Sodium bicarbonate plus isotonic saline versus saline for prevention of contrast-induced nephropathy in patients undergoing coronary angiography: a randomized controlled trial.

There is controversy about the prophylactic measures proposed for the prevention of contrast-induced nephropathy (CIN). We aim to compare the efficacy of the combination of sodium bicarbonate and isotonic saline and that of isotonic saline alone in preventing CIN. Randomized double-blind controlled trial. 265 consecutive patients 18 years or older with a serum creatinine level of 1.5 mg/dL or greater undergoing elective coronary angiography from August 2007 to June 2008 in Tehran Heart Center, Tehran, Iran. Study participants were randomly assigned to receive either 75 mL of 8.4% sodium bicarbonate added to 1 L of isotonic saline (n = 135) or isotonic saline alone (n = 130) as a bolus of 3 mL/kg for 1 hour before contrast injection, followed by an infusion of 1 mL/kg/h for 6 hours after the procedure. The primary end point was an absolute (>or=0.5 mg/dL) or relative (>or=25%) increase in serum creatinine level 48 hours after the procedure (CIN). There were no significant differences between the bicarbonate and saline groups regarding baseline demographic and biochemical characteristics, including baseline serum creatinine level (1.63 +/- 0.32 [SD] versus 1.66 +/- 0.50 mg/dL), baseline glomerular filtration rate (46.4 +/- 12 versus 45.4 +/- 12 mL/min/1.73 m(2)), and baseline urine pH (5.42 +/- 0.6 versus 5.46 +/- 0.8). Nine patients (7.4%) receiving sodium bicarbonate developed CIN as opposed to 7 patients (5.9%) in the saline group, which was not statistically different (odds ratio, 1.26; 95% confidence interval, 0.45 to 3.50; P = 0.6). The trial did not follow up participants to assess need for dialysis and mortality rate. The combination therapy of sodium bicarbonate plus saline does not offer additional benefits over hydration with saline alone in the prevention of CIN.