Sodium bicarbonate-ascorbic acid combination for prevention of contrast-induced nephropathy in chronic kidney disease patients undergoing catheterization

Background: Sodium bicarbonate and ascorbic acid have been proposed to prevent contrast-induced nephropathy (CIN). The present study evaluated the effect of their combined use on CIN incidence. Methods and Results: We prospectively enrolled 429 patients with chronic kidney disease (CKD: baseline estimated glomerular filtration rate <60 mL/min/1.73 m²) prior to elective coronary catheterization. CIN was defined as absolute (≥0.5 mg/dL) or relative (≥25%) increase in serum creatinine within 72 h. In the saline hydration (n=218) and combined sodium bicarbonate+ascorbic acid (n=211) groups, a total of 1,500–2,500 mL 0.9% saline was given before and after the procedure. In addition, the combination group received 20 mEq sodium bicarbonate and 3 g ascorbic acid i.v. before the procedure, followed by 2 g ascorbic acid after the procedure and a further 2 g after 12 h. There were no significant differences between the basic characteristics and contrast volume in the 2 groups. CIN occurred in 19 patients (8.7%) in the saline group, and in 6 patients (2.8%) in the combined treatment group (P=0.008). Conclusions: Combined sodium bicarbonate and ascorbic acid could prevent CIN following catheterization in CKD patients.