A retrospective comparison of preoperative estimated glomerular filtration rate as a predictor of postoperative cardiac surgery associated acute kidney injury

Abstract

Background: Cardiac surgery-associated acute kidney injury (CSA-AKI) remains common with distressingly high mortality. Over time, risk scorings systems have been developed to predict it and preoperative low estimated glomerular filtration rate (eGFR) has been regarded as one of the predicting risk factors. Objectives: The present study is aimed at assessing the relation of different ranges of preoperative eGFR with an incidence of CSA-AKI defined by the AKI network (AKIN) criteria. Materials and Methods: Files of 134 patients with eGFR of >40 cc/min/1.73 m2 body surface area (BSA) who underwent cardiac surgeries on cardiopulmonary bypass were screened for data collection. Occurrences of CSA-AKI were evaluated as per the AKIN criteria over the course of 3 postoperative days. The relationships of different ranges of preoperative eGFR with CSA-AKI were analyzed by appropriate statistical tests using Instat software and P 100 cc/min/1.73 m2. The CSA-AKI trend with different eGFR was also statistically insignificant (P > 0.05). Conclusion: In patients with preoperative eGFR >40 cc/min/1.73 m2 BSA, a lower preoperative eGFR (40–60 cc/min/1.73 m2) does not predict higher incidence of CSA-AKI as defined by AKIN criteria as compared to higher preoperative eGFR (>100 cc/min/1.73 m2). Lower height is independently associated with higher incidence of CSA-AKI in such patients.

Keywords

• acute kidney injury
• cardiac surgery
• cardiopulmonary bypass
• renal function
• urine