Beta blockers in traumatic brain injury: a systematic review and meta-analysis

BACKGROUND: Traumatic brain injury (TBI) is a major cause of death and disability worldwide. Beta blockers have shown promise in improving mortality and functional outcomes after TBI. The aim of this article is to synthesize the available clinical data on the use of beta blockers in acute TBI. METHODS: A systematic search was conducted through MEDLINE, Embase, and Cochrane Central Register of Controlled Trials for studies including one or more outcomes of interest associated with use of beta blockers in TBI. Independent reviewers evaluated the quality of the studies and extracted data on all patients receiving beta blockers during their hospital stay compared with placebo or non-intervention. Pooled estimates, CIs, and risk ratios (RRs) or ORs were calculated for all outcomes. RESULTS: 13 244 patients from 17 studies were eligible for analysis. Pooled analysis demonstrated a significant mortality benefit of overall use of beta blocker (RR 0.8, 95% CI 0.68 to 0.94, I(2)=75%). Subgroup analysis of patients with no preinjury use of beta blocker compared with patients on preinjury beta blockers showed no mortality difference (RR 0.99, 95% CI 0.7 to 1.39, I(2)=84%). There was no difference in rate of good functional outcome at hospital discharge (OR 0.94, 95% CI 0.56 to 1.58, I(2)=65%); however, there was a functional benefit at longer-term follow-up (OR 1.75, 95% CI 1.09 to 2.8, I(2)=0%). Cardiopulmonary and infectious complications were more likely in patients who received beta blockers (RR 1.94, 95% CI 1.69 to 2.24, I(2)=0%; RR 2.36, 95% CI 1.42 to 3.91, I(2)=88%). Overall quality of the evidence was very low. CONCLUSIONS: Use of beta blockers is associated with decreased mortality at acute care discharge as well as improved functional outcome at long-term follow-up. Lack of high-quality evidence limits definitive recommendations for use of beta blockers in TBI; therefore, high-quality randomized trials are needed to further elucidate the utility of beta blockers in TBI. PROSPERO REGISTRATION NUMBER: CRD42021279700.