Background: Sodium bicarbonate has been postulated to prevent contrast-induced acute kidney injury (CI-AKI) by various mechanisms, although the reports are conflicting.
Methods and results: We searched MEDLINE, EMBASE, and the Cochrane databases for randomized controlled trials that compared a sodium chloride with a sodium bicarbonate hydration regimen with regard to CI-AKI. Data across 19 clinical trials consisting of 3,609 patients were combined. Preprocedural hydration with sodium bicarbonate was associated with a significant decrease in the rate of CI-AKI (odds ratio [OR] 0.56; 95% confidence interval [CI] 0.36-0.86; P=0.008). Stratified analyses by the type of contrast medium suggested lower odds of CI-AKI with sodium bicarbonate in studies using low-osmolar contrast media (OR 0.40; 95% CI 0.23-0.71, P=0.002) compared with those using the iso-osmolar agents (OR 0.76; 95% CI 0.41-1.43; P=0.40). No significant difference in the rates of postprocedural death (OR 0.49; 95% CI 0.23-1.04; P=0.06) and the requirement for renal replacement therapy (OR 0.94; 95% CI 0.46-1.91; P=0.86) was observed. However, we found significant changes in serum bicarbonate and potassium levels after sodium bicarbonate infusion.
Conclusions: This updated meta-analysis demonstrates that sodium bicarbonate-based hydration is superior to sodium chloride in preventing CI-AKI of patients undergoing exposure to iodinated contrast media.