Myocardial Protective Effects Of Sevoflurane Preconditioning In Off-pump Cornary Artery Bypass Grafting

Objective: To investigate the myocardial protective effects of sevoflurane preconditioning in off-pump coronary artery bypass grafting.Methods: 20 ASAâ…¡-â…£patients scheduled for off-pump coronary artery bypass grafting(CABG) were randomized into 2 groups(n=10),total intravenous anesthesia(TIVA) group(C group);sevoflurane preconditioning group(S group),with inhalation of sevoflurane 1 MAC for 60min after the start of surgery(baseline). All 20 patients were premedicated with oral diazepam 5^-10mg the night before surgery at 21:00 and 1h early before the surgery started;β-receptor blooker (dosage according to the patients'condition of heart rate and the usual dosage before surgery),; calcium blockers(according to the type of angina and the condition of the blood pressure before surgery);intramuscular scopolamine hydrobromide 0.3mg and morphine hydrochloride 0.2mg/kg.After into the surgery,patients lay without pillow,monitored non-invasive blood pressure , oxygen saturation of blood ,electrocardiogram and radial artery blood pressure.Anaesthesia was induced with fentanyl 10μg/kg, etomidate 0.3 mg/kg, vecuronium 0.1 mg/kg.After the patients were tracheal intubated and mechanically ventilated by Datex-Ohmeda s/5 Advance anesthesia machine with oxygen ,keep PEPCO2 between 4.26⁴.66kPa.Monitored CCO,SVO2,PAP,PCWP,CVP by Philips intellivue MP50 Edwards Lifesciences vigilance CEDV via six- cavity Swan-Ganz flow directed catheters,right supraclavicular subclavian catheterization to make sure enough liquid supply.Both of the two groups were maintained with etomidate 10μg·kg^-1·min^-1, remifentanil 0.1-0.3μg·kg^-1·min^-1, and vecuronium intermittently injected 0.03mg/kg every 30min.Before open the pericardium, nitroglycerine 0.1-0.5ug/kg/min intravenous pumping.Both of the two groups took total intravenous anesthesia , after the start of the surgery(baseline) , sevoflurane preconditioning group took a inhalation of sevoflurane 1 MAC for 60min. Heart rate(HR),mean arterial pressure(MAP),central venous pressure(CVP),pulmonary capillary wedge pressure(PCWP), cardiac output(CO) , cardiac index (CI)were recorded before the start of surgery(T1),after the surgery (T2)and 24h after surgery(T3),48h after了surgery(T4).Venous blood samples were taken every time point for determination of serum concentration of cardiac troponin I(c TnI).Results:1 The two groups were compareble with respect to HR,MAP,CVP,PCWP.(P>0.05).2 There was difference in the incidences of CO(P<0.05).Compared with group C,CO was significantly increased postoperatively in group S.3 There was difference in the incidences of CI(P<0.05).Compared with group C,CI was significantly increased postoperatively in group S.4 There was difference in the incidences of cTnI(P<0.05).Compared with group C, cTnI was lower in group S.Conclusion: Sevoflurane peconditioning exerts a certain cardioprotective effect in patients undergoing off-pump coronary artery bypass grafting.