Subtle renal dysfunction after radiocontrast administration in prospective renal donors: Does N-acetylcysteine have a role in its prevention?

Abstract

<b>Background: </b> Radiographic contrast media (RCM) can cause a reduction in the renal function by multiple mechanisms; reactive oxygen species is one of them. Whether the reduction can be prevented by the administration of antioxidants is still debatable. <i> N</i> -acetylcysteine (NAC) has shown some benefit in patients with renal dysfunction in the prevention of radiocontrast-induced nephropathy (RCIN). <b> Materials and</b> <b> Methods</b> : We prospectively studied 95 healthy kidney donors, who were undergoing intravenous urography (IVU) followed by digital subtraction renal angiography (DSRA) with ionic, high-osmolar contrast agent for pretransplant evaluation. Patients were randomly assigned either to receive the <i> N</i> -acetylcysteine 600 mg orally twice daily (acetylcysteine group) or placebo (control group) on the day before and that of RCM administration in addition to the intravenous 0.45% saline (1 ml/kg body weight per hour) on the day and following day of the procedure. Serum creatinine, urinary enzymes <i> N</i>-acetyl β glucosaminidase (NAG), γ glutamyl-1-transferase (GGT), alanine amino peptidase (AAP), fractional excretion of sodium (FeNa) and 24-h urinary creatinine clearance were performed before and 48 h after the procedure. The levels of urinary enzymes measured after 96 h of DSRA were available in only 57 donors. Radiocontrast-induced nephropathy was defined as an increase in the baseline serum creatinine of at least 0.5 mg/dl within 48 h after injection of radiocontrast media (RCM). <b> Results: </b> Increase in the urinary enzymes (NAG, GGT and AAP) and reduction in creatinine clearance was observed in both groups after receiving the contrast media. However, the number of patients with significant increase in enzymuria (at least >50% increase above the baseline value) and mean drop in creatinine clearance was statistically not different between the acetylcysteine and control groups. <b> Conclusion:</b> Renal damage in the form of reduction in creatinine clearance and increase in urinary enzymes has been observed after administration of radiocontrast. However, clinically significant RCM-induced acute kidney injury is uncommon in patients with normal renal function. Prophylactic oral administration of the antioxidant <i> N</i> -acetylcysteine at a dose of 600 mg twice daily before and on the day of contrast administration is probably not required in patients with normal renal function.