By Michael Zwank, MD, FACEP
Holmes JF, Kelley KM, Wootton-Gorges SL, et al. Effect of Abdominal Ultrasound on Clinical Care, Outcomes, and Resource Use Among Children With Blunt Torso Trauma A Randomized Clinical Trial. JAMA. 317(22) 2290-96.
We all know that there are plenty of situations in which a FAST exam can provide useful and even life-saving information. A group of investigators at the University of California Davis wanted to examine this ultrasound application in a previously unstudied group - stable pediatric blunt trauma patients.
This was a randomized trial conducted at a single large pediatric trauma center. 925 hemodynamically stable pediatric patients with blunt torso trauma were randomized to either standard care or to standard care with FAST exam. The outcomes that were measured were rate of abdominal CT scans, missed intra-abdominal injuries, ED length of stay and hospital charges. All physicians who performed the FAST exams had met ACEP ultrasound guidelines and were credentialed.
In general, there were no differences in any of the outcomes… no fewer CT scans, no difference in missed injuries, no shorter length of stay, no decreased hospital charges. There was one missed intra-abdominal injury in the FAST group - a grade I liver laceration that was diagnosed two days after patient arrival (he was observed and did well). Of the 19 patients in the FAST cohort with intra-abdominal injuries on CT, the FAST exam was read as negative in 10 patients.
This was a well-done study. It included a lot of physicians and a lot of patients with diverse mechanisms of injury. The authors did survey the physicians and frequently their suspicion of intra-abdominal injury decreased after FAST but this did not translate into fewer CT scans. My only real critique of the study was that it was a single unique hospital (large pediatric trauma center) and this may limit its generalizability.
The study generally confirms what I teach our trainees. FAST has a very limited role in STABLE trauma patients. In stable trauma patients, its sensitivity (in this study and others) is poor even in very experienced hands. Don’t routinely perform FAST in stable trauma patients and don’t let the FAST results affect your clinical decision making.