第二军医大学  2014, Vol. 35 Issue (2): 136-140   PDF    
急性A型主动脉夹层术后肾衰竭的危险因素分析
王树伟1, 苏存华2, 阎岩1, 陆乘俊1, 韩林1, 徐志云1    
1. 第二军医大学长海医院胸心外科, 上海 200433;
2. 南京市第一医院心胸外科, 南京 210006
摘要目的 探讨急性A型主动脉夹层术后急性肾衰竭(acute renal failure,ARF)的危险因素。方法 回顾性分析2002年1月至2013年3月间接受手术的266例急性A型主动脉夹层患者资料,根据患者术后是否发生ARF分为ARF组和无ARF组,比较两组间一般临床特征间的差异,并采用多因素条件logistic回归方法分析术后ARF的独立危险因素。结果 18例(6.77%)患者术后发生ARF。两组患者在术前心功能不全(NYHA Ⅲ~Ⅳ级,P=0.024)、肾功能不全(P=0.002)、术中体外循环时间≥190 min(P=0.000)、主动脉阻断时间≥90 min(P=0.015)及术后二次开胸止血(P=0.004)、脑损伤(P=0.013)和急性呼吸功能障碍(P=0.000)的人数分布差异有统计学意义。ARF组患者的体外循环时间、主动脉阻断时间和围术期红细胞输注量高于无ARF组,差异有统计学意义(P均<0.05)。多因素条件logistic回归分析显示术前肾功能不全(OR=6.978,95% CI为1.874~25.997)、体外循环时间≥190 min(OR=5.663,95% CI为1.621~19.781)、围术期大量输注红细胞(OR=1.071,95% CI为1.030~1.113)和术后急性呼吸功能障碍(OR=4.853,95% CI为1.467~16.053)是术后ARF发生的独立危险因素。结论 ARF是多种因素共同作用导致的严重并发症。术后早期应严密观察患者病情变化,及时进行ARF评估并个体化干预,以减少住院死亡率并改善预后。
关键词胸主动脉     夹层动脉瘤     急性肾衰竭     危险因素    
Acute renal failure following operation in patients with acute type A aortic dissection:an analysis of risk factors
WANG Shu-wei1, SU Cun-hua2, YAN Yan1, LU Cheng-jun1, HAN Lin1, XU Zhi-yun1    
1. Department of Cardiothoracic Surgery, Changhai Hospital, Second Military Medical University, Shanghai 200433, China;
2. Department of Cardiothoracic Surgery, Nanjing First Hospital, Nanjing 210006, Jiangsu, China
Abstract: Objective To identify the risk factors of acute renal failure following operation in patients with acute type A aortic dissection (AAAD). Methods The clinical data of 266 consecutive patients undergoing operation for AAAD between Jan. 2002 and Mar. 2013 were retrospectively analyzed. The patients were divided into two groups according to the presence of postoperative acute renal failure. The general data were compared between the two groups. Univariate and multivariate conditional logistic regression analysis were used to determine the independent risk factors of postoperative acute renal failure. Results Eighteen (6.77%) patients had acute renal failure in our study. The incidence rates of preoperative cardiac dysfunction (NYHA Ⅲ-Ⅳ) (P=0.024), renal insufficiency (P=0.002), cardiopulmonary bypass time (CPBT)≥190 min (P=0.000), aortic cross-clamp time≥90 min (P=0.015), postoperative re-operation for bleeding (P=0.004), brain damage (P=0.013), acute respiratory dysfunction (P=0.000) and perioperative erythrocyte transfusions (P=0.015) were significantly different between the two groups preoperatively.Multivariate conditional logistic regression analysis showed that preoperative renal insufficiency (OR=6.978, 95% CI: 1.874-25.997), CPBT≥190 min (OR=5.663, 95% CI: 1.621-19.781), perioperative erythrocyte transfusions (OR=1.071, 95% CI: 1.030-1.113)and postoperative acute respiratory dysfunction (OR=4.853, 95% CI: 1.467-16.053)were independent risk factors for postoperative acute renal failure. Conclusion Renal failure is a severe complication caused by many risk factors after operation in AAAD patients. The patients should be monitored closely early after operation; the risks of acute renal failure should be assessed and individualized intervention should be given to improve hospital mortality and prognosis.
Key words: thoracic aorta     dissecting aneurysm     acute kidney failure     risk factors    

急性肾衰竭(acute renal failure, ARF)是心脏术后较为严重的并发症,肾功能损伤程度及治疗效果与患者预后密切相关[1]。患者一旦发生ARF,其病死率明显升高。急性A型主动脉夹层(acute type A aortic dissection,AAAD)是致死率较高的一种疾病[2],其手术风险高于一般心脏手术。因此,明确AAAD术后患者发生ARF的危险因素并加强围术期干预,对于减少肾功能损害、预防ARF的发生并改善术后早期和远期死亡率很重要。我们通过回顾性分析第二军医大学长海医院2002年1月至2013年3月266例AAAD患者的病例资料,探讨AAAD术后影响ARF发生的危险因素,以期为临床工作提供指导和帮助。

1 资料和方法
1.1 病例资料

选取第二军医大学长海医院胸心外科2002年1月至2013年3月手术治疗的AAAD患者资料,共266例,其中男性205例,女性61例,年龄18~77岁,中位年龄46.15岁,平均(46.21±11.73)岁。术前合并糖尿病11例(4.14%),高血压144例(54.14%),冠心病11例(4.14%),肾功能不全31例(11.65%),心功能不全(NYHA Ⅲ~Ⅳ级)110例(41.35%)。体外循环时间(cardiopulmonary bypass time,CPBT)172.32(145.01~197.74)min,术后二次开胸止血11例(4.14%)。

1.2 分组和相关定义

按照术后是否发生ARF记为ARF组和无ARF组。ARF的诊断参照 RIFLE分类标准[3],定义为术后血肌酐浓度在7 d内较术前上升≥3倍或肾小球滤过率下降75%以上,或者在术后血浆肌酐值≥352 μmol/L(40 mg/L)的基础上升高≥44 μmol/L(5 mg/L)。急性呼吸功能障碍是指患者在术后72 h内氧合功能障碍(PaO2/FiO2 < 150),并排除由于心源性肺水肿、感染所致肺炎、肺栓塞和血气胸所致呼吸功能障碍。术前肾功能不全是指术前检查中血肌酐和尿素氮水平高于正常值。住院死亡定义为术后住院期间死亡或经随访确定在转院后30 d内死亡。

1.3 统计学处理 采用SPSS

17.0软件进行统计分析。正态分布计量资料使用 ±s表示,非正态分布计量资料使用中位数和四分位间距表示,分别采用t检验或Mann-Whitney检验。计数资料以“例数(百分比)”表示,采用 χ2 检验或 Fisher 精确检验。取单因素分析中P<0.1的变量进行多因素条件 logistic回归方法分析术后ARF的危险因素。检验水准(α)为0.05。

2 结 果
2.1 患者一般临床特征

本组266例患者中,ARF组18例,无ARF组248例,除术前心功能不全(NYHA Ⅲ~Ⅳ级, P=0.024)、肾功能不全(P=0.002)外,年龄、性别、合并马凡综合征、糖尿病史、高血压史、吸烟史、冠心病史、心脏手术史在两组间差异无统计学意义(表 1)。

表1 各组患者的临床特征 Tab 1 Clinical data of enrolled patients
2.2 单因素分析

全组术后死亡26例(9.77%),ARF组7例(7/18,38.89%),无ARF组19例(19/248,7.66%),两组术后死亡率差异有统计学意义(P=0.001)。在CPBT≥190 min(P=0.000)、主动脉阻断时间≥90 min(P=0.015)及术后二次开胸止血(P=0.004)、脑损伤(P=0.013)、急性呼吸功能障碍(P=0.000)两组患者间的差异有统计学意义。此外,ARF组患者在体外循环时间、主动脉阻断时间及围术期红细胞输注量上高于无ARF组(P均<0.05)。具体见表 2。全组患者术后共发生急性呼吸功能障碍64例,其中死亡患者18例(18/64,28.13%),发生肾衰竭12例(12/64,18.75%)。术后未发生急性呼吸功能障碍202例,其中死亡8例(8/202,3.96%),发生肾衰竭6例(6/202,2.97%)。术后并发急性呼吸功能障碍患者的死亡率和肾衰竭发生率高于未并发急性呼吸功能障碍的患者(P均<0.001)。

表2 患者术中和术后相关指标单因素分析结果
Tab 2 Univariate analysis of intraoperative and postoperative indicators
2.3 多因素条件logistic回归分析 多因素条件logistic回归分析发现,AAAD术后发生ARF的独立危险因素为:术前肾功能不全(P=0.004,OR=6.978,95% CI为1.874~25.997)、CPBT≥190 min(P=0.007,OR=5.663,95% CI为1.621~19.781)、围术期大量输注红细胞(P=0.001,OR=1.071,95% CI为1.030~1.113)及术后急性呼吸功能障碍(P=0.010,OR=4.853,95% CI为1.467~16.053),详见表 3
表3 患者术后并发ARF的多因素logistic回归分析 Tab 3 Multivariate logistic regression analysis of factors for postoperative acute renal failure (ARF)

高龄是急性A型主动脉夹层患者术后死亡的重要危险因素,有研究发现年龄>70岁是术后ARF发生的独立危险因素[10]。这可能与高龄患者长期高血压等因素对肾脏损害增加、肾功能储备较差有关。本研究中年龄未成为术后ARF发生的危险因素,这可能与所选取发生ARF的患者年龄均<70岁有关,本组中年龄≥65岁的人数分布在ARF组和无ARF组间差异无统计学意义。

输血是心脏外科围手术期较为常见的治疗方式。Daly等[11]报道的输血率为57%;Andreasen等[12]报道的输血率为38%~64.2%。由于A型主动脉夹层修复手术范围较大,术中出血通常较多,为了提高红细胞浓度以增加组织供氧,外科医生倾向于选择输注异体红细胞以改善组织缺氧,因此术中和术后异体红细胞输注量较一般心脏手术高。但大量输注异体红细胞有危险性和不良后果[13]。本组研究结果也显示,围术期红细胞输注量在术后ARF组和无ARF组之间差异有统计学意义(P<0.05),是术后ARF的独立危险因素(P=0.001,OR=1.071,95% CI为1.030~1.113)。提示我们需要权衡输注异体红细胞的利弊,以减少术后ARF的发生。

本研究还发现术前肾功能不全(P=0.004,OR=6.978,95% CI为1.874~25.997)和CPBT≥190 min (P=0.007,OR=5.663,95% CI为1.621~19.781)均为术后发生ARF的独立危险因素。术前肾功能不全的患者由于肾脏存在不同程度的功能损害,且体外循环过程使得肾脏灌注方式发生显著改变,灌注量明显减少,肾脏连续处于低灌注状态,经受着不同程度的微循环缺氧。由于急性A型主动脉夹层手术的复杂性,患者术中通常需要更长时间的体外循环辅助时间,甚至处于深低温停循环的状态,当肾脏再灌注时,组织产生的超氧自由基及其产物对肾实质细胞产生进一步损害,最终导致术后肾衰竭。因此,对于伴有术前肾功能不全的患者我们应密切监测围术期肾功能变化,并早期积极进行相应的肾脏替代治疗。

急性呼吸功能障碍是A型主动脉夹层常见的术后并发症之一。研究发现,主动脉夹层的发生可导致全身炎症系统的活化,并可能进展成为系统性炎症反应综合征(systemic inflammatory response syndrome ,SIRS)[14,15]。疾病本身的炎症反应、术中体外循环和深低温停循环技术的使用均可导致肺内血管白细胞瘀滞和中性粒细胞的活化,并促进术后呼吸功能障碍的发生[16]。呼吸功能障碍所致血氧含量降低可进一步加重肾实质的缺氧和损害,最终导致术后肾衰竭。研究中我们发现,术后并发急性呼吸功能障碍患者的死亡率(18/64,28.13%)和肾衰竭发生率(12/64,18.75%)高于未并发急性呼吸功能障碍的患者(P均<0.001)。

综上所述,术前肾功能不全、CPBT≥190 min、围术期大量输注红细胞和术后急性呼吸功能障碍均为术后发生ARF的独立危险因素。提示我们术后早期严密观察患者病情变化,及时进行术后ARF的风险评估并个体化干预,是减少术后ARF、减少住院死亡率、改善预后的关键。

4 利益冲突

所有作者声明本文不涉及任何利益冲突。

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