Propofol attenuates formation of lipid peroxides in tourniquet-induced ischaemia-reperfusion injury

We studied 20 adult ASA I patients undergoing elective peripheral surgery allocated randomly to one of two groups. In the propofol group (n=9) anaesthesia was induced with propofol and fentanyl followed by continuous infusion of propofol. In the control group (n=11), after induction of anaesthesia with thiopentone and fentanyl anaesthesia was maintained with isoflurane. Concentrations of lipid peroxides in both plasma and muscle tissue samples were measured as thiobarbituric acid-reacting substances (TBARS). Plasma TBARS concentrations increased significantly in the control group at 1, 5, 15, 30 and 45 min after release of the tourniquet to mean 1.83 (SD 0.13), 2.00 (0.12), 2.25 (0.14), 2.30 (0.12) and 2.41 (0.14) mu mol litre(-1), respectively, compared with pre-reperfusion values (1.64 (0.14) mu mol litre(-1)). In the propofol group this was significant only at 30 min (1.85 (0.03) vs 1.74 (0.04) mu mol litre(-1)). TBARS concentrations of reperfused muscle tissue were significantly higher than pre-reperfusion concentrations in the control group (70.30 (10.06) vs 52.13 (5.73) nmol/g wet tissue). We conclude that propofol attenuated ischaemia-reperfusion-induced lipid peroxidation in the therapeutic doses used in anaesthesia.