In this historical cohort study, survival patterns and ICU outcome of adults with blunt traumatic brain injury, admitted with Glasgow Coma Scale (GCS) score of 8 or less, undergoing ICP monitoring, and included in the APACHE III database were examined. The sample of 29 (21 males, 18 to 72 years; 8 females, 18 to 86 years), included all patients meeting inclusion criteria admitted to TICU from January, 1996 through March, 1999, and to NSICU from March, 1997 through April, 1999 at the University of Kentucky Hospital.
Mortality was 27% (N = 7) and due to neurological complications. Peak time of death was between 100 and 150 hours after ICU admission. Death was higher, but not significantly in patients with an intracranial bleed (33%) compared to those without an intracranial bleed (21 %). Younger patients died significantly earlier than older patients, r = .86, p = .01.
Intracranial pressure (ICP) was above 15 mm Hg in 6 of 7 deaths, but Kaplan-Meier survival curves were not significantly different between patients with ICP values ≤15 mm Hg or >15 mm Hg using the log-rank method. CPP was below the protocol-established limit of 70 mm Hg in 5 of 7 deaths. With patients stratified by CPP value < 0 mm Hg or ≤70 mm Hg, the difference between Kaplan-Meier survival curves was not significant using the log-rank method.
Using logistic regression, ICP, SpO2, and the APACHE III score during the first 24 hours were predictors of favorable versus unfavorable outcome as measured by the Glasgow Outcome Scale score, χ2 = 9.02 (df = 3), p = .03. The GCS score and SPO2 during the first 24 hours were the best predictors of survival, χ2 = 10.58 (df = 2), p = .005. Cox's proportional hazards regression identified the GCS score and SPO2 during the first 24 hours as predictors of time until death, χ2 = 13.28 (df = 2), p = .001. With a 10% cutoff for risk of death, the APACHE III score was 73% accurate in predicting survival and 57% accurate in predicting death.
My Research