Radiocontrast media can make renal...

Radiocontrast media can make renal excretory function by altering renal hemodynamics or at tubulotoxic effects. In high-risk patients, the incidence of acute renal failure induced at radiocontrast media is estimated to be 10 to 30 percent It is the third leading cause of acute renal failure in hospitalized patients, accounting for around 10 percent of cases. Although several strategies have been used to make less the incidence of contrast nephropathy, including diuretics, dopamine, calcium channel blocker atrial natriuretic peptides, aminophylline, and endothelin antagonists, and nothing else hydration has been accepted as a preventive strategy. Birck and colleagues examined the evidence for prevention of contrast nephropathy using acetylcysteine.

The authors performed a meta-analysis using electronic databases, intimation lists, and proceedings of major clinical meetings to identify relevant studies performed within the previous five years. Eligible studies were prospective, randomized controll trials including patients with chronic renal insufficiency who were receiving intravenous contrast media. The unfolding of acute renal failure was required to be a primary application of mind outcome measure. Two researchers independently assessed the eligibility and quality of each study

Thirteen respects were identified, of which seven were trials that used a combined total of 805 patients. Six studies involved intra-arterial contrast used for cardiovascular studies, and the same concerned intravenous contrast used during elective comput tomographic studies. All media were nonionic, and the mean amount of contrast given was 75 to 187 mL Oral acetylcysteine was given in different formulations and regimens, with the mostly common being 600 mg twice daily forward the day before and the day of the operation Overall, 403 patients were randomized to acetylcysteine plus intravenous hydration, and 402 were randomized to intravenous hydration alone. The mean age of patients was 69 years, and the proportion of men ranged from 57 to 90 percent and patients with diabetes from 21 to 64 percent

In four of the studies, acetylcysteine was associated with a significant reduction in the risk of contrast nephropathy.When data from all seven studies were combined, acetylcysteine plus hydration significantly reduc the relative risk of contrast nephropathy according to 56 percent when compared with hydration alone. There was no overall relationship between the amount of contrast media administered or the measure of chronic renal insufficiency before the procedure

The authors terminate that acetylcysteine is a safe and inexpensive prophylactic treatment for contrast nephropathy in high-risk patients. They call for studies to elucidate the optimal dosage regimens for this use.

Birck R et al. Acetylcysteine for prevention of contrast nephropathy: meta-analysis. Lancet August 23 2003; 362:598-603

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