Sodium bicarbonate for prevention of contrast-induced acute kidney injury: a systematic review and meta-analysis.

BACKGROUND: There have been conflicting reports on the use of intravenous administration of sodium bicarbonate for prevention of contrast-induced acute kidney injury (CI-AKI). The aim of this study was to evaluate the use of sodium bicarbonate for prevention of CI-AKI. METHODS: This is a symptomatic review and meta-analysis of prospectively randomized studies, abstracts and manuscripts, published from 1950 to 20 February 2009. RESULTS: Of 192 identified publications, 18 studies (n = 3055) were included. Nine studies were only published as an abstract. CI-AKI occurred in 11.6%. Six prospective studies demonstrated that intervention with sodium bicarbonate resulted in a decreased risk of CI-AKI. The aggregate result of the prospective trials also demonstrated a benefit favouring sodium bicarbonate (RR = 0.66, 95% CI = 0.45-0.95). This effect was most prominent in coronary procedures and in patients with chronic kidney disease. There was no effect on need for renal replacement therapy (RRT) and mortality. Published manuscripts demonstrated a beneficial effect, while abstracts could not. Also, funnel plot analysis suggested a publication bias. In addition, we found significant clinical and statistical heterogeneity between studies. Finally, the quality of the individual studies was limited. CONCLUSIONS: The incidence of CI-AKI was higher than recently reported, and varied among study cohorts. We found a preventive effect of the use of sodium bicarbonate on the risk for CI-AKI, however, with borderline statistical significance. There was no effect on need for RRT or mortality. The relative low quality of the individual studies, heterogeneity and possible publication bias means that only a limited recommendation can be made in favour of the use of sodium bicarbonate.