Sodium bicarbonate to prevent increases in serum creatinine after cardiac surgery: A pilot double-blind, randomized controlled trial

Objective: To test whether perioperative sodium bicarbonate infusion Can attenuate postoperative increases in serum creatinine in cardiac surgical patients, Design: Double-blind, randomized controlled trial. Setting: Operating rooms and intensive care unit at a tertiary hospital. Patients: Cohort of 100 cardiac surgical patients at increased risk of postoperative acute renal dysfunction. Intervention: Patients were randomized to either 24 hrs of intravenous infusion of sodium bicarbonate (41 mmol/kg) or sodium chloride (4 mmol/kg). Measurements and Main Results. The primary outcome measure was the proportion of patients developing acute renal dysfunction defined as a postoperative increase in plasma creatinine concentration >25% of baseline within the first five postoperative days. Secondary outcomes included changes in plasma creatinine, plasma urea, urinary neutrophil gelatinase-associated lipocalin, and urinary neutrophil gelatinase-associated lipocalin/urinary creatinine ratio. Patents were well balanced for baseline characteristics. Sodium bicarbonate infusion increased plasma bicarbonate concentration (p < 0.001), base excess (P < 0.001), plasma pH (p < 0.001), and urine pH (p < 0.001). Fewer patients in the sodium bicarbonate group (16 of 50) developed a postoperative increase in serum creatinine compared with control (26 of 50) (odds ratio 0.43 [95% confidence interval 0.19-0.98]), (p = 0.043). The increase in plasma creatinine, plasma urea, urinary neutrophil gelatinase-associated lipocalin, and urinary neutrophil gelatinase-associated lipocalin/urinary creatinine ratio was less in patients receiving sodium bicarbonate, (p = 0.014; p = 0.047; p = 0.009; p = 0.004). There were no significant side effects. Conclusions: Sodium bicarbonate loading and continuous infusion was associated with a lower incidence of acute renal dysfunction in cardiac surgical patients undergoing cardiopulmonary bypass. The findings of this pilot study justify further investigation. (Clinical Trials.gov, NCT00334191). (Crit Care Med 2009; 37:39-47)