Beta-blockers may cut mortality in patients with TBI.
Although patients on beta-blockers in this study were older and more severely injured than were those not taking beta-blockers, mortality rates for the two groups were similar, Dr. Thomas J. Schroeppel said at the annual meeting of the American Association for the Surgery of Trauma. "This simple and inexpensive intervention may have a profound effect on outcome in these severely injured patients."
Dr. Schroeppel and his coinvestigators reviewed the trauma registry at an urban level 1 trauma center for blunt traumatic brain injury (TBI) from January 2005 to December 2007. Patients who received at least one dose of beta-blockers were identified on the basis of the hospital pharmacy order database.
The researchers identified 2,601 patients with blunt TBI, of which 510 (19.6%) had received at least one dose of beta-blockers. The primary indication for beta-blocker use was hypertension. A total of 18% of patients were already on beta-blockers when they entered the hospital. There was no difference in mortality between patients already on beta-blockers at admission and those who got them afterward, according to Dr. Schroeppel, assistant professor of surgery at the University of Tennessee in Memphis.
Overall, the TBI patients were predominantly male (80%) with a mean age of 41 years, a mean admission Glasgow Coma Scale (GCS) of 11, and a mean Injury Severity Score (ISS) of 26. Overall mortality was 16%, Dr. Schroeppel said.
Patients on beta-blockers were significantly older (51 years vs. 38 years) and had significantly more severe head injury, measured by the head Abbreviated Injury Score (4.1 vs. 3.8) and the GCS (10 vs. 11). Significantly more patients on beta-blockers required transfusions than did the control group (66% vs. 27%). In addition, patients on beta-blockers had longer hospitals stays (28 days vs. 11 days) and nearly twice the incidence of ventilator-associated pneumonia, compared with the control group (48% vs. 27%).
Nonetheless, the 15% mortality rate among patients on beta-blockers was not significantly different from the 16% rate among controls.
Using multivariate logistic regression analysis to adjust for age, ISS, admission GCS, and transfusions, the researchers found that the use of beta-blockers was associated with an odds ratio for mortality of 0.36.
In subsequent analyses, the researchers excluded patients who died or had care withdrawn within the first 24-48 hours after admission in order to eliminate any potential survivor bias (i.e., only those who lived long enough received their beta-blockers). This showed a significant odds ratio for mortality of 0.37 in beta-blocker users. Likewise, after exclusion of patients who died or had care withdrawn within the first 24 hours, the patients taking beta-blockers had a significant 0.67 odds ratio for mortality. However, after the patients who died or had care withdrawn within the first 48 hours were excluded, the odds ratio for mortality was 0.77 with beta-blocker use, not a significant difference.
Catecholamine surge following TBI is associated with infectious morbidity and potentially preventable mortality. Previous studies have supported the protective effect of beta-adrenergic blockade in patients with TBI, which decreases cerebral metabolism, vasospasm, and oxygen consumption.
The researchers had hypothesized that suppression of the catecholamine surge in multiply injured TBI patients with beta-adrenergic blockade decreases mortality.
Dr. Schroeppel reported that he has no relevant financial relationships.
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|Publication:||Clinical Psychiatry News|
|Date:||Nov 1, 2009|
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