Incidence and outcomes of contrast-induced nephropathy after computed tomography in patients with CKD: a quality improvement report.

Background: Although there has been considerable investigation of the general characteristics of contrast-induced nephropathy (CIN), it has not been studied adequately in a computed tomography (CT) population. We assessed the incidence and outcomes of CIN after contrast-enhanced CT in patients with chronic kidney disease pretreated with saline and N-acetylcysteine (NAC).

Design: Quality improvement report.

Setting & Participants: 520 patients registered in a CIN prevention program.

Quality Improvement Plan: We initiated the CIN prevention program in January 2007. In this program, patients with chronic kidney disease undergoing contrast-enhanced CT in an outpatient setting were automatically referred to nephrologists, and patients received saline and NAC before and after CT. The development of CIN was assessed 48-96 hours after CT.

Outcomes: Incidence of CIN and time to renal replacement therapy.

Measurements: Baseline serum creatinine, hemoglobin, and serum albumin levels; type and volume of contrast agents; and post-CT serum creatinine level.

Results: Overall, CIN occurred in 13 (2.5%) patients. Incidences of CIN were 0.0%, 2.9%, and 12.1% in patients with an estimated glomerular filtration rate of 45-59, 30-44, and <30 mL/min/1.73 m(2), respectively. The risk of CIN was increased in patients with severely decreased kidney function and diabetes. The development of CIN consequently increased the risk of renal replacement therapy (P < 0.001 by log-rank), and the risk was significantly accentuated in patients with estimated glomerular filtration rate <30 mL/min/1.73 m(2).

Limitations: A single-center study and comparison with previous studies.

Conclusions: The incidence of CIN was relatively low in patients treated with saline and NAC. The development of CIN predisposed to poor kidney survival in the long term.