Use of N-acetylcysteine prior to cardiac catheterization to prevent acute renal injury in patients with stage III chronic kidney disease

Background: The role of N-acetylcysteine (NAC) to protect against contrast-induced nephropathy (CN) in patients with pre-existing renal insufficiency remains controversial despite several randomized controlled trials and meta-analyses. The potential reasons of inconsistency may be due to differences in definition, type and dose of contrast medium, imaging procedures, and the frequency of other potential causes of acute renal injury. Renal function before contrast administration is a major determinant of deterioration in function after administration. Methods: We conducted a retrospective review of patients with Stage III Chronic Kidney Disease (CKD) who underwent cardiac catheterization from January 2000 through January 2004 in our hospital. The incidence of CN was examined in patients pretreated and not pretreated with NAC. Results: From January 2000 to January 2004, 189 patients with Stage III CKD underwent cardiac catheterization. All patients received 0.45% or 0.9% saline hydration prior to catheterization. NAC was given prior to 83 catheterizations and not given prior to 57. Eleven of 57 patients (19.3%) not pretreated with NAC developed acute renal injury (ARI) while 6 of 83 who received NAC (7.2%) developed ARI (p<0.05). Nineteen patients underwent more than one cardiac catheterization, but there was no pattern to their potential for multiple episodes of ARI irrespective of prophylactic NAC administration. Conclusion: In our study NAC offered significant protection against ARI in patients with Stage III CKD. No overt risk factor for multiple episodes of ARI was observed, nor was the occurrence of ARI after first cardiac catheterization predictive of ARI after a subsequent catheterization.