Blood alcohol concentration for monitoring ethanol treatment to prevent alcohol withdrawal in the intensive care unit

Abstract

Objective. Alcohol withdrawal syndrome (AWS) is a serious complication during postoperative treatment in chronic alcoholics. Despite prophylactic treatment, AWS occurs in at least 25% of these patients after elective surgery. An established protocol for the prevention of AWS is ethanol administration. The aim of this study was to evaluate possible differences in ethanol dose and levels between successfully treated patients and those who developed AWS.

Design. Prospective, observational study with retrospective post hoc analysis.

Setting. Intensive care unit (ICU).

Patients. Thirty-two alcohol-dependent patients undergoing elective or emergency surgery after trauma with postoperative admission to ICU.

Interventions. Continuous postoperative i.v. ethanol substitution.

Measurements and results. Despite treatment, 13 patients developed AWS (failure group) and therapy was successful in the other 19 patients (success group). Major complications occurred more frequently in the failure group. The total dose of ethanol treatment and ethanol levels did not differ between the groups. Ethanol levels were determined in whole arterial blood (aBAC) and simultaneously taken in venous blood (vBAC), urine (UAC) and exhaled air (EAC). The following bias and precision, compared with aBAC, were found: vBAC less than UAC less than EAC.

Conclusions. There is a high failure rate for i.v. ethanol prophylaxis. None of the methods to determine alcohol concentration were sufficient to monitor suitable ethanol treatment. It therefore seems to be more useful to titrate the individual dose for each patient by closer monitoring of the clinical status, adding additional therapy to counteract AWS if higher ethanol doses are required.