Serial venous point-of-care lactate measurements for the evaluation and triage of undifferentiated patients with blunt trauma

Background: Lactate has prognostic use in critically ill medical and trauma patients. Although some centers use lactate in the initial evaluation of patients with obvious severe trauma, it has not been investigated as a triage tool in the initial emergency department trauma presentation. We sought to determine the use of serial point-of-care venous lactates in the assessment of blunt trauma patients. We hypothesized that elevated venous lactate at presentation, and changes in lactate, would predict severe injury and bad outcome. Methods: This prospective observational cohort study enrolled adult blunt trauma patients meeting trauma activation criteria and whose injuries occurred within 6 hours of presenting to a trauma center. Venous lactate was measured 0, 2, and 4 hours after presentation using the i-STAT point-of-care analyzer. Injury severity scores (ISSs) and outcomes were followed until discharge or 30 days. A bad outcome was defined as death, surgery, or intensive care unit admission. Results: One hundred forty-nine patients were included: 74.5% were men, 87.9% were white, and mean age is 40 years. There were 44 patients (30%) with ISS of 16 or higher and 60 (40%) with a bad outcome. Abnormal vital signs (systolic blood pressure, ≤90; Glasgow Coma Scale, ≤14; heart rate, 120; respiratory rate, ≤10 or 30) were present in only 16%, 30%, 11%, and 12% of patients with ISS of 16 or higher, respectively. Serial lactate values were higher in patients with a bad outcome or ISS of 16 or higher (P < 0.05 for all). Decreasing lactate levels were associated with improved outcomes (P = 0.036). Conclusions: Our data support the use of serial lactate measurements to aid in the initial evaluation of undifferentiated blunt trauma patients.