We covered the subject of beta-blockade in traumatic brain injury last autumn in this article, where we summarised the increasing evidence that it seems to improve survival. A recently published trial (free full text) in the Journal of Trauma and Acute Care Surgery adds further credence to the role of beta-blockers in this patient group. This study by Ley et al is the largest to date, as far as we can see. It included as many as 2252 patients from 15 US and Canadian trauma centers in a multi-institutional, prospective, observational trial, where 49,7% received beta-blockers of some kind. It was up to the discretion of the treating physician whether beta-blockers were prescribed.
It revealed a lower unadjusted mortality in the beta-blocker group (13,8% vs. 17,7%). This survival benefit persisted even after adjusting for a number of potential confounders, with an adjusted odds ratio of 0,35. Background data was somewhat different between the groups, with the BB cohort being older, more likely to be admitted after a fall and more often receiving anticoagulants and pre-injury beta-blockade. Among the beta-blockers administered labetalol IV was the most common, followed by metoprolol PO, propranolol PO, metoprolol IV, and propranolol IV. The subgroup receiving propranolol seemed to have the greatest survival benefit when compared to non-BB patients (9.3% vs. 15.9%, p = 0.003), consistent with findings in earlier trials. Nearly a third of patients in the BB cohort received their medication within day 1, whereas 82,7% had received it within day 5. The most common indications for beta-blockade were hypertension (64%), prevention/treatment of autonomic hyperreactivity (27%) and tachycardia (15%). Among other endpoints, Glasgow Outcome Score in survivors was similar in both cohorts after correcting for confounding factors, while the trial showed a longer hospital stay in the BB-group.
In summation, beta-blockade seems to confer a survival advantage in TBI patients, with propranolol being the superior agent. There are few obvious downsides, save perhaps for increased LOS. The important limitation in the cumulative material on this subject is the lack of randomised controlled data to definitively support the empirical use of beta-blockers in TBI. However, with the addition of this large and well executed trial there should be ample data to justify a large multicenter RCT in the not-too-distant future.