Analysis of the risk factors of acute kidney injury after total hip or knee replacement surgery

Original article eISSN 2384-0293 Yeungnam Univ J Med 2021;38(2):136-141 https://doi.org/10.12701/yujm.2020.00542 Analysis of the risk factors of acute kidney injury after total hip or knee replacement surgery Yoo Jin Lee, Bong Soo Park, Sihyung Park, Jin Han Park, Il Hwan Kim, Junghae Ko, Yang Wook Kim Department of Internal Medicine, Inje University Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea Received: July 1, 2020 Revised: September 15, 2020 Accepted: September 16, 2020 Corresponding author: Yang Wook Kim, MD Department of Internal Medicine, Inje University Haeundae Paik Hospital, Inje University College of Medicine, 875 Haeun-daero, Haeundae-gu, Busan 48108, Korea Tel: +82-51-797-3324 Fax: +82-51-797-3282 E-mail: Background: Postoperative acute kidney injury (AKI), which increases the risk of postoperative morbidity and mortality, poses a major concern to surgeons. We conducted this study to analyze the risk factors associated with the occurrence of AKI after orthopedic surgery. Methods: This was a retrospective study that included 351 patients who underwent total hip or knee replacement surgery at Inje University Haeundae Paik Hospital between January 2012 and December 2016. Results: AKI occurred in 13 (3.7%) of the 351 patients. The patients’ preoperative estimated glomerular filtration rate (eGFR) was 66.66 ± 34.02 mL/min/1.73 m2 in the AKI group and 78.07 ± 21.23 mL/min/1.73 m2 in the non-AKI group. The hemoglobin levels were 11.21 ± 1.65 g/ dL in the AKI group and 12.39 ± 1.52 g/dL in the non-AKI group. Hemoglobin level was related to increased risk of AKI (odds ratio [OR], 0.13; 95% confidence interval [CI], 0.02–0.68; p=0.016). Administration of crystalloid or colloid fluid alone and the perioperative amount of fluid did not show any significant relationship with AKI. Further analysis of the changes in eGFR was performed using a cutoff value of 7.54. The changes in eGFR were significantly related to decreased risk of AKI (OR, 0.74; 95% CI, 0.61–0.89; p=0.002). Conclusion: Renal function should be monitored closely after orthopedic surgery if patients have chronic kidney disease and low hemoglobin level. Predicting the likelihood of AKI occurrence, early treatment of high-risk patients, and monitoring perioperative laboratory test results, including eGFR, will help improve patient prognosis. Keywords: Acute kidney injury; Orthopedic procedures; Postoperative complications; Risk factors Introduction Postoperative acute kidney injury (AKI), which increases the risk of postoperative morbidity and mortality, poses a major concern to surgeons [1,2]. Previous studies reported a 9.1% risk of AKI after elective or emergency orthopedic surgical procedures [3,4]. According to a study conducted in patients who underwent any type of inpatient operative procedure in the United States, hospital mortality showed a high correlation with postoperative AKI. In patients with AKI, the lengths of stays in the intensive care unit (6 days vs. 2 days) and hospital (12 days vs. 5 days) were longer and the risk-adjusted average cost of care was higher than those in patients without AKI (US dollar [USD] 42,600 vs. USD 26,700) [5]. Several perioperative risk factors are associated with the development of AKI. The major perioperative risk factors include underlying chronic kidney disease (CKD), diabetes, and congestive heart failure during cardiac surgery [6]. However, little is known about the occurrence of postoperative AKI after orthopedic surgery. Patients undergoing orthopedic surgery are expected to have Copyright © 2021 Yeungnam University College of Medicine This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 136 https://doi.org/10.12701/yujm.2020.00542 Yeungnam Univ J Med 2021;38(2):136-141 a high probability of renal dysfunction because of comorbidities, potential high volume of blood loss, and development of perioperative infection. Recently, the number of orthopedic surgeries being performed has been increasing [7] along with the aging of the Korean population [8], which leads to a high number of high-risk Korean patients. Thus, we conducted this study to analyze the risk factors associated with the occurrence of AKI after orthopedic surgery to provide ample information that will aid the effective management of patients, such as elderly patients who have undergone orthopedic surgery. Materials and methods 1. Patients This study was approved by the Institutional Review Board (IRB) of the Inje University Haeundae Paik Hospital (IRB No: 2020-08018). Written informed consent was obtained from the study subjects. This retrospective study included 351 patients who underwent total hip or knee replacement surgery in Inje University Haeundae Paik Hospital between January 2012 and December 2016. Age, sex, preoperative glomerular filtration rate (GFR), postoperative GFR, drugs used (nonsteroidal anti-inflammatory drugs, angiotensin-converting-enzyme inhibitors, and statins), number of prescribed drugs (total number of drugs prescribed and taken at the hospital before surgery), albumin level (g/dL), hemoglobin level (g/dL), pro-B-type natriuretic peptide level (pg/mL), ejection fraction, and perioperative amount of fluid (the total amount of fluid administered in 3 days, including the day before surgery), types of fluid administered during surgery, presence of diabetes and hypertension, and presence of CKD were assessed. 2. Definition AKI was defined as a postoperative creatinine level of ≥ 0.3 mg/dL [9], and CKD was defined as a GFR of < 60 mL/min/1.73 m2, calculated using the Chronic Kidney Disease Epidemiology Collaboration equation [10]. The postoperative estimated GFR (eGFR) was based on value obtained on the third day after surgery. The change in eGFR from baseline was indicated as ΔeGFR. 3. Statistical analyses The study data are presented as frequencies with percentages for categorical variables and means ± standard deviations for continuous variables. The effect of the independent variables on the response variables was analyzed using multivariate logistic regression, and the statistically significant variables were selected using a backward elimination method with a 0.05 alpha level. Differences in the characteristics of the study participants were compared https://doi.org/10.12701/yujm.2020.00542 across subgroups by using the chi-square or Fisher exact test for categorical variables and the independent t-test or Mann-Whitney U-test for continuous variables. The Shapiro-Wilk test was used to check if the data distribution was normal. Univariate and multivariate analyses were performed using logistic regression to identify prognostic factors that are independently related to AKI. A rece (...truncated)