Sodium Bicarbonate Infusion: To Prevent Cardiac Surgery-Associated Acute Kidney Injury

OBJECTIVES: The incidence of cardiac surgery-associated acute kidney injury is 50% of patients and is associated with increased mortality and morbidity. This study aimed to determine if perioperative urinary and plasma alkalization with sodium bicarbonate infusion reduces the incidence of cardiac surgery-associated acute kidney injury. SETTING AND DESIGN: This study is double blind randomized control trial conducted at U N Mehta Institute of Cardiology and Research Center, India. METHODS AND RESULT: A total of 140 patients scheduled to undergo elective cardiac surgery, who were at increased risk of development of cardiac surgery-associated acute kidney injury using recognized risk factors. Patients were randomly allocated to receive either sodium bicarbonate (n = 70) or sodium chloride (n = 70) infusion, commencing at the start of anesthesia, in a dose of 4 mmol/kg over 24 hour. The primary outcome measure was the number of patients with development of CSA-AKI, defined as an increase in creatinine greater than 25% from baseline to peak value within the first three postoperative days. Significant differences among the groups in both plasma and urinary pH were achieved 6 hours after commencement of the infusion, and these changes persisted for more than 24 hours. A total of 7 out of 70(10%) patients in the sodium bicarbonate group and 16 out of 70(22.85%) patients in the sodium chloride group developed acute kidney injury within the first three postoperative days with p value of 0.06 which is statistically not significant. There were also no significant differences in ventilation hours, ICU or hospital length of stay, or mortality. CONCLUSIONS: Perioperative alkalization of blood and urine using an infusion of sodium bicarbonate did not result in a decrease in the incidence of acute kidney injury in patients undergoing cardiac surgery.