Effects of propofol on hepatic venous oxygen saturation--a comparison with isoflurane or sevoflurane anesthesia]

We performed a comparative study of propofol versus isoflurane and sevoflurane using continuous monitoring of hepatic venous oxygen saturation (ShvO2) during upper abdominal surgery in 26 patients.Anesthesia was induced with propofol 2-2.5 mg x kg(-1) and vecuronium 0.1 mg x kg(-1). Thereafter, Swan Ganz catheters were inserted into the pulmonary artery and hepatic vein. Group P (n=26) patients received continuous propofol infusion and epidural mepivacaine injection for maintenance, while Group I (n=17) received isoflurane and Group S (n=9) received sevoflurane. Systemic oxygen extraction ratio (OERsys) and hepato-splanchnic oxygen extraction ratio (OERspl) were calculated.Heart rate, mean arterial pressure and cardiac index were unchanged after propofol infusion, and isoflurane or sevoflurane inhalation. Propofol at 8 and 10 mg x kg(-1) x h(-1) significantly decreased ShvO2 and increased OERspl, although isoflurane and sevoflurane did not change them. Mixed venous saturation and OERsys were within normal ranges during the studies.The results suggest that propofol increases the metabolism and oxygen consumption in the liver.