Traumatic brain injury and β-blockers: not all drugs are created equal.

BACKGROUND: Dysautonomia in traumatic brain injury patients may contribute to secondary injury. We hypothesize that propranolol is the best β-blocker (BB) to block the excess catecholamines and improve mortality in this patient population.
METHODS: Patients with traumatic brain injury admitted during a 48-month period who received BB were compared with those who did not after excluding patients who received preinjury BB, deaths within 48 hours, and head Abbreviated Injury Scale (AIS) score of less than 3 or greater than 5. In addition, propranolol was also compared with all other BBs.
RESULTS: A total of 1,755 patients with traumatic brain injury were identified during the study period after exclusions. Patients who received BB (427) were older (49 years vs. 40 years; p < 0.0001), were more severely injured (Injury Severity Score [ISS], 30 vs. 24; p < 0.001), and had a more severe head injury (head AIS score, 4.2 vs. 4.0; p < 0.001). By univariate analysis, BB patients had a higher mortality (13% vs. 6%; p < 0.001); after adjusted analysis, no difference was identified (adjusted odds ratio, 0.850; 95% confidence interval, 0.536-1.348). Seventy-eight patients (18%) received propranolol during the study period. Propranolol patients were younger (30 years vs. 53 years; p < 0.001) but more severely injured (ISS, 33 vs. 29; p = 0.01; head AIS, 4.5 vs. 4.2; p < 0.001), with longer stay (44 days vs. 26 days, p < 0.001). Mortality was less in the propranolol group (3% vs. 15%, p = 0.002). Adjusted analysis confirmed the protective effect of propranolol (adjusted odds ratio, 0.199; 95% confidence interval, 0.043-0.920).
CONCLUSION: Propranolol is the best BB to limit secondary injury and decrease mortality in patients with traumatic brain injury. LEVEL OF EVIDENCE: Therapeutic, study level III.