Field hypotension in patients who arrive at the hospital normotensive: a marker of severe injury or crying wolf?

Abstract

INTRODUCTION: Trauma patients with hypotension in the field who arrive at a hospital with a normal blood pressure (BP) may not be recognized as significantly injured. METHODS: Over a 5-year period, demographic, injury severity, and disposition data were retrospectively analyzed for patients > or =16 years of age with documented hypotension in the field (systolic BP < or =90 mm Hg) and normal BP (systolic BP >90 mmHg) on hospital arrival (hypotensive group). This group was compared to patients with normal BP in the field and on hospital arrival (normotensive group). RESULTS: During the study, 2207 patients with documented BP were transported directly from the scene. Of this number 44 (2%) were assigned to the hypotensive group, 2086 (94%) were assigned to the normotensive group, and 77 (4%) patients were hypotensive on hospital arrival. The hypotensive group had a systolic BP in the field of 70 +/- 26 mmHg compared to 140 +/- 26 mmHg in the normotensive group (p < 0.0001). Arrival BP at the hospital was normal in both groups. Compared to the normotensive group, the hypotensive group had higher Injury Severity Scores (22.0 vs. 11.1, p < 0.0001), lower Glasgow Coma Scores (10.8 vs. 14.0, p < 0.0001), lower Revised Trauma Scores (65 vs. 7.4, p < 0.0O01), more emergency department deaths (7% vs. 0%, p < 0.001), longer lengths of stay in the intensive care unit (8.6 vs. 7.0 days, p < 0.0001) and hospital (14.0 vs. 7.0 days, p < 0.0001), and increased hospital mortality (18% vs. 4%, p < 0.001). LIMITATIONS: The retrospective design and exclusion of patients without documentation of BP in the field may have resulted in selection bias. CONCLUSION: Despite these limitations, field hypotension is a marker of significant injury in patients arriving at the hospital normotensive.