Lipid peroxidation and the use of emulsified propofol in laparoscopic surgery.

Background: Free radical-induced lipid peroxidation associated with a decrease of antioxidant capacity in plasma is observed after the deflation of the pneumoperitoneum in laparoscopic surgery. In this study, we evaluated the effect of the continuous administration of lipid peroxidation derivatives on emulsified propofol.

Methods: Two groups of 20 patients each who underwent laparoscopic surgery were studied prospectively. Maintenance of anesthesia was achieved with 66% nitrous oxide and either isoflurane or continuous propofol administration. The level of thiobarbituric acid-reactive substances (TBARS) in the plasma was determined as a measure of free radicals before and after surgery.

Results: Ten patients in the propofol group had reduced TBARS, as compared to only one in the isoflurane group (p = 0.003). There was a statistically significant difference in age between the patients with reduced TBARS and those without reduced TBARS (p = 0.009) in the propofol group.

Conclusions: Anesthesia with continuous propofol infusion in laparoscopic surgery has a significant scavenging action on the formation of free radicals and exerts its greatest antioxidant effect in patients >/=48 years of age.