Effects of off pump coronary-artery-bypass surgery on hemodynamics and metabolism / 中华麻醉学杂志

ABSTRACT

ve To compare the effects of coronary-artery-bypass (CAB) surgery with and without cardiopulmonary bypass(CPB) on hemodynamics and the function of the grafts. Methods Thirty-five patients undergoing elective CAB surgery were studied. CAB was performed either with hypothermic CPB (n = 15) or without CPB(off-pump, n = 20) . The patients were premedicated with intramuscular pethidine 50 mg and scopolamine O.3mg. Anesthesia was induced with intravenous midazolam 5-15mg, fentanyl 5-20?g?kg and pancuronium 0.1 mg?kg-1 or pipecuronium 0.1 mg?kg-1 and maintained with iv infusion of fentanyl 6-10?g?kg-1, propofol 2-4mg?kg-1?h-1 and intermittent boluses of pancuronium, midazolam supplemented with 1%-1.5% isoflurane inhalation. In off-pump group naso-pharyngeal T?was maintained at 37.2℃ during operation. The amount of heparin used was equal to about one-third of amount used during CPB and ACT was maintained above 250 seconds. MAP was maintained at 70-90 mm Hg. While blood vessel was being grafted onto the coronary arteries heart rate was maintained at 60-80 bpm, otherwise esmolol 10-20mg was given iv every 5 min until it was satisfactorily controlled. In CPB group, during CPB naso-pharyngeal T?was maintained at 32℃-34℃, MAP at 50-70 mm Hg and blood gases and electrolytes within normal range. Right radial artery was cannulated and 7.5F Swan-Ganz catheter was inserted via internal jugular vein into pulmonary artery for hemodynamic monitoring and blood gas analysis. ECG, SpO2 were continuously monitored during operation. At the end of operation in patients with internal mammary artery used as graft, the flow rate of grafts was measured with 3mm Doppler probe.Results (1) After CAB cardiac index (CT) increased significantly in off-pump group(P0.05) . (3) There was no significant difference in the blood flow of artery graft and myocardial oxygen delivery (MDO2), and consumption ( MVO2) as well as MDO2/MVO2 between the two groups. Conclusions Off-pump CAB surgery has less effects on hemodynamics but systemic and myocardial oxygen delivery and consumption are similar between the two groups.