The present study was designed to investigate the possible effect of chronic alcohol intake on propofol and remifentanil requirements, which was determined by quantifying the 50% (EC50) and 95% (EC95) effective effect-site concentrations for propofol and remifentanil at loss of consciousness (LOC) and after a painful stimulus.
Thirty male patients (alcoholic group; n = 30) with chronic alcoholism and 30 patients (control group; n = 30) with a history of small alcohol intake were anaesthetized with propofol and remifentanil by target-controlled infusion. The predicted drug concentrations and Bispectral Index (BIS) values were recorded at LOC and after no response to painful stimuli.
The EC50 and EC95 of propofol at LOC in alcoholic group were 3.15 [95% confidence interval (CI), 2.77–3.37] and 4.05 (95% CI, 3.18–5.26) μg/ml, respectively, and those of the control group were 2.21 (95% CI, 1.92–2.86) and 3.04 (95% CI, 2.45–4.64) μg/ml, respectively. The EC50 and EC95 of remifentanil measured after no response to painful stimuli in the alcoholic group were 3.02 (95% CI, 2.70–3.38) and 4.98 (95% CI, 4.56–5.89) ng/ml, respectively, and those of the control group were 2.95 (95% CI, 2.68–3.33) and 4.86 (95% CI, 4.55–5.92) ng/ml, respectively. The EC50 and EC95 values of propofol at LOC in the control group were significantly lower than that of the alcoholic group.
These findings suggest that the induction dose requirements of propofol are increased in alcoholic patients anaesthetized with propofol and remifentanil administered by target controlled infusion.
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