Beta-blocker exposure is associated with improved survival after severe traumatic brain injury

Background: Beta-blocker use in elective noncardiac surgery has been associated with a reduction in mortality and cardiovascular complications. Traumatic brain injury (TBI) is often associated with a hyperadrenergic state. We hypothesized that adrenergic blockade would confer improved survival among TBI patients. Methods: Retrospective review of the Trauma Registry of the American College of Surgeons database at a Level I trauma center was conducted. All trauma patients admitted from January 2004 to March 2005 with head Abbreviated Injury Scale score of 3 or greater were evaluated. Patients with length of stay < 4 or > 30 days were excluded. Beta-blocker exposure was defined as receiving beta-blockers for 2 or more consecutive days. Results: In all, 420 patients met inclusion criteria: 174 patients exposed to beta-blockers [BB(+)] and 246 not exposed [BB(-)]. Mean age in BB(+) group was 50 years and 36 years in BB(-) group (p < 0.001). Mean Injury Severity Score was 33.6 for BB(+) group and 30.8 for BB(-) group (p = 0.01). Predicted survival (by Trauma and Injury Severity Score) for BB(+) group was 59.1% compared with 70.3% for BB(-) group (p < 0.001). Observed mortality for BB(+) group was 5.1%, 10.8% for BB(-) group (p = 0.036). Adjusted incidence rate ratio of mortality among those exposed to beta-blockers compared with those not exposed was 0.29 (95% confidence interval). Conclusions: Beta-blocker exposure was associated with a significant reduction in mortality in patients with severe TBI. This reduction in mortality is even more impressive, considering that the BB(+) group was older, more severely injured, and had lower predicted survival.