Standard calculation of ethanol elimination rate is not sufficient to provide ethanol substitution therapy in the postoperative course of alcohol-dependent patients

Abstract

Objective: Alcohol withdrawal syndrome (AWS) is a severe complication during postoperative treatment of alcohol-dependent patients. Besides the use of clomethiazole, clonidine, and benzodiazepines, there is another possible way to prevent AWS by deliberate administration of ethanol. The appropriate dosage of ethanol has not been known up to now and it could be defined according to the average ethanol elimination rate (EER) which, from forensic analysis, is known to be 15 mg/dl per h in a normal population. However, it is questionable whether these data are suitable for the calculation of the correct dosage in alcohol-dependent patients. Design: Preliminary retrospective descriptive study. Setting: Intensive care unit of a university teaching hospital. Patients: 11 alcohol-dependent patients (9 males, 2 females, mean age 50.8 years, range 33 to 60 years). Interventions: Ethanol substitution (ES) by parenteral application. Measurements and results: Ethanol kinetics were evaluated by repeated measurement of the blood ethanol concentration (BEC) over a period of at least 6 h parallel to the administration of ethanol. The average EER was found to be 28 mg/dl per h with a standard deviation of 11 mg/dl per h. The minimum value was 18 mg/dl per h and the maximum 50 mg/dl per h. These EERs were significantly higher than the EERs known from forensic analysis. AWS was prevented in all 11 patients. Conclusions: Close control of BEC and precise adjustment of ethanol administration are necessary prerequisites for ES. The standard EER is not sufficient to define the appropriate ethanol dosage due to enormous variations in the ethanol metabolism of alcohol-dependent patients.