Frequency and factors affecting the development of acute kidney injury following open heart surgery

Abstract

Aim: Acute kidney injury after cardiac surgery (CSA-AKI) is one of the most common complications in adult patients and associated with high mortality and morbidity. We aimed to evaluate the factors affecting the development of postoperative acute kidney injury, and frequency of hemodialysis in patients with normal preoperative renal function tests, and those with high preoperative renal function tests but no need of dialysis. Methods: Patients who underwent elective coronary artery bypass, valve surgery, or both surgeries in the Department of Thoracic and Cardiovascular Surgery of the university hospital between January 2009 and December 2009 were retrospectively examined in this cohort study. Preoperative data such as age, gender, body mass index, previous cardiac surgery, history of unstable angina, myocardial infarction and cardiogenic shock, preoperative drug use, history of comorbid diseases, left ventricular ejection fraction (%), intraoperative data such as type of surgery, the total time of surgery and cross-clamping time, postoperative data such as length of hospital and intensive care stay, the requirement of revision surgery and hemodialysis and mortality rates were recorded retrospectively. Results: Advanced age, long surgery and cross-clamp times were risk factors for CSA-AKI (P=0.002, F=0.03, F=0.02). There was no difference between the groups in terms of previous cardiac surgery, gender, left ventricular ejection fraction, preoperative nephrotoxic drug use and surgery type (P=0.69, P=0.10, P=0.19, P=0.66, P=0.86). The length of hospital and intensive care stay of patients with acute renal failure was longer (P=0.001, P=0.001). The requirement of hemodialysis after surgery was 1.3%, and mortality rate was 2%. Conclusion: We think that thorough examination of the patients who are at risk for CSA-AKI during the preoperative period and planning the optimal treatment will aid in decreasing postoperative mortality and morbidity.