Admission base deficit and lactate levels in Canadian patients with blunt trauma

BACKGROUND Elevated base deficit (BD) and lactate levels at admission in patients with injury have been shown to be associated with increased mortality. This relationship is undefined in the Canadian experience. The goal of this study was to define the association between arterial blood gas (ABG) values at admission and mortality for Canadians with severe blunt injury. METHODS A retrospective review of 3,000 consecutive adult major trauma admissions (Injury Severity Score, ≥ 12) to a Canadian academic tertiary care referral center was performed. ABG values at the time of arrival were analyzed with respect to associated mortality and length of stay. RESULTS A total of 2,269 patients (76%) had complete data available for analysis. After exclusion of patients who sustained a penetrating injury or were admitted for minor falls (ground levels or low height), 445 had an ABG drawn within 2 hours of arrival. Patients who died displayed a higher median lactate (3.6 vs. 2.2, p < 0.0001), a worse median BD (-10 vs. -5, p < 0.0001), and a lower pH (7.23 vs. 7.31, p < 0.0001) at arrival compared with those of survivors. A statistically significant association was also observed between lactate and BD values at arrival and both mortality and length of stay (p < 0.0001). CONCLUSION Despite population differences, ABGs at admission in Canadian patients with blunt trauma accurately reflect mortality in a similar manner to the previously published literature. Survival curves with lactate and BD values at arrival should be available to all clinicians within their individual trauma centers for both acute care and quality assurance. LEVEL OF EVIDENCE Prognostic study, level III.