Effects of remifentanil on lipid peroxidation during hemorrhagic shock-induced acute lung injury in rabbits

Objective To investigate the effects of remifentanil on lipid peroxidation druing hemorrhagic shock-induced acute lung injury （ALI） in rabbits. Methods Thirty-two healthy adult rabbits weighing 2.0-2.5 kg were randomly divided into 4 groups （n = 8 each）： sham operation group （group S）; ALI group; low-dose remifentanil group （group LR）; high-dose remifentanil group （group HR）. The left femoral artery was cannulated for blood-letting and blood sampling. The right femoral artery was cannulated for remifentanil administration. The model of hemorrhagic shock was established by modified Wigger＇ s methods. In group S, only cannulation was performed. In group LR and HR, remifentanil was infused intraperitoneally at 0.66 and 1.32 μg·kg-1 ·min-1 15 min before blood-letting respectively, while group ALI received equal volume of normal saline instead. Arterial blood samples were taken at 0, 20,70 and 100 min after blood-letting （T1-4） for blood gas analysis. The animals were then sacrificed and the lungs were immediately removed for histological examination with light microscope and determination of W/D lung weight ratio, MDA content and SOD activity. Results W/D ratio and MDA content were significantly increased, while SOD activity was significantly decreased in group ALI compared with group S （P 〈0.05）. The pH value at T2 and PaO2 at T2-4 in group LR and the pH value and PaCO2 at T2-4 in group HR were significantly higher than those in group ALI （P 〈 0.05）. W/D ratio and MDA content were significantly lower,while SOD activity was significantly higher in group LR and HR than in group ALI, and in group HR than in group LR （P 〈 0.05）. Remifentanil infusion significantly attenuated the pathologic changes in a dose-dependent manner. Conclusion Remifentanil pretreatment can attenuate hemorrhagic shock-induced ALI through inhibiting lipid peroxidation in rabbits. Key words: Piperidines; Respiratory distress syndrome,adult; Shock,hemorrhagic; Lipid peroxidation