Nine randomised controlled trials (RCTs) were included (n=2,043 patients). The authors stated that most trials were not blinded.
Sodium bicarbonate was associated with a statistically significant reduction in contrast induced nephropathy compared to normal saline, odds ratio 0.45 (95% confidence interval (CI0: 0.26 to 0.79). Statistically significant moderate heterogeneity was found (p=0.016, I2 57.3%). There was evidence of publication bias (p=0.012). After adjusting for presumed unpublished trials, there was no significant difference in the incidence of contrast induced nephropathy between sodium bicarbonate and normal saline, odds ratio 0.65 (95% CI: 0.36 to 1.20).
There was no significant difference between sodium bicarbonate and normal saline in rates of need for renal replacement therapy (eight RCTs; p=0.330) or in-hospital mortality (four RCTs; p=0.499).