Transient acute kidney injury after major abdominal surgery increases chronic kidney disease risk and 1-year mortality

Purpose: We conducted a retrospective cohort study to determine incidences of transient and persistent acute kidney injury (AKI) after major abdominal surgery and their impacts on long-term outcome. Materials and methods: We enrolled 3751 patients undergoing major abdominal surgery. Postoperative AKI was classified as transient or persistent based on the return of serum creatinine to the non-AKI range within 7 days post-surgery. Primary outcome was mortality within 1 year. We used multivariable Cox proportional hazard regression analysis to assess independent associations between AKI type and mortality. Results: Most patients with AKI were classified as transient (84%). Compared to patients without AKI, both patients with transient and persistent AKI demonstrated elevated 1-year mortality rates [adjusted hazard ratio (95% confidence interval): 2.01 (1.34-2.93); P = 0.001, and 6.20 (3.00-11.43); P < 0.001, respectively] and greater risk of chronic kidney disease progression at 1 year [adjusted odds ratio (95% confidence interval): 3.87 (2.12-7.08) and 23.70 (9.64-5822), respectively: both P < 0.001]. Conclusions: Although most AKI cases after major abdominal surgery recover completely within 7 days, even these patients with transient AKI are at higher risk for 1-year mortality and chronic kidney disease progression compared to patients without AKI. (C) 2018 Elsevier Inc. An rights reserved.