[Effects of Propofol on Hepatic Venous Oxygen Saturation--a Comparison with Isoflurane or Sevoflurane Anesthesia]

Background: 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.

Methods: 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.

Results: 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.

Conclusions: The results suggest that propofol increases the metabolism and oxygen consumption in the liver.