Clinical predictors of injuries not identified by focused abdominal sonogram for trauma (FAST) examinations

This study's objective was to identify clinical characteristics of patients with a blunt traumatic injury that increased the risk of peritoneal or pericardial fluid collections and abdominal organ injuries not identified by a bedside focused abdominal sonogram for trauma (FAST) examination. This observational study used a retrospective chart review of a cohort of patients identified through a query of the University of Nebraska Medical Center's trauma registry, a tertiary referral center for portions of Nebraska, Iowa, and Missouri. Adult patients presenting to the Emergency Department (ED) for an evaluation of blunt traumatic injury from September 1996 to December 2002 were eligible if their ED course included admission to the trauma service after completion of a bedside FAST examination (US) and a confirmatory study (Conf) such as an abdominopelvic computed tomography scan or exploratory laparotomy within 12 h of completion of the ED FAST examination. The medical records of those patients with a US+/Conf+ or US-/Conf+ examination were reviewed. Clinical characteristics were recorded on a standard data collection form. Statistically significant predictors of a US-/Conf+ examination were found using a stepwise logistic regression procedure. A query of the trauma registry for the study period revealed 1453 adult individuals with blunt abdominal trauma, with 458 patients meeting the inclusion criteria. The clinical characteristics of the 79 US+/Conf+ examinations were compared to those of the 53 US-/Conf+ examinations. The presence of a radiographically proven pelvic fracture (odds ratio 3.459; 95% confidence interval of 1.308-9.157) and a radiographically or operatively proven renal injury (odds ratio 3.667; 95% confidence interval of 1.013-13.275) were found to be significant predictors. The presence of a pelvic fracture or renal injury in adult victims of blunt abdominal trauma increases the likelihood of a US-/Conf+ examination. Patients with a negative FAST examination and pelvic fracture may benefit from additional radiographic or operative evaluations for occult injuries.