急性Stanford A型主动脉夹层围术期低氧血症的临床分析

Analysis to the perioperative hypoxemia of acute Stanford type A aortic dissection

目的探讨急性Stanford A型主动脉夹层动脉瘤围术期低氧血症的预防及治疗。方法总结13例急性Stanford A型主动脉夹层动脉瘤患者围术期发生低氧血症的情况,其中男11例,女2例,年龄42.5±10.4岁,术前氧合指数（PaO2/FiO2）降低（≤300）者5例。在深低温停循环下完成涉及部分或全主动脉弓部替换手术12例,单纯Bentall术1例,体外循环时间265.9±62.6min,停循环时间40.3±20.9min。结果术后8例（61.5%）患者并发低氧血症,氧合指数为76~172（132.6±34.8）,经机械通气治疗,7例低氧血症得以纠治,顺利脱离呼吸机。术后低氧血症患者的肺动脉收缩压与主动脉收缩压之比手术前后差异无显著性（P〉0.05）。对比术后并发低氧血症与无低氧血症两组患者体重指数、体外循环时间、术中输血量、术后机械通气时间及术后住院天数,差异有显著性（P〈0.05）;而停循环时间差异无显著性（P〉0.05）。术前氧合指数降低患者组与正常患者组术后氧合指数差异有显著性（P〈0.05）。结论低氧血症是急性Stanford A型主动脉夹层围术期的常见并发症,充分重视危险因素并积极防治后多可纠正,预后良好。

Objective To explore the effective treatments for preventing and treating the perioperative hypoxemia of acute Stanford type A aortic dissection. Methods Of 13 patients, 11 males and 2 females in a mean age of 42.5±10.4 years, admitted from September 2004 to October 2007, with acute Stanford type A aortic dissection and perioperative hypoxemia, the data were retrospectively reviewed. All the patients had no history of lung disease. The preoperative oxygenation index of 5 patients decreased （PaO2/FiO2 ≤300）, seven patients were of obesity （body mass index ≥25）, and eight patients were undergone with emergency operation. A total or partial aortic arch replacement was performed in 12 patients under deep hypothermic circulatory arrest （DHCA）, and Bentall operation was performed in 1 case. The mean operative time in cardiopulmonary bypass was 265.9±62.6 minutes, and in DHCA was 40.3±20.9 minutes. Results Postoperative hypoxemia occurred in 8 patients （61.5%） and the oxygenation index （PaO2/FiO2） was 76-172 （mean 132.6±34.8）. Seven of the 8 patients were successfully cured after mechanical ventilation treatment and got out of breathing machine finally. There were no significant differences on mean operative time of DHCA and on the ratio of pulmonary artery systolic pressure to aortic systolic pressure before and after treatment （P〉0.05）. While the significant differences existed between postoperative hypoxemia group and non-hypoxemia group （P〈0.05） on body mass index （BMI）, mean operative time of cardiopulmonary bypass, blood transfusion volume within operation, time of postoperative mechanical ventilation and postoperative hospital days. There existed significant difference on the postoperative oxygenation index between the patients with preoperatively decreased oxygenation index and those with normal oxygenation index （P〈0.05）. Conclusions Hypoxemia is a common perioperative complication of acute type A aortic dissection caused by multiple factors. It may be reversed by enough attention to the risk factors and active prevention and treatment, especially mechanical ventilation.