EMERGENCY PHYSICIAN USE OF ULTRASONOGRAPHY IN BLUNT ABDOMINAL-TRAUMA

Objective: To evaluate the diagnostic utility of abdominal diagnostic ultrasonography (DUS) performed by emergency physicians for intraperit oneal fluid caused by blunt abdominal trauma (BAT). Methods: The desig n was a prospective, blind, observational study. During a 15-month per iod, a convenience sample of patients presenting to the ED with BAT ne cessitating CT scan of the abdomen, diagnostic peritoneal lavage (DPL) , or laparotomy was studied. Scans were performed by an emergency medi cine (EM) attending, or a resident supervised by an attending, using a real-time sector ultrasound scanner with a 3.5-MHz probe. Training in DUS included a 1-hour didactic session and 1 hour of practice on huma n volunteers. Free intraperitoneal fluid was defined as an anechoic st ripe in the hepatorenal, bladder-rectal, or splenorenal space, and con stituted a positive DUS study. Free intraperitoneal fluid detected on abdominal CT scan, DPL, and/or laparotomy was the criterion standard. Results: Of 110 patients scanned, 13 were excluded secondary to techni cal difficulty or lack of diagnostic follow-up modalities. Of the rema ining 97 patients, there were 24 females and 73 males, ranging from ag es 2 to 78 years. DUS detected intraperitoneal fluid in 21 subjects, i ncluding 3 false positives. There were 6 false-negative DUS examinatio ns. DUS had a sensitivity of 75% (95% CI 53-90%), a specificity 96% of (95% CI 89-99%), and an accuracy of 91% (95% CI 83-96%). No false-pos itive or false-negative DUS study occurred after the first 67 cases. T he mean interval for a DUS scan was 4.9 +/- 2.9 minutes, ranging from 0.5 to 16 minutes, and the mean intervals were not different between t he positive and the negative studies. The accuracies of DUS were simil ar in the pediatric patients, 97% (95% CI 83-100%), and in the adults, 88% (95% CI 78-95%). The hepatorenal view provided the highest sensit ivity as well as the least number of uninterpretable scans of the 3 DU S views. Conclusion: Emergency physicians with minimal training can us e DUS with fair sensitivity and good specificity and accuracy to detec t free intraperitoneal fluid in both pediatric and adult BAT victims, The hepatorenal view provides the highest sensitivity for intraperiton eal fluid, although the 3-view series (with hepatorenal, bladder-recta l, and splenorenal spaces) can typically be performed within 5 minutes and may increase the specificity and accuracy.