Free Fluid Accumulation following Blunt Abdominal Trauma: Potential for Expansion of the Fast Protocol

Abstract

ObjectiveTo determine sites of free intra‐peritoneal fluid collection following blunt abdominal trauma, with a view to refinement of the Focused Assessment by Sonography for Trauma (FAST) protocol.MethodsThis was a retrospective observational study of CT scans of subjects who had suffered blunt abdominal trauma and had free intra‐peritoneal fluid detected on CT scan within 24 hours. The depth from the skin and amount of fluid at 14 abdominal sites were determined.ResultsCT scans of 105 patients were examined: 68 (64.8%) were male, mean age 36.7±18.4 years, mean injury severity score 25.4±11.6. Fluid collected most commonly at three sites: right mid‐axillary line at the level of the xiphisternum (52 patients, 49.5%), lateral margin of the right rectus muscle at the level of the anterior superior iliac spine (49 patients, 46.7%) and right mid‐axillary line at the level of the umbilicus (40 patients, 38.1%). Mean depth of fluid at these sites were 3.6, 3.6 and 4.2 cm, respectively.ConclusionsFree fluid collects commonly in the area of the right iliac fossa following blunt abdominal trauma. The inclusion of this site in the FAST protocol may increase the ultrasonographic detection of free fluid in the acute trauma setting.