Initial venous lactate levels in patients with isolated penetrating extremity trauma: a retrospective cohort study.

INTRODUCTION: Elevated initial lactate levels have been shown to be associated with severe injury in trauma patients, but some patients who do not appear to be in shock also presented with elevated lactate levels. We hypothesized that in hemodynamically stable patients with isolated penetrating extremity trauma, initial lactate level does not predict clinically significant bleeding. METHODS: A 5-year institutional database review was performed. Hemodynamically stable patients (HR < 101, SBP > 90) with isolated penetrating extremity trauma with an initial lactate sent were included. The exposure of interest was captured as a dichotomous variable by initial lactate level normal (N ≤ 2.2 mEq/L), elevated (E > 2.2 mEq/L). The primary outcome measurement was clinically significant bleeding, defined by need for intervention (operation, angioembolization, or transfusion) or laboratory evidence of bleeding (presenting Hg < 7 g/dL, or Hg decrease by >2 g/dL/24 h). Chi-squared and Mann-Whitney tests were used to compare variables. RESULTS: A total of 132 patients were identified. There were no differences in demographics or mechanism of injury between the N (n = 43, 7%) and E (n = 89, 14%) groups. Median lactate levels were 1.6 (IQR 1.2-1.9) mEq/dL vs. 3.8 (IQR 2.8-5.2) in the N and E groups, p < 0.001. Lactate was elevated in 89 (67%) patients but was not associated with clinically significant bleeding (37% elevated vs. 39 % not elevated p = 0.82). CONCLUSIONS: In hemodynamically stable patients with isolated penetrating trauma to the extremity, elevated initial venous lactate levels (>2.2 mEq/L) are not associated with bleeding or need for interventions. Clinical judgment remains the gold standard for evaluation and management of these patients.