聚乙二醇-牛血红蛋白在体外循环中对机体血流动力学变化的研究

The Study of PEG-bHb on Hemodynamic Indexes during Cardiopulmonary Bypass

目的采用颈静脉-股动脉部分转流的体外循环(CPB)模式,比较以聚乙二醇-牛血红蛋白(PEG-bHb)代替预充液中的胶体溶液进行的体外循环与常规晶体/胶体预充液进行的CPB,对羊机体血流动力学各项指标的影响。方法随机选取13只小尾寒羊,根据CPB预充液成分的不同分为两组:实验组(P组,n=7)在CPB前经羊颈静脉放自体血(15ml/kg)后,在CPB晶体预充液中加入等量PEG-bHb,在CPB转流结束后,将保存的羊自体血输入体内;对照组(C组,n=6)则应用常规体外循环预充液方案。分别在转流开始后0、5、15、30、45、60,停机后30、60min记录心率(HR)、平均动脉压(MAP)、中心静脉压(CVP)、心输出量(CO)、左室压最大变化速率(+dp/dt)、左室压最小变化速率(-dp/dt)等血流动力学指标。术后观察羊的存活状态,存活至第7日处死后分别取心、肝、脑、肺、肾等组织以行光、电镜病理检查。结果两组HR、CVP、+dp/dt、-dp/dt在围术期无显著性差异(P>0.05);实验组中的MAP在CPB中45、60和停机后30min明显高于对照组(P<0.05);实验组中的CO在CPB中的45和停机后30min时明显高于对照组(P<0.05);实验组中的左室压力最大变化速率(+dp/dt)在45min时与对照组值有显著性差异(P<0.01)。光、电镜检查显示动物肺组织基本正常,心、肝、肾组织有轻微病理改变,但两组之间未见明显差异;两组动物脑组织均有缺血、缺氧表现,但实验组脑组织小的出血灶较对照组为少,且神经元变性较轻。结论PEG-bHb可作为一种安全有效的血液替代品维持体外循环中机体血流动力学的稳定。

OBJECTIVE The present study was designed to evaluate the effect of PEG - bHb primed into the cardiopulmonary bypass （CPB） circuits compared to erystalloid/eolloid prime solution by hemodynamic indexes during CPB in sheep. METHODS The partial CPB by jugular vein - femoral artery model was used to evaluate PEG - bHb effect as colloid substitute in prime solution. Thirteen sheep were divided randomly into two groups. In group P （ n = 7 ） , 9ml/kg PEG - bHb was added in the erystalloid prime, and equal volume of autologous animal whole blood was harvested before CPB from jugular vein, and then the harvested blood was transfused into the same animals after CPB, ; and in group C （n = 6） , which was served as control group, a erystalloid/colloid solution was used as prime solution. Hemodynamic data, included heart rate （HR） .mean arterial pressure （MAP） .cardiac output （CO） ,central venous pressure （CVP） and the differential velocity of pressure （ ＋ dp/dt. - dp/dt） were monitored at 0min .5 min, 15min .30min .45 min .and 60min during CPB; and 30min,60min after CPB. The tissue of heart,liver,lung,kidney,and brain were harvested for pathological examinations with optic and electron microscopy , RESULTS HR,CVP and - dp/dt had no significant difference between these two groups during CPB. MAP at 45min during CPB and 30min after CPB in group P was higher than in the group C（ P 〈0.05 ）. CO at 45min during CPB and 30min after CPB in group P significantly increased compared with in group C （ P 〈0.05）. ＋ dp/dt （ P 〈 0.01 ） at 45min during CPB significantly increased in the group P compared with that in group C. All animals in two groups survived until before they were killed at 7d for pathological study by optic and electron microscopy, and slight pathological changes were observed in the tissues of heart ,liver,and kidney of animals from both two groups. Approximately normal structure of lung was observed in two group animals. Pathologic changes due to insufficient blood and oxygen supply were found in brain tissues of animals from two groups, however injury of neurocyte in group P was milder than in group C. CONCLUSION PEG - bHb is effective and safe to maintain all the hemodynamic indexes, and can be used during cardiopulmonary bypass as a component in the prime solution.