An algorithm to reduce the incidence of false-negative FAST* examinations in patients at high risk for occult injury

Background: The Focused Assessment for the Sonographic Examination of the T rauma patient (FAST) sequentially surveys for the presence or absence of bl ood in dependent abdominal regions including the right upper quadrant, left upper quadrant, and the pelvis. But it does not readily identify intrapare nchymal or retroperitoneal injuries, and a CT scan of the abdomen may be ne eded to reduce the incidence of missed injuries. We hypothesized that selec t patients who are considered high risk for occult injuries should undergo a CT scan of the abdomen when the FAST is negative so that occult injuries can be detected. Study Design: An algorithm was prospectively tested for the evaluation of s elect injured patients over a 31/2-year period. Entrance criteria included adult patients with a blunt mechanism of trauma, a negative FAST examinatio n, and a spine fracture (with or without cord injury), or a pelvic fracture . Trauma team members performed the FAST on patients during the Advanced Tr auma Life Support secondary survey. Data recorded included the patient's me chanism and type of injury, the results of the FAST and CT scan examination s, operative or postmortem findings or both, and patient outcomes. Patients with spine injuries were grouped according to spine level and the presence or absence of neurologic deficit. The patients with pelvic fractures were grouped according to the Young and Resnick classification. Results: One hundred two of 1,490 patients (6.8%) who had FAST examinations were entered into this study. Thirty-two patients (30.5%) had spine injuri es, with only one false-negative ultrasound result. Seventy patients (68.6% ) had pelvic fractures with 13 false-negative ultrasound results: II ring ( 3 from motor vehicle crashes, 2 from pedestrians struck), 1 acetabular, and 1 isolated pelvic fracture. Nine patients underwent nonoperative managemen t for solid organ injuries, and 4 patients needed surgery. Conclusions: Based on these preliminary data, we conclude that patients wit h pelvic ring-type fractures should have CT scans of the abdomen because of the higher yield for occult injuries. (J Am Coll Surg 1999;189: 145-151. ( C) 1999 by the American College of Surgeons).