老年患者心脏手术体外循环技术的应用

Application of cardiopulmonary bypass technique in elderly patients

目的探讨老年患者心脏手术体外循环有效及安全的管理方法。方法2005年6月至2006年11月，对60～81岁的87例患者施行体外循环下的心脏手术。体外循环预充总量1500～2000mL，维持红细胞比容（Hct）24％～27％，晶胶比0．40～0．54。所有患者均使用中空纤维膜式氧合器，体外循环采用浅低温高流量灌注方法，4：1冷氧合血灌注进行心肌保护。术中监测血液稀释度、平均动脉压、血电解质及血糖等变化，定时进行血气分析，记录尿量。结幕体外循环时间38～190min，主动脉阻断时间20～105min，自动复跳66例（80％），术中灌注压60～80mmHg，尿量400～1800mL。全组87例中78例顺利脱离体外循环，5例经过辅助循环顺利脱机，4例置入主动脉内气囊反搏后顺利停机。术后出现并发症12例，包括神经系统并发症、肺部感染、消化道出血。1例患者死于感染后多器官衰竭。结论充分的术前准备，优质的膜式氧合器，合理的血液稀释度，有效的组织灌注以及良好的保护等综合性措施，有利于提高老年患者心脏病手术中体外循环的质量，并确保手术安全。

Objective To investigate the effective and safe way for management of cardiopulmonary bypass （CPB） in elderly patients. Methods From June 2005 to November 2006, eighty-seven patients aged from 60 to 81 years who underwent cardiac operation with CPB were included in the study. The prepared total volume of CPB was 1 500 -2 000 mL, the haematocrit（Hct） was maintained at 24% - 27% and the ratio of crystal to colloid at 0.40 -0.54. Hollow-fiber membrane oxygenators were applied to all the patients, superficial low temperature-high flow perfusion was employed, and 4：1 cold oxygenation blood perfusion was performed for myocardial preservation. The degree of hemodilution, mean arterial pressure, electrolyte and blood glucose were monitored during the operation, the arterial blood gas analysis was conducted at intervals, and the urine volume was recorded. Results The duration of CPB ranged from 38 to 190 min, and aorta cross-clamp（ACC） from 20 to 105 min. The heart rebeat automatically at the end of ACC in 66 cases （80%）. During the operation, the perfusion pressure was 60 to 80 mmHg, and the urine output was 400 to 1 800 mL. Seventy-eight cases were weaned from CPB successfully, 5 needed assisted circulation, and 4 were implanted intra-aortic balloon pump （IABP）. Postoperative complications were found in 12 cases, including nervous system complications, lung infection and gastrointestinal hemorrhage. One case died of multiple organ system dysfunction after infection. Conclusion Sufficient preoperative preparation, high-quality membrane oxygenator, reasonable hemodilution, effective tissue perfusion, myocardial protection and other comprehensive measures may help to improve and secure CPB in the cardiac operation in elderly patients.