Abstracts

Animal studies suggest that acidosis is a metabolic consequence of convulsive status epilepticus (SE). This study examines the factors associated with acidosis in human SE cases, and its effect on mortality. The population-based Richmond, Virginia, SE Database was used, and 455 SE cases with metabolic profiles during SE were identified. Acidosis was defined as serum bicarbonate level of [lt]20 mEq/L. Multivariate analyses were performed to identify the predictors of acidosis, and to determine whether acidosis predicts mortality in the presence of the other variables. Parameters were: age, sex, race, SE type, etiology, location of SE onset, mortality, and the duration of seizure activity at the time the blood sample was drawn (time to lab). Similar analyses were performed on a subset of cases (N=296) for which pH during SE was available. Time to lab was not associated with degree of acidosis. Acidosis (bicarbonate [lt]20 mEq/L) occurred significantly more often in the setting of generalized convulsive SE (GCSE) (44%) compared with partial SE (17%) or nonconvulsive SE (26%) (p[lt]0.002). Mortality was significantly higher in acidotic cases (43%) than nonacidotic cases (35%) (p[lt]0.05). In the multivariate analysis, these were the only two variables that remained significantly associated with acidosis (Odds Ratio (O.R.)=3.2 for GCSE vs. partial SE, and O.R. = 1.8 for fatal vs. nonfatal cases). In the analysis of mortality, acidosis remained a significant predictor (O.R. 2.0), along with etiology (hypoxia/anoxia), and age (O.R.=1.5 per year of increasing age). Low pH ([lt]7.2) was not an independent predictor of mortality associated with SE. A minority of GCSE cases were acidotic, but acidosis was significantly more common in GCSE than in other types of SE. Low bicarbonate level independently predicted mortality in SE cases. (Supported by NIH P01-NS25630)