In all cases the patient should be well hydrated. This is particularly important in patients with underlying renal disease or diabetes mellitus. In the past patients with sickle cell trait, sickle cell disease or paraproteinemias (i.e. multiple myeloma and similar processes) were felt to be at increased risk for renal dysfunction following contrast media injection. Their risk is not increased when they are adequately hydrated.

Patients with renal impairment may be at decreased risk for further renal injury by using acetylcysteine (Mucormyst) 600 mg p.o. x 2 doses the day prior to the contrast injection then 600 mg p.o immediately before the injection and 600 mg p.o. several hours following the injection of contrast.

NEJM Volume 343:180-184 July 20, 2000 Number 3

Prevention of Radiographic-Contrast-Agent–Induced Reductions in Renal Function by Acetylcysteine

Martin Tepel, M.D., Marcus van der Giet, M.D., Carola Schwarzfeld, Ulf Laufer, M.D., Dieter Liermann, M.D., and Walter Zidek, M.D.
 
ABSTRACT

Background Radiographic contrast agents can cause a reduction in renal function that may be due to reactive oxygen species. Whether the reduction can be prevented by the administration of antioxidants is unknown.

Methods We prospectively studied 83 patients with chronic renal insufficiency (mean [±SD] serum creatinine concentration, 2.4±1.3 mg per deciliter [216± 116 µmol per liter]) who were undergoing computed tomography with iopromide, a nonionic, low-osmolality contrast agent. Patients were randomly assigned either to receive the antioxidant acetylcysteine (600 mg orally twice daily) and 0.45 percent saline intravenously, before and after administration of the contrast agent, or to receive placebo and saline.

Results Ten of the 83 patients (12 percent) had an increase of at least 0.5 mg per deciliter (44 µmol per liter) in the serum creatinine concentration 48 hours after administration of the contrast agent: 1 of the 41 patients in the acetylcysteine group (2 percent) and 9 of the 42 patients in the control group (21 percent; P=0.01; relative risk, 0.1; 95 percent confidence interval, 0.02 to 0.9). In the acetylcysteine group, the mean serum creatinine concentration decreased significantly (P<0.001), from 2.5±1.3 to 2.1±1.3 mg per deciliter (220±118 to 186±112 µmol per liter) 48 hours after the administration of the contrast medium, whereas in the control group, the mean serum creatinine concentration increased nonsignificantly (P=0.18), from 2.4±1.3 to 2.6±1.5 mg per deciliter (212±114 to 226± 133 µmol per liter) (P<0.001 for the comparison between groups).

Conclusions Prophylactic oral administration of the antioxidant acetylcysteine, along with hydration, prevents the reduction in renal function induced by iopromide, a nonionic, low-osmolality contrast agent, in patients with chronic renal insufficiency.
 
Additional reference: Manual on Contrast Media, 4^th edition, ACR, 1998