Effect of different sevoflurane postconditioning on myocardial injury in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass

Abstract

Objective To evaluate the effect of different sevoflurane postconditioning on myocardial injury in patients undergoing coronary artery bypass grafting （CABG ） with cardiopulmonary bypass （CPB ） .Methods Seventy-five NYHA class Ⅰ or Ⅱ patients ,aged 46-72 yr ,weighing 57-90 kg ,scheduled for elective CABG with CPB ,were randomly divided into 5 groups （ n=15 each） using a random number table ：control group （groupⅠ） , postconditioning with continuous administration of 1.7% sevoflurane group （groupⅡ a ） , postconditioning with continuous administration of 3.4% sevoflurane group （group Ⅲa） ,postconditioning with interrupted administration of 1.7% sevoflurane group （Ⅱb） and postconditioning with interrupted administration of 3.4% sevoflurane group （group Ⅲb） .Sevoflurane was not given in group Ⅰ .In Ⅱa group ,after the anastomotic stomas of the internal mammary artery to anterior descending artery were released ,the patients continuously inhaled 1.7% sevoflurane for 15 min .In Ⅱb group ,after the anastomotic stomas were released .In Ⅲa group ,after the anastomotic stomas were released , the patients continuously inhaled 3.4% sevoflurane for 15 min , the patients inhaled 1.7%sevoflurane for 5 min first ,inhalation was interrupted for 5 min ,and then inhalation was recovered lasting for 5 min ,and it was 15 min in total .In Ⅲb group ,after the anastomotic stomas were released ,the patients inhaled 3.4% sevoflurane for 5 min first ,inhalation was interrupted for 5 min ,and then inhalation was recovered lasting＆nbsp;for 5 min ,and it was 15 min in total .Venous blood samples were taken for determination of the plasma creatine kinase ,creatine kinase isoenzyme-MB , lactic dehydrogenase , and cardiac troponin I concentrations before CPB and at 6 and 24 h after operation .Myocardial specimens were obtained from the right auricle before CPB and after termination of CPB for microscopic examination of the ultrastructure .Results Compared with group Ⅰ , the concentration of cardiac troponin Ⅰ was significantly decreased at 6 and 24 h after operation （ P0.05 ） .The pathological changes were significantly attenuated in sevoflurane postconditioning groups as compared with group Ⅰ ,especially in Ⅱb group . Conclusion Postconditioning with continuous administration of 3.4% sevoflurane for 15 min can attenuate myocardial damage in patients undergoing CABG with CPB . Key words: Anesthetics,inhalation; Ischemic postconditioning; Cardiopulmonary bypass; Myocardium