The Incidence and Risk Factors of Acute Kidney Injury After Coronary Artery Bypass Graft Surgery

Abstract

Background: Acute Kidney Injury (AKI) is a prevalent and important complication of cardiac surgery, which is associated with significant morbidity and mortality. Identification of risk factors associated with AKI will help it's prevent. Objectives: The objective of the present investigation was to identify risk factors for acute kidney injury in patients who underwent coronary artery bypass graft (CABG) surgery at a tertiary care center for cardiovascular patients in Iran. Patients and Methods: From March 2014 to April 2015, 490 consecutive patients who underwent On-pump CABG at Rajaie cardiovascular medical and research center were assessed. Baseline variables and perioperative data were collected and their association with the development of AKI was evaluated. Results: Patients' mean age was of 67.9 (SD = 12.5) years. From these patients 353 (72%) were male and 137 (28%) were female. Six deaths (1.3%) occurred among patients. Thirteen patients (2%) had AKI. The baseline serum creatinine concentrations in patients with AKI were significantly higher than other patients (P = 0.04). Volume of transfused red blood cells and hemoglobin value were different, associated with AKI (P < 0.05), while systemic arterial oxygen saturation and pressure values were not associated with AKI (P > 0.05). Mean arterial pressure (MAP) was not different in patients with AKI (P = 0.85). The mean pump time in patients with AKI was significantly higher than the other patients (P = 0.02). Postoperative Left ventricle ejection fraction (LVEF) in patients who developed AKI was significantly reduced compared with patients without AKI (P = 0.01). The in-hospital mortality of patients who developed AKI was 7.69% compared with 1.04% among those who did not (P = 0. 01). Conclusions: Acute kidney injury is the important postoperative organ dysfunction in patients who underwent CABG and preoperative elevated serum creatinine concentration, cardiopulmonary bypass time > 120 minutes, intraoperative anemia and blood transfusion were serious risk factors associated with AKI.