Incidence and risk factors of postoperative acute renal injury in patients underwent hip and knee replacement

Abstract

Objective To investigate the incidence and risk factors of postoperative acute renal injury (AKI) in patients after primary unilateral hip and knee replacement. Methods Between January 2016 and July 2018, A total of 1 490 patients underwent hip and knee arthroplasty were enrolled. There were 507 male and 983 female with a median age of 66 years (range: 18 to 95 years). There were 201 patients underwent femoral head replacement, 897 total hip arthroplasty and 392 total knee arthroplasty, respectively. The creatinine value was 68.79 μmol/L preoperatively. Demographic, perioperative and postoperative data were recorded. The development of AKI was defined according to Kidney Disease Improving Global Outcomes (KDIGO) criteria. The demographic information, comorbidities, preoperative medication, type of surgery, type of anesthesia, intraoperative anesthetics, operation time, intravenous fluid type and dose, amount of bleeding and postoperative creatinine values were recorded. Predictors associated with AKI and postoperative creatinine was determined by multiple regressions. Results There were 80 cases developed AKI with the incidence of AKI 5.4%. Among the AKI patients, there were 69 cases (4.6%) in AKI stage 1, 7 cases (0.5%) in AKI stage 2, and 4 cases (0.3%) in AKI stage 3. The creatinine value was 72.03 μmol/L after surgery. The length of postoperative hospital stay was 9 days. There were 5 patients died in hospital. The independent risk factors of AKI after hip and knee arthroplasty included old age, a higher American Society of Anesthesiologists (ASA) grade and preoperative diabetes (P<0.05). The risk of postoperative AKI in patients aged 60-69 years, 70-79 years, and older than 80 years was 2.259, 2.798, and 6.049 times than that of patients under 60 years of age, respectively. The risk of postoperative AKI in patients with ASA grade II, III, and IV was 3.749, 9.023, and 21.595 times than that of ASA grade I patients, respectively. The risk of AKI in patients with diabetes before surgery was 2.377 times higher than that in non-diabetics. Age, diabetes, hypertension and preoperative serum creatinine were positively correlated with postoperative creatinine values (P<0.05). Intensive care unit admissions were greater in AKI patients than that in non-AKI patients (25.0%, 5.6%, χ2=-6.774, P<0.001). Compared with non-AKI patients, the postoperative length of hospital stay was longer in AKI patients (Z=-3.904, P<0.001). Conclusion The incidence of postoperative AKI after primary hip and knee replacement was 5.4%. The older age, ASA grade, and diabetes were independently associated with risk of AKI. Old age, male, preoperative diabetes, hypertension and a higher preoperative creatinine value can predict postoperative increased creatinine levels at postoperation. The risk factors for AKI included old age, a higher ASA grade and diabetes. The postoperative length of hospital stay was longer in AKI patients. Key words: Acute kidney injury; Risk factors; Arthroplasty, replacement, hip; Arthroplasty, replacement, knee