Comparison of effects of sevoflurane versus propofol on tourniquet-induced lower extremity ischemia-reperfusion injury in patients undergoing orthopedic operation

Abstract

Objective To compare the effects of sevoflurane versus propofol on a tourniquet-induced lower extremity ischemia-reperfusion (I/R) injury in patients undergoing orthopedic operation.Methods Fifty-four ASA Ⅰ or Ⅱ patients,aged 18-64 yr,weighing 44-85 kg,scheduled for elective orthopedic operation,were randomly assigned into 3 groups (n =18 each)∶ control group (group C),propofol group (group P) and sevoflurane group (group S).After lumbar plexus-sciatic nerve block,the laryngeal mask airway insertion was facilitated with propofol 2-4 mg/kg and anesthesia was maintained with infusion of propofol at 2-4 mg· kg-1 · h-1 during operation in group P.In group S,8 ％ sevoflurane was inhaled,the laryngeal mask airway was inserted and anesthesia was maintained with inhalation of 2％ sevoflurane during operation.A tourniquet was applied and inflated (300 mm Hg)during 15-20 min after administration of propofol or sevoflurane in groups P and S,and a tourniquet was also applied at the same time point in group C.The tourniquet was released at the end of operation.Postoperative analgesia was performed with oral meloxicam or intramuscular pethidine and VAS score was maintained ＜ 3.Blood samples were taken after admission to the operating room (T1) and 30 min after tourniquet release (T2) to determine the plasma concentrations of MDA and TNF-α.The changing rate of MDA and TNF-α concentrations was calculated.The tourniquet-related adverse events and amount of analgesics consumed within 24 h after operation were recorded.Results No tourniquet-related adverse events occurred in all the patients.Compared with group C,the plasma concentrations of MDA and TNF-α and changing rate were significantly decreased at T2 in groups P and S (P ＜ 0.05).There were no significant differences in the plasma concentrations of MDA and TNF-α and changing rate between group S and group P (P ＞ 0.05).Compared with the baseline value at T1,no significant change was found in the plasma concentrations of MDA and TNF-α at T2 in groups P and S (P ＞ 0.05),and the plasma concentrations of MDA and TNF-α were significantly increased at T2 in group C (P ＜ 0.05).There was no significant difference in the amount of analgesics consumed within 24 h after operation between the three groups (P ＞ 0.05).Conclusion Both sevoflurane and propofol can reduce a tourniquet-induced lower extremity I/R injury in patients undergoing orthopedic operation and the efficacy is comparable. Key words: Anesthetics, inhalation ; Propofol ; Tourniquets ; Reperfusion injury ; Lower extremity