Li Szu-Yuan, Chuang Chiao-Lin, Yang Wu-Chang, Lin Shing-Jong
Division of Nephrology, Taipei Veterans General Hospital, Taipei, Taiwan; Institution of Clinical Medicine, National Yang Ming University, Taipei, Taiwan.
Division of General Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institution of Clinical Medicine, National Yang Ming University, Taipei, Taiwan.
J Thorac Cardiovasc Surg. 2015 Mar;149(3):894-9. doi: 10.1016/j.jtcvs.2014.10.054. Epub 2014 Oct 14.
Acute kidney injury is a common and serious problem after cardiac surgery. Postoperative acute kidney injury is independently associated with in-hospital mortality and long-term morbidity, even after adjustment for comorbid diseases. Chronic kidney disease has been recognized as a strong risk factor of acute kidney injury after cardiac surgery. The association between proteinuria and postcardiotomy acute kidney injury in patients with preserved glomerular filtration rate remains uncertain.
Patients with an estimated glomerular filtration rate greater than 60 mL/min/1.73 m(2) who underwent cardiac surgery between January 2003 and December 2007 in a tertiary medical center were retrospectively analyzed. Dipstick urinalysis was performed before surgery. Proteinuria was categorized into negative, trace, 1+, 2+, or 3+. Postoperative acute kidney injury was defined by the Acute Kidney Injury Network criteria. Multinomial logistic regression was used to clarify whether proteinuria is an independent risk factor of postoperative acute kidney injury.
A total of 1246 patients were included in this study, with a mean estimated glomerular filtration rate of 80 ± 13 mL/min/1.73 m(2). Proteinuria was present in 290 patients (23.4%). Postoperative acute kidney injury developed in 434 patients (34.8%), and 36 patients (2.9%) required renal replacement therapy. Proteinuria was independently associated with all stages of postcardiotomy acute kidney injury and dialysis-requiring acute kidney injury. The crude risk of acute kidney injury was greater in patients with a higher grade of proteinuria. In subgroup analysis for gender, diabetes, and surgical type, preoperative proteinuria remains a strong risk factor of acute kidney injury after cardiac surgery.
Urine analysis is usually neglected before cardiac surgery despite the fact that proteinuria is the earliest manifestation of kidney dysfunction. In the current study, we show that urine protein is strongly and independently associated with postoperative acute kidney injury in subjects with preserved estimated glomerular filtration rate. These data suggest that such a relatively simple and clinically easy to use tool as a urinary dipstick may be useful to identify patients at high risk of acute kidney injury before cardiac surgery.
急性肾损伤是心脏手术后常见且严重的问题。术后急性肾损伤与院内死亡率及长期发病率独立相关，即便在对合并疾病进行校正之后亦是如此。慢性肾病已被公认为心脏手术后急性肾损伤的一个重要危险因素。肾小球滤过率正常的患者中蛋白尿与心脏手术后急性肾损伤之间的关联仍不明确。
对2003年1月至2007年12月在一家三级医疗中心接受心脏手术、估计肾小球滤过率大于60 mL/min/1.73 m²的患者进行回顾性分析。术前进行尿试纸条分析。蛋白尿分为阴性、微量、1+、2+或3+。术后急性肾损伤根据急性肾损伤网络标准定义。采用多项逻辑回归分析以阐明蛋白尿是否为术后急性肾损伤的独立危险因素。
本研究共纳入1246例患者，平均估计肾小球滤过率为80±13 mL/min/1.73 m²。290例患者（23.4%）存在蛋白尿。434例患者（34.8%）发生术后急性肾损伤，36例患者（2.9%）需要肾脏替代治疗。蛋白尿与心脏手术后急性肾损伤的所有阶段及需要透析的急性肾损伤独立相关。蛋白尿程度较高的患者急性肾损伤的原始风险更大。在按性别、糖尿病和手术类型进行的亚组分析中，术前蛋白尿仍是心脏手术后急性肾损伤的一个重要危险因素。
尽管蛋白尿是肾功能不全的最早表现，但心脏手术前尿液分析通常被忽视。在本研究中，我们表明，在估计肾小球滤过率正常的受试者中，尿蛋白与术后急性肾损伤密切且独立相关。这些数据表明，像尿试纸条这样相对简单且临床易于使用的工具可能有助于在心脏手术前识别急性肾损伤高危患者。
