Sodium bicarbonate therapy for prevention of contrast-induced nephropathy: a systematic review and meta-analysis.

Optimal hydration measures to prevent contrast-induced nephropathy are controversial. We conducted a systematic review and meta-analysis using the MEDLINE database (1966 to January 2008), EMBASE (January 2008), and abstracts from conference proceedings. Adult patients undergoing contrast procedures. Randomized controlled trials comparing intravenous hydration with sodium bicarbonate with hydration with intravenous normal saline for prevention of contrast-induced nephropathy. Hydration with intravenous sodium bicarbonate with or without N-acetylcysteine versus hydration with normal saline with or without N-acetylcysteine. Contrast-induced nephropathy, need for renal replacement therapy, and worsening of heart failure. Twelve trials (1,854 participants) were included. Sodium bicarbonate significantly decreased the risk of contrast-induced nephropathy (12 trials, 1,652 patients; odds ratio [OR], 0.46; 95% confidence interval [CI], 0.26 to 0.82; I2 = 55.9%) without a significant difference in need for renal replacement therapy (9 trials, 1,215 patients; OR, 0.50; 95% CI, 0.16 to 1.53; I2 = 0%), in-hospital mortality (11 trials, 1,640 patients; OR, 0.51; 95% CI, 0.15 to 1.69), or congestive heart failure compared with controls. Similar results were seen for the risk of contrast-induced nephropathy when sodium bicarbonate was compared with normal saline alone (OR, 0.39; 95% CI, 0.20 to 0.77), but not when sodium bicarbonate/N-acetylcysteine combination was compared with N-acetylcysteine/normal saline combination (OR, 0.68; 95% CI, 0.34 to 1.37). A subgroup analysis limited to published trials showed similar results (OR, 0.26; 95% CI, 0.10 to 0.64; I2 = 63.3%), whereas unpublished studies showed a nonsignificant decrease (OR, 0.85; 95% CI, 0.46 to 1.57; I2 = 25.9%) in risk of contrast-induced nephropathy. Publication bias and heterogeneity. Hydration with sodium bicarbonate decreases the incidence of contrast-induced nephropathy in comparison to hydration with normal saline without a significant difference in need for renal replacement therapy and in-hospital mortality. Larger studies analyzing patient-centered outcomes are needed.