Preoperative Low Serum Albumin Levels Increase the Requirement of Renal Replacement Therapy after Cardiac Surgery.

BACKGROUND: Acute kidney injury is a common complication of cardiac surgery that increases morbidity and mortality. The aim of the present study is to analyze the association of preoperative serum albumin levels with acute kidney injury and the requirement of renal replacement therapy after isolated coronary artery bypass graft surgery (CABG). METHODS: We retrospectively reviewed the prospectively collected data of 530 adult patients who underwent isolated CABG surgery with normal renal function. The perioperative clinical data of the patients included demographic data, laboratory data, length of stay, in-hospital complications and mortality. The patient population was divided into two groups: group I patients with preoperative serum albumin levels <3.5 mg/dL; and group II pateints with preoperative serum albumin levels ≥3.5 mg/dL. RESULTS: There were 413 patients in group I and 117 patients in group II. Postoperative acute kidney injury (AKI) occured in 33 patients (28.2%) in group I and in 79 patients (19.1%) in group II. Renal replacement therapy was required in 17 patients (3.2%) (8 patients from group I; 9 patients from group II; P = .018). 30-day mortality occurred in 18 patients (3.4%) (10 patients from group I; 8 patients from group II; P = .037). Fourteen of these patients required renal replacement therapy. Logistic regression analysis revealing the presence of lower serum albumin levels preoperatively was shown to be associated with increased incidence of postoperative AKI (OR: 1.661; 95% CI: 1.037-2.661; P = .035). Logistic regression analysis also revealed that DM (OR: 3.325; 95% CI: 2.162-5.114; P = .000) was another independent risk factor for AKI after isolated CABG. CONCLUSION: Low preoperative serum albumin levels result in severe acute kidney injury and increase the rate of renal replacement therapy and mortality after isolated CABG.