高龄患者瓣膜手术长时间体外循环管理

Management of long-time cardiopulmonary bypass on aged patients with valve replacement operations

目的探讨高龄瓣膜手术长时间体外循环转流的原因、对代谢影响,以提高CPB转流技术和管理水平。方法21例58～76岁老年患者在全麻低温CPB下行瓣膜置换术,CPB采用中度低温,心肌保护应用4:1(血:晶体)高钾(20mmol/L)含镁(20mmol/L)停搏液正灌或与逆灌联合,开放升主动脉前温血灌注;CPB中维持灌注流量2.4～2.8L/(m2·min)和平均动脉压(MAP)60～90mmHg;预充白蛋白20g。CPB中应用超滤、悬浮红细胞、抑肽酶、速尿。结果本组21例CPB转流时间180～350min,升主动脉阻断55～200min,存活18(占85.7%)例,死亡3例。结论4:1高钾含镁停搏液正灌或与逆灌联合、开放升主动脉前温血灌注为有效的心肌保护方法;CPB中维持高灌注流量和平均动脉压,应用白蛋白、抑肽酶、速尿等有助于脑、肺、肾等重要脏器的保护;随CPB时间延长,血糖及乳酸有不断上升的趋势,并早于血气和SVO2的变化,乳酸持续升高不降,则预后不良。

Objective To summarize the clinical experience of long-time cardiopulmonary bypass （CPB）in valve replacement procedure on aged patients.Methods 21 patients ranged from 58 to 76 years were received valve replacement procedure under hypothermic CPB after systemic anesthesia. Myocardial protection was performed used blood cardioplegia. High perfusion flow 2.4- 2.8L/（m^2.min） and high mean arterial pressure 60- 90mmHg during CPB.Results CPB time was 180- 350min, aortic cross - clamp time was 55- 200min. Three patients were died,the others recovered.Conclusion It was effective that myocardial protection performed by anterograde or by combination with anterograde and retrograde cardioplegia perfusion using 4：1 hyperkalaemic, hypermagnesemic cold blood cardioplegia, or by warm blood anterograde cardioplegia before releasing the aortic cross-clamp. It helped to protected brain, lung and kidney that using albumin, aprotinin and furosemide during CPB. The high level of carbohydrate and lactic acid indicates more risk during long-time CPB.