Clinical importance of intraperitoneal fluid in patients with blunt intra-abdominal injury

The purpose of this study was to determine the prevalence of intraperitoneal fluid (IF) in blunt trauma patients with intra-abdominal injuries, to determine the rate of exploratory laparotomy in patients with and without IF, and to identify the location of this IF. We retrospectively reviewed the records of 604 patients with intra-abdominal injuries after blunt trauma who were admitted to a level 1 trauma center over a 42-month period. Patients were considered to have intra-abdominal injuries if an injury to the spleen, liver, urinary tract, pancreas, adrenal glands, gallbladder, or gastrointestinal tract was identified on abdominal computed tomography (CT) or at exploratory laparotomy. Patients were considered to have IF if fluid was identified on abdominal CT or during exploratory laparotomy. In patients undergoing abdominal CT or abdominal ultrasound (US), the specific location of the IF was identified. Four hundred forty-three (73%, 95% confidence interval [CI] 69 - 77%) of the 604 patients with intra-abdominal injuries had IF. Patients with IF had an increased risk of laparotomy (344/443 [78%] v 44/161 [27%], odds ratio = 9.2, 95% CI 6.1-13.9). Of the 539 patients undergoing abdominal CT or abdominal US, IF was identified in 389 (72%) and was visualized in the following locations: 258 of 389 (66%) in Morison's pouch, 216 of 389 (56%) in the left upper quadrant, 187 of 389 (48%) in the pelvis, and 139 of 390 (36%) in paracolic gutters. Three patients with IF visualized solely in the paracolic gutters underwent laparotomy. The majority of patients with intra-abdominal injuries have IF, and these patients are more likely to undergo laparotomy. Morison's pouch is the most common location for IF to be detected with radiologic imaging. However, visualization of the paracolic gutters with abdominal US may detect IF in patients with intra-abdominal injuries that would otherwise not be detected by US.