RESUMEN
Objective To explore mycocardial protection effect of sevoflurane post-conditioning in off-pump coronary artery bypass grafting (OPCABG) surgery,and the mechanism of mycocardial protection of sevoflurane post-conditioning.Methods Thirty six patients undergoing OPCABG were randomly divided into three groups:at 1.5 MAC (minimum alveolar concentration) for 5 minutes first,with an interruption control group (Cont group),sevoflurane preconditioning group (SPC group),and sevoflurane postconditioning group (SPO group).All patients were administrated by intravenous anesthetic drug,both for induction and maintenance.No special interventions were used in Cont group.However,in SPC group,12 patients inhaled sevoflurane for 10 minutes,then continued for 5 minutes,total 10 minutes before the anastomotic between mammary artery and anterior descending artery.In SPO group,12 patients inhaled sevoflurane at 1.5 MAC for 2 minutes before the anastomosis of last one coronary artery,and continued for 8 minutes.Four time points were focused on including T1 (accomplishment of induction),T2 (1 hour after the coronary revascularization),T3 (6 hour after the coronary revascularization),and T4 (24 hour after the coronary revascularization).Blood samples were drawn from the internal jugular vein for the measurement of the plasma concentrations of TNT-hs (highly sensitive cardiac troponin T),CK-MB (creatine phosphokinase isoenzyme),NT-proBNP (N-Terminal fragment of the prohormone Brain-Type Natri-uretic Peptide),and TNF-α (tumornecrosis factor-α).Results All the patients completed the trials without significant adverse effects.The age,gender,ejection fraction,and operative time among three groups were no statistically significant difference (P ＞ 0.05).Stay time in postoperative ICU and hospital were significantly less than Cont group (P ＜ 0.05).Compared to the pre-operative baseline,all patients'plasma concentrations of TNT-hs,CK-MB,NT-proBNP,and TNF-α were significantly increased at 1 h,6 h,and 24 h after coronary revascularization (P ＜0.05).TNT-hs in Cont group showed a persistent increase,while in other two groups (SPC and SPO),TNT-hs reached the peak concentrations at 6 hours after the coronary revascularization,which were same with CK-MB,TNF-α,and MDA in all groups;NT-proBNP reached the peak at coronary revascularization after 24 h.Compared to Cont group,TNT-hs,CK-MB,and TNF-α in groups SPC and SPO were significantly lower at 6 h,24 h after coronary revascularization; NT-proBNP was significantly lower only at 24 h after coronary revascularization.Conclusions Sevoflurane post-conditioning in OPCABG has identified myocardial protection,which was comparable with sevoflurane preconditioning.