100 positive patient care FAST exams from adult trauma patients met eligibility criteria. While 32.0% (95% CI: 23.5-41.6%) of positive FAST exams had FF in the LUQ, only 7.0% (95% CI: 3.2-13.3%) of patients with positive FAST exam had FF isolated to LUQ. Of all patients with FF in the LUQ (n=32), 84% of patients (n=27, 95% CI: 69.1-93.8) had fluid in the paracolic gutter, with or without FF elsewhere in LUQ,.None (95% CI: 0-7.5) had fluid seen only in splenorenal fossa, 3% (n=1, 95% CI: 0.3-13.7) had FF only above spleen. 51.0% of patients (95% CI: 41.3-60.7%) had LUQ views deemed inadequate for medical decision-making.