Etomidate anaesthesia in patients with cirrhosis of the liver: pharmacokinetic data.

Five patients undergoing endoscopic injection of oesophageal varices were anaesthetised with etomidate 0.2 mg/kg followed by an infusion at a rate of 20 micrograms/kg/minute. Fentanyl 100-200 micrograms was also given intravenously and the patients' lungs were ventilated with oxygen in air. The postinfusion plasma etomidate concentration was described by a three compartment model with a mean half-life of 540 minutes (SEM 66.9) and volume of distribution of 8.9 litres/kg (SEM 0.6). Clearance was 12.7 ml/kg/minute (SEM 2.3). Compared to results in the literature obtained from normal patients, these cirrhotic patients had normal clearance rates, but the distribution volume and elimination half-life were twice as great. This suggests that cirrhotic patients metabolise etomidate normally, but the volume of distribution is doubled, thus resulting in prolonged elimination half-lives.