To determine whether elevations in blood glucose levels were related to neurologic outcomes following severe brain injuries in children, 54 patients 16 years of age or younger admitted to a regional trauma center with a Glasgow Coma Scale score of 8 or less over a 2-year period were retrospectively reviewed. The mean initial blood glucose level on hospital admission was significantly higher in the 16 patients with outcomes of death or vegetative state in comparison with that of the 38 patients with outcomes of good recovery, moderate disability,or severe disability (288 mg/100 mL vs. 194 mg/100 mL, t = -2.74, p = 0.01). Blood glucose levels correlated significantly with indicators of the severity of the brain injury, which were also related to outcome. In contrast, blood glucose levels did not correlate with indicators of the severity of the extracranial injuries, although the latter were significantly related to outcome. Logistic regression analysis resulted in a model for prediction of outcome which included the Glasgow Coma Scale score on admission and the initial blood glucose level. The odds ratio of a poor outcome in this model in patients with blood glucose levels greater than or equal to 250 mg/100 mL relative to those with lower levels was 8.3 (95% confidence interval 1.3-53.6). A simple prognostic score was derived from the logistic regression which improved upon the prediction of outcome using the Glasgow Coma Scale score alone in those patients with initial blood glucose levels greater than or equal to 250 mg/100 mL.(ABSTRACT TRUNCATED AT 250 WORDS)