Sodium bicarbonate for the prevention of contrast induced nephropathy: a meta-analysis of published clinical trials.

BACKGROUND: Contrast induced nephropathy (CIN) is a serious but rare complication following contrast based procedures. Sodium bicarbonate (NaHCO(3)) has been postulated to prevent CIN by various mechanisms. However, the outcomes following sodium bicarbonate administration to prevent CIN have been inconsistent. METHODS: A meta-analysis of published randomized clinical trials to determine if the administration of sodium bicarbonate is superior to sodium chloride among patients with chronic renal failure undergoing catheterization and interventional procedures in preventing CIN was performed. RESULTS: Data were combined across seven published clinical trials consisting of 1734 patients. There were no significant differences in the baseline characteristics between the NaHCO(3) and NaCl groups except patients in the bicarbonate group were heavier (P=0.04). The odds ratio (OR) for the development of contrast nephropathy for NaHCO(3) versus NaCl was 0.33 (95% confidence interval [CI] 0.16-0.69; P=0.003). Heterogeneity and publication bias were detectable with P-values 0.01 and 0.0005 respectively. There was no difference between the NaHCO(3) group and the NaCl group in the occurrence of death [OR 0.6; 95% CI (0.26-1.41); P=0.24], congestive heart failure [OR 0.85; 95% CI (0.32-2.24); P=0.74] and the requirement for renal replacement therapy [OR 0.56; 95% CI (0.22-1.41); P=0.22]. CONCLUSION: This meta-analysis demonstrates that based on currently available randomized trials, the administration of NaHCO(3) is superior to the administration of NaCl alone in the prevention of CIN among patients with moderate to severe chronic kidney disease. However, further controlled clinical trials are needed due to significant study heterogeneity and publication bias.