Acute kidney injury in the postoperative period of cardiac surgery

Abstract

Objective: To identify the occurrence of acute kidney injury (AKI) in the postoperative period of cardiac surgery. Methods: A prospective cohort study including 51 patients exposed to coronary artery bypass surgery, valve replacement, or combined surgery (bypass surgery and valve replacement) without history of kidney disease and kidney transplant, and who were followed from the preoperative period until 72 hours after surgery. Acute renal failure was defined as baseline creatinine increase of 0.3 mg/dL in 48 hours or less, or its increase from 1.5 to 1.9-fold, or a reduction in urine flow <0.5mL/kg/h for 6 hours. The Kidney Disease: Improving Global Outcomes (KDIGO) classification was used. Results: The KDIGO classification showed that 92.2% of patients had renal impairment. The urinary flow criterion of this classification alone showed that 31.4% of patients had renal dysfunction in stage of risk, 33.3% in stage of renal injury, and 21.6% in stage of renal failure. By the serum creatinine criterion, 27.5% were identified in the stage of risk, 3.9% in stage of injury and another 3.9% in stage of kidney failure. Conclusion: A high percentage of patients in the postoperative period of cardiac surgery (coronary artery bypass surgery and valve replacement) progressed to acute kidney injury.