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

BACKGROUND: 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.

STUDY DESIGN: Randomized double-blind controlled trial.

SETTING & PARTICIPANTS: 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.

INTERVENTION: 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.

OUTCOMES & MEASUREMENTS: 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).

RESULTS: 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).

LIMITATIONS: The trial did not follow up participants to assess need for dialysis and mortality rate.

CONCLUSION: The combination therapy of sodium bicarbonate plus saline does not offer additional benefits over hydration with saline alone in the prevention of CIN.