Contrast medium-induced nephropathy: strategies for prevention.

Contrast medium-induced nephropathy (CIN) is the third leading cause of acute renal failure in hospitalized patients. The exact mechanism by which contrast media induce renal failure is complex and not completely understood. Alteration in renal hemodynamics and direct toxicity to tubular cells have been proposed. The most important risk factor for development of CIN is preexisting renal insufficiency. Identification of patients with risk factors for development of CIN is essential, as measures for prevention of CIN can be instituted. Administration of fluids such as sodium chloride has been the traditional cornerstone of preventive therapy. Alkalization of tubular fluid with intravenous sodium bicarbonate has dramatically reduced the frequency of CIN in patients with baseline impaired renal function. Based on available evidence, use of sodium bicarbonate constitutes the most reliable and effective option. Prevention of CIN has also been achieved with periprocedural use of N-acetylcysteine, but not as consistently as with sodium bicarbonate. Although many studies evaluated different N-acetylcysteine dosages and routes of administration, the optimal regimen has yet to be determined. Combinations of these preventive therapies are just emerging and require further research.