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 (9.64-58.22), 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.