ETHANOL ELIMINATION RATES IN AN ED POPULATION

Knowledge of the rate of ethanol elimination is essential in the asses sment of the intoxicated patient. Surprisingly little literature is av ailable regarding ethanol elimination rates in emergency department (E D) patients; prior studies almost exclusively examined populations of alcoholics or normal controls, Consequently, this prospective observat ional study was undertaken to assess the rate of ethanol elimination i n an ED population. Twenty-four consecutive adult ED patients clinical ly suspected of intoxication who had serum ethanol determinations draw n were enrolled. Patients underwent serial ethanol determinations via breathalyzer (Intoxilyzer 1400, CMI Inc., Owensboro, KY). Linear regre ssion analysis of the plot of decrease in ethanol level over time was performed to determine the rate of ethanol elimination. Initial ethano l levels in the 24 patients ranged from 58 to 447 mg/dL (mean, 249 +/- 109 [SD] mg/dL). Patients were observed for a minimum of 2 and a maxi mum of 9 observations (mean, 3.9 +/- 1.7), over a period of 0.5 to 12. 1 hours (mean, 4.4 +/- 3.5 h), Clinical features of intoxication were poorly correlated with ethanol level (r < .5), The rate of ethanol eli mination in the ED population was 19.6 mg/dL/h (r = .83; 95% confidenc e interval [CI], 16.9 to 22.3 mg/dL/h). Subgroup analysis found differ ences that were statistically significant but small, Multiple regressi on analysis showed that time was the major variable useful in predicti ng changes in ethanol level (P < .001), The data did not provide suffi cient evidence to indicate that a history of chronic use (P = .69), in itial level less or greater than 250 mg/dL (P = .83), or level of etha nol (P = .80), when used in a regression equation along with time, are useful variables in predicting the change in ethanol level, In conclu sion, the rate of ethanol elimination in an ED population is 19.6 (95% CI, 16.9 to 22.3) mg/dL/h, corresponding closely to rates reported in the literature for other populations; subgroups have statistically si gnificant hut clinically small differences. The prediction of ethanol elimination was not shown to be enhanced by consideration of other par ameters; the lack of predictive value of ethanol level implies a zero- order model. Copyright (C) 1995 by W.B. Saunders Company)