lin, MD
ALiEM Founder and CEO
Professor and Digital Innovation Lab Director
Department of Emergency Medicine
University of California, San Francisco
Michelle Lin, MD

@M_Lin

Professor of Emerg Med at UCSF-Zuckerberg San Francisco General. Founder of ALiEM @aliemteam #PostitPearls https://t.co/7v7cgJqNEn
Michelle Lin, MD