低温闭胸心肺转流复苏后心肺脑组织的电镜改变

Ultrastructural alterations in myocardial,pulmonary and cerebral tissues after resuscitation by cardiopulmonary bypass(CPB)

目的 观察狗心脏停搏 15min后 ,用浅低温和深低温闭胸心肺转流 (CPB)复苏后心肺脑组织的电镜改变。方法 13只实验狗分三组 ,浅低温组 (33～ 34℃ ) (n =5 ) ,深低温组 (2 6～ 2 7℃ ) (n =5 ) ,狗心脏停搏 15min后行闭胸CPB ,维持平均动脉压大于 80mmHg ,3h后取心、肺和海马组织 ,对照组 (n =3)停搏 15min后立即取组织。结果 浅低温组海马组织的神经元数为 (4 6± 0 9)个 ,明显少于深低温组 (13 6± 5 2 )个 (P <0 0 5 )和对照组 (8 3± 4 7)个 ;少突胶质细胞核平均直径为 (5 86± 0 80 ) μm ,显著大于深低温组 (3 94± 0 90 ) μm(P <0 0 1)和对照组 (4 5 6± 1 0 35 ) μm(P <0 0 5 ) ,细胞膜破损明显 ;肺表面活性物质减少 ,毛细血管内皮细胞连接松弛。深低温组心肌肌原纤维变细、变稀 ,部分断裂 ,明显受损。结论 狗心脏停搏 15min后 ,浅低温闭胸CPB结合头部深低温或深低温闭胸CPB结合心肌保护治疗 。

Objective To observe ultrastructural changes in myocardial,pulmonary and hippocampal tissues after resuscitation by closed chest CPB with mild and deep hypothermia following 15 minutes cardiac arrest in dogs.Methods After 15 minutes cardiac arrest by KCl-induced ten dogs were resuscitated with the use of mild hypothermia(33～34℃) chest closed CPB in group 1 (n=5) and with deep hypothermia (26～27℃) in group 2 (n=5). The mean arteral pressures were maintained higher than 80 mmHg during CPB.The hippocampal,myocardial and pulmonary tissues were studied by electromicroscopy after 3hrs of CPB in group 1 and in group 2,in group 3 (n=3) which was controlled after 15 minutes cardiac arrest.Results In group 1,the numbers of neuron were (4 6±0 9) less than (13 6±5 2) in group 2 (P<0 01) and (8 3±4 7) in group 3,the average diameters of nuclei in oligodendrocytes were (5 086±0 80) μm more than (3 944±0 90) μm in group 2(P<0 01) and (4 563±1 035) μm in group 3(P<0 05),the broken cell membranes in oligodendrocytes were found,intra-aoveolar pulmonary surfactants were decreased,pulmonary vascular endotheliums were showed weak intercellular connections.In group 2,the thinned and fragmentation of myogenic fibrils.Conclusions Resuscitation by mild hypothermia CPB with head deep hypothermia or by deep hypothermia CPB with myocardial protection may be more effective after prolong cardiac arrest.