Prehospital hypotension in blunt trauma: identifying the "crump factor"

Trauma activation for prehospital hypotension in blunt trauma is controversial. Some patients subsequently arrive at the trauma center normotensive, but they can still have life-threatening injuries. Admission base deficit (BD)≤-6 correlates with injury severity, transfusion requirement, and mortality. Can admission BD be used to discriminate those severely injured patients who arrive normotensive but "crump," (i.e., become hypotensive again) in the Emergency Department? The purpose is to determine whether admission BD<-6 discriminates patients at risk for future bouts of unexpected hypotension during evaluation.

Retrospective chart review was performed on all blunt trauma admissions at a Level I trauma center from August 2002 through July 2007. Hypotension was defined as a systolic blood pressure≤90 mm Hg. Patients who were hypotensive in the field but normotensive upon arrival in the emergency department (ED) were included. Age, gender, injury severe score, arterial blood gas analysis, results of focused abdominal sonogram for trauma (FAST), computed tomography, intravenous fluid administration, blood transfusions, and the presence of repeat bouts of hypotension were noted. Patients were stratified by BD≤-6 or ≥-5. Statistical analysis was performed using paired t test, χ, and logistic regression analysis with significance attributed to p<0.05.

During the 5-year period, 231 blunt trauma patients had hypotension in the field with subsequent normotension on admission to the ED. Of these, 189 patients had admission BD data recorded. Patients with a BD≤-6 were significantly more likely to have repeat hypotension (78% vs. 30%, p<0.001). Overall mortality was 13% (24 of 189), but patients with repeat hypotension had greater mortality (24% vs. 5%, p<0.003).

Blunt trauma patients with repeat episodes of hypotension have significantly greater mortality. Patients with transient field hypotension and a BD≤-6 are more than twice as likely to have repeat hypotension (crump). This study reinforces the need for early arterial blood gases and trauma team involvement in the evaluation of these patients. Patients with BD≤-6 should have early invasive monitoring, liberal use of repeat FAST exams, and careful resuscitation before computed tomography scanning. Surgeons should have a low threshold for taking such patients to the operating room.