Background: A prospective observational study was carried out in a Cardiosurgical Intensive Care Unit (ICU) in order to evaluate the incidence of Acute Renal Failure (ARF) after coronary artery bypass graft surgery and identify its predictors. The effects of ARF on outcome were also investigated.
Methods: The study enrolled 3,013 consecutive patients undergoing coronary artery bypass graft surgery. Baseline variables including age, sex, preoperative renal failure, left-ventricular dysfunction, emergency surgery, neurological adverse events, patient history of chronic obstructive pulmonary disease and diabetes mellitus were collected. Intraoperative variables were: type of surgery (on- or off-pump), intra-aortic balloon pump placement, and cardiopulmonary bypass duration. The measured postoperative variables were: low cardiac output syndrome, hemorrhage, transfusion of blood products, and surgical revision.
Results: Preoperative renal dysfunction (creatinine >1.4 mg/dL), blood transfusion, low-output syndrome, emergency surgery, low ejection fraction and age were independently associated with ARF. The median (interquartile range) ICU stay was 5.5 (range 4-11.5) days in patients who did and 1 (range 1-2) day in those who did not develop ARF (P<0.001). The median (interquartile range) hospital length of stay was 10 (range 8-21) days in patients who did and 5 (range 4-7) days in those who did not develop ARF (P<0.001).
Conclusion: Preoperative renal dysfunction, blood transfusion, low-output syndrome, emergency surgery, low ejection fraction and age were independently associated with ARF. Length of ICU and hospital stay were reduced in patients not developing ARF.