Is field hypotension a reliable indicator of significant injury in trauma patients who are normotensive on arrival to the emergency department?

There is a subset of trauma patients who are hypotensive in the field but normotensive on arrival to the emergency department (ED). Our objective was to evaluate the presence, type, and severity of injuries in these patients. Data were retrospectively reviewed from patients treated at a level 1 trauma center over 1 year. Hypotension was defined as systolic blood pressure (SBP) less than 90 mm Hg. Forty-seven patients were included. The mechanism of injury was blunt in 37 patients and penetrating in 10. The average field SBP was 76 +/- 11 mm Hg. The average SBP on arrival to the ED was 120 +/- 19 mm Hg. The average injury severity score (ISS) was 16.3 +/- 10.3 (range, 1-43). Twenty-four patients (51%) had significant injury (ISS > or = 16). Nine patients (19%) had critical injury (ISS > or = 25). Twenty-six patients (55%) required surgery, and 43 (91%) required ICU admission. Common injury sites included the head and neck (57%), thorax (44%), pelvis and extremities (40%), and abdomen (34%). Overall mortality was 10 per cent (n = 5). All patients that died had significant head and neck injuries (AIS > or = 3). Field hypotension was a significant marker for potential serious internal injury requiring prompt diagnostic workup.