Anemia-associated acute kidney injury after cardiac surgery with cardiopulmonary bypass

Objective To investigate the incidence and to evaluate the risk factors of acute kidney injury (AKI) following cardiac surgery with cardiopulmonary bypass (CPB) at general hospitals. Methods A retrospective cohort database study was conducted, involving 233 patients who were scheduled to heart valve surgery or coronary artery bypass grafting (CABG) with CPB technique. Logistic regression was used to screen out the risk factors of AKI after the surgery. Results The study population, with an average age of 57±12 years (age 21 to 83) were investigated, there were 54(23.2%) diabetes patients, 105 (45.1%) hypertension patients, 21 (9%) chronic kidney disease (CKD) patients, and 51 (21.9%) anemia patients. Overall incidence of AKI was 32.2%. The Analysis Result indicates that preoperative CKD, anemia, hypoalbuminemia, left ventricular ejection fraction, intraoperative aortic block time, minimum mean arterial pressure, perioperative infection, and application of vancomycin are risk factors associated with postoperative AKI. Multiariable Logistic regression suggests that basic CKD (OR=9.498, P=0.001), anemia (OR=3.150, P=0.021), the LVEF before surgery (OR=1.733, P=0.045), intraoperative aortic block time (OR=2.227, P=0.026), and white blood cell (OR=3.357, P=0.032) were the independent risk factors of AKI. Conclusions AKI is a common complication following cardiac surgery with CPB. The patients with preoperative renal insufficiency, anemia, long intraoperative aortic block time and higher perioperative white blood cell count are subjected to a higher incidence of AKI. Alleviating patients’ anemia and reducing artery block of extracorporeal circulation time therefore might be potential means to mitigate the risks of AKI after cardiac surgery.