Effect of sodium bicarbonate infusion in off-pump coronary artery bypass grafting in patients with renal dysfunction

Background and Aims: Acute kidney injury (AKI) following cardiac surgery is a major complication resulting in increased morbidity, mortality and economic burden. This study was designed to determine the benefit of sodium bicarbonate (NaHCO₃) supplementation in patients with stable chronic kidney disease (CKD) undergoing off-pump coronary artery bypass grafting (OP-CABG). Material and Methods: We prospectively studied 60 non-dialysis CKD patients with glomerular filtration rate (GFR) ≤60 ml/min/1.73 m² requiring elective OP-CABG. They were randomly allocatted to one of the two groups. One group received NaHCO₃ infusion at 0.5 mmol/kg first hour followed by 0.2 mmol/kg/h till the end of surgery and the other group received 0.9% NaCl. A third group of 30 patients without renal dysfunction undergoing OP-CABG was included. The serum creatinine was estimated prior to surgery, immediately after surgery and on postoperative days 1, 2, 3 and 4. Results: Ten patients (33.3%) in NaCl and 6 (20%) patients each in NaHCO₃ and normal groups developed Stage-1 AKI. None of our study patient required renal replacement therapy and no mortality was observed in any of the groups during the perioperative and hospitalization period. Conclusion: Perioperative infusion of NaHCO₃ in OP-CABG reduced the incidence of Stage-1 AKI by about 40% when compared to NaCl. The incidence of Stage-I AKI in NaHCO₃ group was similar to that in patients with normal renal function undergoing OP-CABG. A larger group of patients may be required to suggest a significance of renal protective benefit of NaHCO₃ in patients undergoing OP-CABG.