Effect of cocaine use on outcomes in traumatic brain injury

CONTEXT: Animal and molecular studies have shown that cocaine exerts a neuroprotective effect against cerebral ischemia. AIMS: To determine if the presence of cocaine metabolites on admission following traumatic brain injury (TBI) is associated with better outcomes. SETTINGS AND DESIGN: Level-1 trauma center, retrospective cohort. MATERIALS AND METHODS: After obtaining Institutional Review Board (IRB) approval, the trauma registry was searched from 2006 to 2009 for all patients aged 15-55 years with blunt head trauma and non-head AIS <3. Exclusion criteria were pre-existing brain pathology and death within 30 min of admission. The primary outcome was in-hospital mortality; secondary outcomes were hospital length of stay (LOS), and Glasgow Outcome Score (GOS). STATISTICAL ANALYSIS: Logistic regression was used to determine the independent effect of cocaine on mortality. Hospital LOS was compared with multiple linear regression. RESULTS: A total of 741 patients met criteria and had drug screens. The screened versus unscreened groups were similar. Cocaine positive patients were predominantly African-American (46% vs. 21%, P < 0.0001), older (40 years vs. 30 years, P < 0.0001), and had ethanol present more often (50.7% vs. 37.8%, P = 0.01). There were no differences in mortality (cocaine-positive 1.4% vs. cocaine-negative 2.7%, P = 0.6) on both univariate and multivariate analysis. CONCLUSIONS: Positive cocaine screening was not associated with mortality in TBI. An effect may not have been detected because of the low mortality rate. LOS is affected by many factors unrelated to the injury and may not be a good surrogate for recovery. Similarly, GOS may be too coarse a measure to identify a benefit.