N-acetylcysteine and sodium bicarbonate versus N-acetylcysteine and standard hydration for the prevention of radiocontrast-induced nephropathy following coronary angiography

BACKGROUND: Radiocontrast-induced nephropathy (RCIN) is thought to be caused by renal ischemia and direct toxic effects on renal tubular cells brought on by contrast media. The combination of N-acetylcysteine (NAC) and hydration fluids (NaCl 0.9% or 0.45%) has been shown to reduce these deleterious effects and is commonly given prior to coronary angiography. The use of bicarbonate as the hydration anion has been shown to confer additional RCIN protection compared with that of saline. However, limited data are available regarding whether sodium bicarbonate hydration, proven to be beneficial alone, can further improve outcomes when given with NAC. OBJECTIVE: To compare the incidence of RCIN in patients undergoing coronary angiography from January 2002 to December 2005. Data were collected through electronic chart reviews. RESULTS: Forty-seven patients received NAC and sodium bicarbonate for hydration and 49 received NAC and standard hydration. Baseline characteristics between the 2 groups were similar. All patients received at least one 600 mg oral dose of NAC before before angiography was performed. RCIN was defined as impairment of renal function occurring within 72 hours of administering contrast media, indicated by an absolute increase in the serum creatinine level of 0.5 mg/dL or more. A total of 12.2% of the patients receiving NAC and standard hydration developed RCIN, versus 14.9% of the patients in the NAC and sodium bicarbonate group (p = 0.713). CONCLUSIONS: The addition of sodium bicarbonate to NAC does not appear to confer additional protection against the development of RCIN. Prospective, randomized, placebo-controlled trials are warranted to definitely determine how this combination compares with NAC and standard hydration in preventing RCIN.