Age and outcome following traumatic coma: why do older patients fare worse?

Abstract

✓ To better understand the relationship between patient age and clinical outcome following traumatic coma, the data for 661 patients, aged 15 years or older at the time of receiving a nonpenetrating head injury, were analyzed. All patients were prospectively followed and the information was entered into the Traumatic Coma Data Bank. This information was statistically analyzed to determine trends and interactions between patient age and other prognostic indicators. Older patients had higher rates of mortality overall; vegetative survival was seen in 4.8% to 8.0% of patients and did not exhibit a trend related to age. Injury severity, as assessed by motor score or Glasgow Coma Scale score, did not significantly differ according to age. The injury mechanism was age-related, with a greater frequency of falls and pedestrian accidents in older patients. Multiple injury was less frequent in older patients. Medical complications and systemic trauma were considered to be the primary cause of death in less than 25% of patients, with the exception of those between 45 and 55 years of age. When the data were studied in univariate fashion, no factor was identified that accounts for the adverse effect of age on head-injury outcome. Multivariate logistic regression, performed to assess the combined effect of multiple variables on outcome, failed to eliminate patient age as an independent predictor. Based upon this analysis, it is likely that the effect of age on outcome following head injury is dependent upon an alteration in the pathophysiological response of the aging central nervous system to severe trauma and not an increased incidence of non-neurological complications or other clinical parameters.