Beta-blockade is not associated with improved outcomes in isolated severe extracranial injury: an observational cohort study

BACKGROUND: There is evidence supporting the use of beta-blockade in patients with traumatic brain injury. The reduction in sympathetic drive is thought to underlie the relationship between beta-blockade and increased survival. There is little evidence for similar effects in extracranial injuries. This study aimed to assess the association between beta-blockade and survival in patients suffering isolated severe extracranial injuries. METHODS: Patients treated at an academic urban trauma centre during a 5-year period were retrospectively identified. Adults suffering isolated severe extracranial injury [Injury Severity Score (ISS) ≥ 16 with Abbreviated Injury Score of ≤ 2 for any intracranial injury] were included. Patient characteristics and outcomes were collected from the trauma registry and hospital medical records. Patients were subdivided into beta-blocker exposed and unexposed groups. Patients were matched using propensity score matching. Differences were assessed using McNemar’s or paired Student’s t test. The primary outcome of interest was 90-day mortality and secondary outcome was in-hospital complications. RESULTS: 698 patients were included of whom 10.5% were on a beta-blocker. Most patients suffered blunt force trauma (88.5%) with a mean [standard deviation] ISS of 24.6 [10.6]. Unadjusted mortality was higher in patients receiving beta-blockers (34.2% vs. 9.1%, p < 0.001) as were cardiac complications (8.2% vs. 1.4%, p = 0.002). Patients on beta-blockers were significantly older (69.5 [14.1] vs. 43.2 [18.0] years) and of higher comorbidity. After matching, no statistically significant differences were seen in 90-day mortality (34.2% vs. 30.1%, p = 0.690) or in-hospital complications. CONCLUSIONS: Beta-blocker therapy does not appear to be associated with improved survival in patients with isolated severe extracranial injuries.