The Effect of Sodium Bicarbonate on Renal Injury in Patients Undergoing Major Surgery: Evidence Predominantly from Cardiac Surgery

Background Acute kidney injury (AKI) is a common postoperative complication with no established pharmacologic prevention. Sodium bicarbonate (NaHCO₃) has been studied extensively for its renoprotective potential, but evidence is conflicting. Its influence depends on the patient’s prior renal function and the type of renal injury. We performed an updated meta-analysis to evaluate the efficacy and safety of perioperative intravenous NaHCO₃ for preventing renal injury after major surgery. Methods We searched PubMed, Embase, Web of Science, and Cochrane Library for randomized controlled trials comparing perioperative NaHCO₃ with control in adult patients undergoing major surgery (9 cardiac surgery trials and 1 orthotopic liver transplantation trial). Primary outcome was AKI incidence; secondary outcomes included serum creatinine change at 48 h, need for renal replacement therapy (RRT), and all-cause mortality. Random-effects models were used. Results Ten randomized controlled trials involving 1,544 patients were included. Perioperative NaHCO₃ did not reduce AKI incidence compared with control therapy (RR = 1.02, 95% CI 0.86–1.21, P = 0.81) or improve 48-h serum creatinine change (MD = − 0.66 µmol/L, 95% CI − 15.53 to 14.21). No significant effects were observed on RRT requirement or all-cause mortality. Subgroup analyses showed no consistent effect modification by surgical type, timing, or infusion duration, although high-dose NaHCO₃ showed a borderline signal of potential harm. Conclusions Perioperative intravenous sodium bicarbonate was not associated with a reduction in AKI incidence. The confidence interval does not exclude a small benefit or harm. Routine use solely for AKI prophylaxis is not supported.