The impact of beta-blocker therapy on anemia after traumatic brain injury

BACKGROUND: An increase in endogenous catecholamine levels after traumatic brain injury (TBI) is well described. Animal studies suggest that postinjury anemia is exacerbated by a persistent hyperadrenergic state. This study aims to determine if beta-blocker (BB) exposure affects anemia after TBI. STUDY DESIGN AND METHODS: We reviewed a Level I trauma registry for patients with TBI, examining markers of anemia between patients who received BB with those who did not. RESULTS: A total of 174 patients were exposed to BB (BB+) and 245 were not exposed (BB-). The mean age in the BB+ group was 50 years (vs. 36 years in BB-group, p < 0.001). The mean injury severity score was 33.6 for the BB+ group (vs. 30.8 for BB-group, p = 0.01). While BB+ patients were more likely to receive a transfusion (60.9% vs. 35.1%, p < 0.001), BB+ patients reached their nadir hemoglobin (Hb) at a later day of hospitalization and their rate of decrease in Hb was significantly slower (both p < 0.001). Choosing Hb cutoffs for anemia of both 7 and 10 g/dL, Kaplan-Meier demonstrated a significant delay in time to anemia. CONCLUSION: This study suggests beta-blockade delays anemia after TBI. Elaboration of this effect may demonstrate an additional benefit of beta-blockade after head injury.