目的 研究Standford A 型急性主动脉夹层患者术后低氧血症相关危险因素。方法 回顾性分析内蒙古医科大学附属医院心脏大血管外科2012年3月至2017年7月行孙氏手术的64例Standford A 型急性主动脉夹层患者的临床资料。依据患者术后PaO2/FiO2值将患者分为低氧血症组(PaO2/FiO2＜200mmHg）与非低氧血症组（PaO2/FiO2≥200mmHg）两组。分析两组患者术前、术中及术后相关数据，采用Logistic回归分析Standford A 型急性主动脉夹层患者术后低氧血症的独立危险因素。结果 Standford A 型急性主动脉夹层患者术后低氧血症发生率为68.8%（44/64）。低氧血症组与非低氧血症组两组患者死亡率无明显差异（6.8% vs 1.5%,P=1.000）。低氧血症组中体重指数>24Kg/m2比率比非低氧血症组高（P＜0.05），非低氧血症组男性比率比低氧血症组高（P＜0.05）。低氧血症组患者术后机械辅助通气时间和重症监护室停留时间比非低氧血症组时间长（P＜0.05）。Logistic回归分析结果是：术前PaO2/FiO2≤300mmHg（OR=8.909，P=0.012）和术前白细胞计数＞10×109/L（OR=5.098，P=0.034）是术后发生低氧血症的独立危险因素。结论 术前PaO2/FiO2≤300mmHg、术前白细胞计数＞10×109/L是Standford A 型急性主动脉夹层术后发生低氧血症的独立危险因素。

To identify the risk factors associated to postoperative hypoxemia after surgery of Standford A acute aortic dissection. Methods This was a retrospective study of patients treated between September 2012 and July 2017 at the Department of Cardiac macrovascular Surgery, Affiliated Hospital of Inner Mongolia Medical University, China. Analyses were performed on the clinical data of 64 patients with Standford A acute aortic dissection who underwent Sun’s operation. According to whether they had postoperative hypoxemia, all the patients with Standford A aortic dissection were divided into two research groups，one is hypoxemia group (PaO2/FiO2＜200mmHg，another is non-hypoxemia group （PaO2/FiO2≥200mmHg）. Clinical data relative to perioperative were analyzed between hypoxemia group and non-hypoxemia group. Logistic regression was performed to insure some possible relative risk factors of postoperative hypoxemia after surgery for Standford A acute aortic dissection. Results Incidence of postoperative hypoxemia after surgery for Standford A acute aortic dissection was 73%（44/64）. There was no difference between hypoxemia group and non-hypoxemia group in death（6.8% vs 1.5% , P=1.000）. The percentage of Body mass index ＞24Kg/m2 was high in hypoxemia group. The percentage of male was high in non-hypoxemia group than hypoxemia group（P＜0.05）. The duration of ventilation and lengths of intensive care unit and hospital stays were significantly longer in patients with hypoxemia. The difference in operative moratlity was not statistically between the hypoxaemia and non-hypoxaemia groups（6.8% vs 1.5%, P=1.000）. Logistic regression indentified that independent risk factors associated to postoperative hypoxemia after surgical repair of Standford A acute aortic dissection were preoperative PaO2/FiO2≤300mmHg（OR=8.909，P=0.012）and preoperative white blood cell count＞10×109/L（OR=5.098 , P=0.034）. Conclusions Preoperative PaO2/FiO2≤300mmHg and preoperative white blood cell count＞10×109/L were found to be the independent factors associated to postoperative hypoxemia after surgical repair of Standford A acute aortic dissection.