常温不停跳冠脉搭桥对血液动力学及氧代谢的影响

Effects of off pump coronary-artery-bypass surgery on hemodynamics and metabolism

目的 比较研究常温心脏不停跳和低温体外循环心脏停跳手术对血液动力学及移植血管功能的影响。方法 35例冠脉搭桥手术病人分为心脏不停跳组（20例）和体外循环心脏停跳组（15例）。经Swan-Ganz漂浮导接Baxter CCO监测仪监测血液动力学,Doppler测定移植血管血流量,并测定全身及心肌的氧供需。结果（1）搭桥后,心脏不停跳组CI显著升高,MPAP、SV、HR无明显变化;心脏停跳组CI无明显变化,SV降低,HR和MPAP增加。搭桥后两组CO较手术前无统计学差别;（2）搭桥后两组病人CaO2和CvO2均显著下降,VO2、O2ER和VO2I呈增加的趋势,但无统计学意义;（3）搭桥后两组病人移植血管的血流量无明显差异,移植血管支配区域心肌的MDO2、MVO2和MDO2/MVO2也无明显差异。结论 常温不停跳搭桥手术对血液动力学的影响较小,而对全身氧供需的平衡及移植血管功能的影响与体外循环心脏停跳搭桥手术相似。

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 5-20μg·kg and pancuronium 0.1 mg·kg-1 or pipecuronium 0.1 mg·kg-1 and maintained with iv infusion of fentanyl 6-10μg·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(P<0.05) but there were no significant changes in MPAP, SV and HR, whereas in CPB group, there was no significant change in CT, but there was significant decrease in SV(P<0.05) and increase in HR and MPAP. There was no significant change in CO in both groups compared with the preoperative baseline level. (2) After CAB there was significant decrease in both CaO2 ( P < 0.05) and CvO2 (P<0.01) in both groups. VO2,O2ER and VO2I tended to increase but the increase was of no statistical significance(P>0.05) . (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.