Alcohol is associated with a lower pneumonia rate after traumatic brain injury

Background: Recent evidence supports the beneficial effect of alcohol on patients with traumatic brain injury (TBI). Pneumonia is a known complication following TBI; thus, the purpose of this study was to evaluate the effects of alcohol on pneumonia rates following moderate to severe TBI. Methods: From 2005 to 2009, the Los Angeles County Trauma Database was queried for all patients ≥14 y of age with isolated moderate to severe TBI and admission serum alcohol levels. The incidence of pneumonia was compared between TBI patients with and without a positive blood alcohol concentration (BAC) level. The study population was then stratified into four BAC levels: None (0 mg/dL), low (0-100 mg/dL), moderate (100-230 mg/dL), and high (≥230 mg/dL). Pneumonia rates were compared across these levels. Results: A total of 3547 patients with isolated, moderate to severe TBI were evaluated. Nearly 66% tested positive for alcohol. The pneumonia rate was significantly lower in the TBI patients who tested positive for alcohol (2.5%) compared with those who tested negative (4.0%, P = 0.017). The pneumonia rate also decreased across increasing BAC levels (linear trend P = 0.03). After logistic regression analysis, a positive ethanol (ETOH) level was associated with a reduced incidence of pneumonia (AOR = 0.62; 95%CI: 0.41-0.93; P = 0.020). Conclusion: A positive serum alcohol level was associated with a significantly lower pneumonia rate in isolated, moderate to severe TBI patients. This may explain the observed mortality reduction in TBI patients who test positive for alcohol. Additional research is warranted to investigate the potential therapeutic implications of this association.