Effects of sevoflurane pretreatment on inflammatory response in patients undergoing cardiac valve replacement with cardiopulmonary bypass

Abstract

Objective To investigate the effects of sevoflurane pretreatment on the inflammatory response in patients undergoing cardiac valve replacement with cardiopulmonary bypass (CPB) and the mechanism of myocardial protection.Methods Twenty NYHA class Ⅱ or Ⅲ patients of both sexes,aged ＜ 60 yr,undergoing cardiac valve replacement with CPB,were randomly divided into 2 groups (n=10 each): sevoflurane group (group S) and control group (group C).The patients were premedicated with intramuscular morphine 0.1 mg/kg and scopolamine 0.3 mg.Anesthesia was induced with iv injection of midazolam 0.05-0.08 mg/kg,fentanyl 10-15 μg/kg and pipecuronium 0.08-0.10 mg/kg.The patients were tracheal intubated and mechanically ventilated.Anesthesia was maintained with intermittent iv boluses of midazolam0.03-0.06 mg/kg,fentanyl 5-10μg/kg and pipecuronium 0.04-0.08 mg/kg.Sevoflurane was inhaled before aortic clamping and the end-tidal concentration was rapidly adjusted to 1.0％ and maintained at this level for 30 min in group S.Blood samples were taken from the central vein before skin incision,immediately after aortic clamping,immediately after aortic unclamping and at 30 min after aortic unclamping,at 2,6,12 and 24 h (T1-8) after operation for determination of the concentrations of plasma tumor necrosis factor-α (TNF-α),interleukin-6 (IL) and interleukin-8 (IL-8),intercellular adhesion molecule-1 (ICAM-1),cardiac troponin I (cTnI) and activity of creatine kinase MB (CK-MB).The requirement for cardiovascular drugs was recorded after release of aortic cross clamp.Results Compared with group C,the plasma concentrations of TNF-α,IL-6 and IL-8 were significantly decreased at T3-8,the plasma concentrations of ICAM-1 and cTnl were significantly decreased at T4-8,the activity of plasma CK-MB was significantly decreased at T8,and the requirement for cardiovascular drugs was significantly reduced after release of aortic cross clamp in group S (P ＜0.05).Conclusion Sevoflurane pretreatment can inhibit the inflammatory response and provide myocardial protection to some extent in patients undergoing cardiac valve replacement with CPB. Key words: Anesthetics,inhalation; Cardiopulmonary bypass; Myocardial; Inflammation