Moderate and severe traumatic brain injury: Effect of blood alcohol concentration on Glasgow Coma Scale score and relation to computed tomography findings

Abstract

1. The Rotterdam CT score based on admission CT scan was used to adjust for brain injury severity (best score 1 and worst score 6) by stratifying patients into 2 brain injury severity groups (Rotterdam CT scores of 1-3 and 4-6). Results Of all patients with measured BAC, 91% had intracranial CT findings and 43% had BAC > 0 mg/dl. The median GCS score was lower in the alcohol-positive patients (6.5, interquartile range [IQR] 4-10) than in the alcohol-negative patients (9, IQR 6-13; p < 0.01). No significant differences were found between alcohol-positive and alcohol-negative patients regarding other injury severity variables. Increasing BAC was a significant predictor of lower GCS score in a dose-dependent manner in age-adjusted analyses, with OR 2.7 (range 1.4-5.0) and 3.2 (range 1.5-6.9) for the 2 highest BAC groups (p < 0.01). Subgroup analyses showed an increasing effect of BAC group on GCS scores in patients with Rotterdam CT scores of 1-3: OR 3.1 (range 1.4-6.6) and 6.7 (range 2.7-16.7) for the 2 highest BAC groups (p < 0.01).No such relationship was found in patients with Rotterdam CT scores of 4-6 (p = 0.14-0.75).Conclusions Influence of alcohol significantly reduced the GCS score in a dose-dependent manner in patients with moderate and severe TBI and with Rotterdam CT scores of 1-3. In patients with Rotterdam CT scores of 4-6, and therefore more CT findings indicating increased intracranial pressure, the brain injury itself seemed to overrun the depressing effect of the alcohol on the CNS. This finding is in agreement with the assumption of many clinicians in the emergency situation.