背景：术后急性肾损伤（acute kidney injury，AKI）在临床上并不少见，与术后不良预后相关，包括住院时间延长、ICU入住率增加、医疗花费增加，甚至会导致术后慢性肾功能不全（chronic kidney disease，CKD）以及术后死亡率的增加。术后AKI占所有院内获得性AKI的18%-47%，主要与合并症、手术类型、肾毒性药物、造影剂的使用等多种因素相关。临床工作中，美国麻醉医师学会（American Society of Anesthesiologists， ASA）Ⅰ或Ⅱ级患者，围术期常被临床医师忽视，但此类患者术后仍存在AKI的风险。因此了解此类患者术后AKI的发生和危险因素对于保证患者安全、提高医疗质量有着重要意义。

目的：通过比较ASAⅠ或Ⅱ级、行初次膝关节置换术（total knee arthroplasty，TKA）患者术后AKI的发生情况，探讨ASAⅠ或Ⅱ级患者初次行TKA术后AKI的危险因素。

方法：本研究为单中心、回顾性队列研究。回顾性分析 2014 年1月至2019 年12月在我院行初次TKA、年龄≥18岁、ASA为I 或II级的患者 2 623 例，其中男性患者 513 例，女性患者 2 110 例。通过查阅电子病历系统及手麻系统收集人口学信息、围术期资料和术后AKI 的发生情况。根据改善全球肾脏病预后组织标准（Kidney Disease Improving Global Outcomes, KDIGO），按术后 48 h 内是否发生 AKI 将患者分为两组: AKI 组和 非 AKI 组。采用二元 Logistic 回归分析 ASA I或II级患者行TKA术后 AKI 的独立危险因素。

结果：共有 51 例( 1. 9%) 患者发生术后 AKI。与非AKI组比较，AKI组患者年龄较大，ASA分级Ⅱ级患者比例、高血压比例及术前诊断为骨关节炎的比例明显升高（P＜0.05)。两组患者的体重质量指数（Body mass index，BMI）、术前肌酐值、术前血红蛋白水平及术前贫血的比例均无统计学差异。AKI组患者行同期双侧TKA的比例、围术期异体输血比例、术后2d内血肌酐最高值和术后Ⅱ、Ⅳ级并发症发生率明显升高（P＜0.05），术后2d内Hb最低值明显降低（P＜0.05）,手术时间、止血带使用时间和术后住院时间明显延长（P＜0.05）。两组患者麻醉方式和时间、手术类型及术中胶体液的使用比例差异无统计学意义。与非AKI组比较，AKI组术前钙离子通道阻滞剂、围术期联合应用两种抗生素比例明显升高（P＜0.05）。两组围术期ACEI/ARB、β受体阻滞剂、利尿剂、硝酸酯类、口服降糖药、胰岛素和非甾体抗炎药的使用比例差异均无统计学意义。二元 Logistic 回归分析显示，围术期输血( OR = 3. 979， 95%CI 2.243~7.056，P<0.001) 、手术时间延长( OR=1.007，95%CI 1.001~1.013，P=0.031) 和围术期联合应用抗生素( 万古霉素+头孢呋辛/克林霉素) ( OR=4.053，95%CI 1.350~12.165，P=0.013) 是术后AKI的独立危险因素。

结论：围术期输血、手术时间延长和复合应用抗生素( 万古霉素+头孢呋辛 / 克林霉素) 是 ASA I或II级患者TKA术后 AKI 的危险因素。

Background Postoperative acute kidney injury is not uncommon, and it is associated with poor prognosis of patients, including prolonged length of hospital stay, increased ICU admission rate, increased medical costs, and even increased postoperative mortality.  Postoperative Acute Kidney Injury accounts for 18%-47% of all hospital-acquired AKI, which is related to pre-exisiting chronic disease，surgery types, nephrotoxic drugs, use of contrast media and others. ASAⅠorⅡpatients is often ignored during the perioperative period, and such patients still have the risk of AKI . Understanding the occurrence and risk factors of postoperative AKI in such patients is of great significance for ensuring patient safety and improving medical quality.

Objective The aim of this study was to determine the incidence and risk factors of postoperative AKI in patients with ASA physical status I or II undergoing primary total knee arthroplasty.

Methods This study was a single-center, retrospective cohort study. A total of 2 623 patients, aged more than 18 years old, with ASA physical status I or II, undergoing primary total knee arthroplasty from January 2014 to December 2019 were included. Demographic characteristics and perioperative data were collected. AKI was diagnosed according to the criteria from KDIGO and the patients were divided into two groups: AKI group and non-AKI group. Independent risk factors of acute kidney injury were evaluated by binary logistic regression.

Results Forty-one patients (1.9%) developed acute kidney injury postoperatively. Compared with the non-AKI group, the patients in AKI group were older, and the proportion of patients with ASA gradeⅡ, hypertension and osteoarthritis was higher (P < 0.05). There was no statistical difference in BMI, preoperative creatinine, and preoperative Hb between the two groups. In AKI group, the proportion of bilateral TKA, perioperative allogeneic blood transfusion, the highest level of postoperative serum creatinine within 2 days, and the incidence of postoperative grade II and IV complications increased significantly (P < 0.05), while the lowest level of Hb decreased significantly within 2 days after operation (P < 0.05).The operation time, duration of tourniquet and postoperative length of stay were significantly prolonged in patients with AKI (P < 0.05). There was no significant difference between the two groups in anesthesia methods, time of anesthesia, operation type and intraoperative colloid administration. Compared with non-AKI group, the proportion of CCB drugs and combined antibiotics during perioperative period in AKI group was significantly higher (P < 0.05), and the proportion of cefuroxime alone during perioperative period was significantly lower (P < 0.05). There was no significant difference in the use of ACEI/ARB, β-blockers, diuretics, nitrates, oral hypoglycemic agents, insulin and NSAIDs between the two groups during perioperative period. Binary logistic regression showed perioperative transfusion ( OR = 3. 979，95% CI 2. 243-7. 056，P < 0. 001) ，the duration of operation ( OR = 1. 007，95% CI 1. 001-1. 013，P = 0. 031) and perioperative combined use of antibiotics ( vancomycin + cefuroxime/clindamycin) ( OR = 4. 053，95% CI 1. 350-12. 165，P = 0. 013) were independent predictive factors of acute kidney injury.

Conclusion  Perioperative transfusion，longer duration of operation，and combined use of antibiotics ( vancomycin + cefuroxime/clindamycin) were risk factors for postoperative AKI in patients with ASA physical status I or II.