IV contrast administration for CT: A survey of practices for the screening and prevention of contrast nephropathy

OBJECTIVE. No widely accepted practice guidelines exist for the screening and prevention of contrast nephropathy in patients receiving iodinated IV contrast agents for CT examinations. Issues include screening to identify at-risk patients, discriminatory levels of renal insufficiency beyond which IV contrast material is contraindicated, and the use of preventive measures. We surveyed radiologists to identify the current practice patterns and to determine those areas in which guidelines are most needed. MATERIALS AND METHODS. Surveys were e-mailed to 2,000 radiologists. The survey included questions on the issues just described and respondent demographics. RESULTS. The response rate was 21%. Serum creatinine is the most commonly used screening method: 92% of respondents for inpatient examinations and 66% for outpatient examinations. Only 2% use estimated creatinine clearance. The average threshold serum creatinine value used to determine that patients should not receive IV contrast material is 1.5 mg/dL in 35%,1.7 mg/dL in 27%, and 2.0 mg/dL in 31% (mean, 1.78 mg/dL). Diabetes slightly lowers the threshold creatinine (mean, 1.68 mg/dL). Fewer than 30% of respondents frequently administer IV contrast material to patients with a renal transplant or multiple myeloma. The most commonly used preventive measures include hydration (93%), reduction of contrast dose (77%), and administration of acetylcysteine (39%). Overall, no important differences were found among practice settings or level of specialization. CONCLUSION. A wide variation of practice patterns is apparent in the screening and prevention of contrast nephropathy. In some cases, these patterns conflict with recommendations from the literature. The results of this study identify opportunities for further research and areas in need of improved practice guidelines.