The value of proteinuria in predicting acute kidney injury after cardiac surgery in elderly patients

Abstract

Objective To evaluate the value of proteinuria in predicting acute kidney injury(AKI)after cardiac surgery in elderly patients. Methods To retrospectively analyze the perioperative clinical data of elderly patients(age 60 or older)undergone cardiac surgery with cardiopulmonary bypass at Guangdong General Hospital from January 2005 to December 2010.Target patients were divided into two groups according to AKI defined by the KDIGO criteria.Data for those two groups were examined by single-factor analysis, and then logistic regression analysis was used to further determine independent factors of AKI after cardiac surgery. Results Among 848 elderly patients, AKI occurred in 524(61.8%)participants, including 39.2%(n=332)at AKI stage 1, 16.6%(n=141)at AKI stage 2, and 6.0%(n=51)at AKI stage 3.A total of 15.9% of patients(n=135)had preoperative proteinuria, including 12.4%(n=105)with mild proteinuria, and 3.5%(n=30)with heavy proteinuria.Logistic regression analysis showed that proteinuria was correlated with postoperative AKI.With the increase of proteinuria, the risk of AKI also increased, and the OR values of mild and severe proteinuria were 1.758(1.020-3.029)and 4.758(1.326-17.077), respectively. Conclusions Preoperative proteinuria may predict the occurrence of AKI after cardiac surgery in elderly patients.There is a gradual increase in the risk of AKI as proteinuria becomes more severe.Early institution of therapeutic interventions may be used in elderly patients with preoperative proteinuria undergoing cardiac surgery to attenuate the risk of AKI. Key words: Proteinuria; Cardiac surgery; Acute kidney injury