Effect of Sevoflurane Preconditioning on Inflammatory Cytokines andOxygen Radicals During Single Lung Ventilation in Patients with Lung Cancer

Objective: To observe the effect of sevoflurane preconditioning on inflammatory cytokines and oxygen radicals during single lung ventilation (SLV) in patients with lung cancer and to discuss the mechanism of sevoflurane induced lung protection. Methods: Thirty patients, ASA I or II, with non-small-cell lung cancer underwent pulmonary surgeries were randomized into two groups: sevoflurane preconditioning group (group S, n=15) and control group (group C, n=15). After general anaesthesia induction. A double-lumen tube was placed and the position was checked by a fibre optic bronchoscope. During the mechanical ventilation, patients in group S, received sevoflurane at 1.0 minimum alveolar concentration (MAC) for 30 min as a preconditioning and then replaced by oxygen for a complete rapid gas exchange to reduce the sevoflurane inhalation concentration to 0 before SLV. While in group C, only intravenous anaesthetic agents, fentanyl and propofol, were administrated before SLV. Blood concentrations of TNF-α, IL-6, IL-8, SOD and MDA were measured at Post-induction of anaesthesia (T1), 30 min after SLV in the lateral position (T2), 60 min after SLV in the lateral position (T3), and at the end of the operation (T4). Results: When compared with Tl, the concentrations of TNF-α, IL-6 and MDA in both groups and the IL-8 in group S were significantly increased at T2-T4 (P<0.05), while the expression of SOD in two groups were decreased significantly(P<0.05). The concentrations of TNF-α, IL-6, IL-8 and MDA in group S were decreased significantly at T2-T4 (P<0.05 or P<0.01) when compared with those in group C. The activity of SOD in group S was significantly increased at T3 and T4 (P<0.05). Conclusion: Sevoflurane preconditioning may moderate the release of inflammatory cytokines to inhibit the inflammatory reaction and may reduce the lipid peroxidation by inhibiting the generation of oxygen free radical. It may protect the lung from the injury during SLV.