ABSTRACT
Focused Assessment for the Sonographic Examination of the Trauma patient Since first described by Rozycki et al., the Focused Assessment for the Sonographic examination of the Trauma patient (FAST) has become the accepted primary modality for imaging most patients with possible truncal trauma.(10) In fact, the most recent version of the Advanced Trauma Life Support (ATLS) manual considers the FAST as an adjunct to the primary survey.(1) The study involves an ultrasound (US) examination of four areas including the pericardial sac, right upper quadrant, left upper quadrant and pelvis, and can be easily learned. The FAST is rapid, noninvasive, and can readily be performed at the bedside. It is easily reproducible and can be performed serially to evaluate for changes.(10, 11) Overall, reported sensitivities for the study range 81-98% for the detection of intra-abdominal injury.(10, 12-15) In hypotensive patients with blunt trauma to the abdomen, the FAST exam has a sensitivity of 100% and a specificity of 99.3%.(16)
McKenney et al. described a hemoperitoneum score following a retrospective analysis of 400 positive US examinations. To determine the score, the anterior to posterior depth of the largest collection of fluid is first measured to the nearest 10th of a centimeter. Then, a point is added for each additional area positive for fluid. For example, a patient with a 2.2-cm deep fluid collection in Morison’s pouch as well as fluid in the pelvis would have a score of 3.2. The authors found that an US score greater than or equal to 3 was predictive of a therapeutic operation. They subsequently prospectively validated the scoring system and determined that the majority (87%) of patients with an US score >3 required a therapeutic laparotomy. The hemoperitoneum score was found to be a better predictor of therapeutic laparotomy than either initial blood pressure or base deficit.(17) Independent of the hemoperitoneum score, any hemodynamically unstable patient with a positive FAST should be brought emergently to the operating room for exploratory laparotomy.
