Sodium bicarbonate infusion produced an increase in the pH of blood and urine, but did not decrease the risk for cardiac surgery-associated acute kidney injury in a subgroup of surgical patients at high risk for developing the postoperative complication.
Researchers enrolled 427 patients with preoperative or perioperative risk factors for the development of cardiac surgery-associated acute kidney injury (CSA-AKI). All were scheduled for cardiac surgery using cardiopulmonary bypass between February 2009 and June 2011. Two hundred fifth patients were randomly assigned sodium bicarbonate and 212 were assigned placebo, commencing at the start of anesthesia in a cose of 0.5 mEq/kg/hour for the first hour and then 0.2 mEq/kg/hour for 23 hours. Results of the phase 2, late-breaking clinical trial were presented at the American Thoracic Society 2012 International Conference.
Forty-four percent of patients developed CSA-AKI, defined as an increase in creatinine of at least 25% from baseline to peak value within the first five postoperative days. Researchers found no significant difference in development of CSA-ASKI between the groups: It occurred in 45% of the sodium bicarbonate group vs. 44% of the placebo group.
There was also no significant difference in ventilation hours (sodium bicarbonate, 20.8 hours; placebo, 24.9 hours), ICU length of stay (sodium bicarbonate, 2.23 days; placebo, 2.28 days) or hospital length of stay (sodium bicarbonate, 13.4 days; placebo, 12.8 days). According to study results, 2.8% of patients died in the ICU, 3.3% in the sodium bicarbonate group and 2.4% in the placebo group. Ninety-day mortality was similar (3.7% vs. 2.8%, respectively).
“On [the] basis [of these results] we cannot recommend the use of perioperative infusions of sodium bicarbonate to reduce CSA-AKI in these patients and do not believe further investigation of this therapy is justified,” researchers wrote in the study abstract.
Disclosure: The researchers report no relevant financial disclosures.