Pharmacokinetics of propofol when combined with remifentanil in patients with liver cirrhosis

Abstract

Objective To investigate the pharmacokinetics of propofol when combined with remifentanil in patients with liver cirrhosis.Methods Ten patients (5 males, 5 females) with liver cirrhosis scheduled for endoscopic esophageal varix ligation (test group) and 10 cases (5 males, 5 females) with normal liver function scheduled for gastroscopy (control group), aged 18-55 yr, weighing 40-75 kg, were studied. The patients were unpremedicated. All the patients received iv injection of propofol 1.5 mg/kg and remifentanil 0.5 μg/kg, and 5 min later propofol 0.5 mg/kg and remifentanil 0.2 μg/kg was given again. Blood samples were taken from radial artery before administration and at 2, 5, 10, 15, 20, 30, 45, 60, 80 and 120 min after administration for determination of the plasma propofol concentration using gas chromatography-mass spectrography. The pharmacokinetic parameters were calculated using DAS 2.0 software.Results The pharmacokinetics of propofol was best described by a three-compartment open model. There was no significant difference in the distribution half-life, elimination halflife , terminal half-life, area under the curve and transfer rate constant between the two groups ( P ＞ 0.05) . The apparent volume of distribution of propofol and clearance were significantly increased in test group compared with control group (P ＜0.01) .Conclusion When propofol combined with remifentanil is used in patients with liver cirrhosis, the apparent volume of distribution of propofol and clearance are significantly increased, while no changes in the other pharmacokinetic parameters are found. Key words: Propofol; Piperidines; liver cirrhosis; Pharmacokinetics