肺叶切除术中少尿与术后急性肾损伤的关系

目的: 探索术中尿量对术后急性肾损伤(acute kidney injury, AKI)的影响,以及术后AKI发生的独立危险因素。方法: 选择2017年7月至2019年6月于北京大学第一医院在全身麻醉下接受择期肺叶切除术的患者作为研究对象进行回顾性队列研究。将入组患者按照是否发生术后AKI分为AKI组和对照组。首先对围术期各变量进行单因素分析,探讨其与术后AKI的关系;其次,采用受试者工作特征曲线(receiver operating characteristic curve,ROC curve)分析术中尿量对术后AKI的预测价值,并以约登(Youden)指数为最大值时的上下4个界值[以0.1 mL/(kg·h)为间隔]为少尿界值,采用单因素分析探索各界值定义下的少尿与AKI发生风险的关系,并取OR值最大者为少尿界值;最后,将单因素分析中P<0.10的围术期各变量共同代入多因素Logistic回归模型,分析术后AKI的独立危险因素。结果: 共1 393名患者最终纳入研究,术后AKI发生率为2.2%。ROC曲线显示术中单位尿量用于预测术后AKI的曲线下面积为0.636(P=0.009), 约登指数为最大值时(约登指数0.234,敏感度48.4%,特异度75.0%)的少尿界值为0.785 mL/(kg·h)。进一步取0.7、0.8、0.9、1.0 mL/(kg·h)以及传统界值0.5 mL/(kg·h)为少尿界值分析少尿对术后AKI的影响。单因素分析显示,以小于0.8 mL/(kg·h)为少尿界值时,少尿患者发生AKI的风险增加最为显著(OR=2.774, 95%CI 1.357~5.671, P=0.004)。多因素回归分析显示术中尿量<0.8 mL/(kg·h)(OR=2.698,95%CI 1.260~5.778, P=0.011)是术后AKI发生的独立危险因素,另两个独立危险因素为术前血红蛋白≤120.0 g/L(OR=3.605, 95%CI 1.545~8.412, P=0.003)以及术前估计肾小球滤过率<30 mL/(min·1.73 m²)(OR=11.009, 95%CI 1.813~66.843, P=0.009)。 结论: 对于肺叶切除术,术中少尿是术后AKI发生的独立危险因素,且尿量<0.8 mL/(kg·h)是可能的筛选标准。

Impact of oliguria during lung surgery on postoperative acute kidney injury

Objective: To explore the influence of intraoperative urine volume on postoperative acute kidney injury (AKI) and the independent risk factors of AKI.Methods: This was a retrospective cohort study recruiting patients who received selective pulmonary resection under general anesthesia in Peking University First Hospital from July, 2017 to June, 2019. The patients were divided into the AKI group and the control group according to whether they developed postoperative AKI or not. Firstly, univariate analysis was used to analyze the relationship between perioperative variables and postoperative AKI. Secondly, receiver operating characteristic (ROC) curve was used to explore the predictive value of intraoperative urine output for postoperative AKI. The nearest four cutoff values [with the interval of 0.1 mL/(kg·h)] at maximum Youden index were used as cutoff values of oliguria. Then univariate analysis was used to explore the relationship between oliguria defined by these four cutoff values and the risk of AKI. And the cutoff value with maximum OR was chosen as the threshold of oliguria in this study. Lastly, the variables with P<0.10 in the univariate analysis were selected for inclusion in a multivariate Logistic model to analyze the independent predictors of postoperative AKI.Results: A total of 1 393 patients were enrolled in the study. The incidence of postoperative AKI was 2.2%. ROC curve analysis showed that the area under curve (AUC) of intraoperative urine volume used for predicting postoperative AKI was 0.636 (P=0.009), and the cutoff value of oliguria was 0.785 mL/(kg·h) when Youden index was maximum (Youden index =0.234, sensitivity =48.4%, specificity =75.0%). Furthermore, 0.7, 0.8, 0.9, 1.0 mL/(kg·h) and the traditional cutoff value of 0.5 mL/(kg·h) were used to analyze the influence of oliguria on postoperative AKI. Univariate analysis showed that, when 0.8 mL/(kg·h) was selected as the threshold of oliguria, the patients with oliguria had the most significantly increased risk of AKI (AKI group 48.4% vs. control group 25.3%, OR=2.774, 95%CI 1.357-5.671, P=0.004). Multivariate regression analysis showed that intraoperative urine output <0.8 mL/(kg·h) was one of the independent risk factors of postoperative AKI (OR=2.698,95%CI 1.260-5.778, P=0.011). The other two were preoperative hemoglobin ≤120.0 g/L (OR=3.605, 95%CI 1.545-8.412, P=0.003) and preoperative estimated glomerular filtration rate <30 mL/(min·1.73 m²) (OR=11.009, 95%CI 1.813-66.843, P=0.009). Conclusion: Oliguria is an independent risk fact or of postoperative AKI after pulmonary resection, and urine volume <0.8 mL/(kg·h) is a possible screening criterium.