The Canadian Association of Radiologists guidelines for the prevention of contrast-induced nephropathy: a critical appraisal.

The purpose of this study is to critically appraise the Canadian Association of Radiologists (CAR) guidelines on the prevention of contrast-induced nephropathy (CIN).The Appraisal of Guidelines Research and Evaluation (AGREE) tool is a questionnaire that consists of 23 key items organized in 6 domains (scope and purpose, stakeholder involvement, rigor of development, clarity and presentation, applicability, editorial independence). Four radiologists read the guidelines and completed the questionnaire independently. To assess the quality of the evidence, the articles listed in the bibliography were reviewed, and the following data were collected and tabulated: the type of contrast, the administration route, and the level of evidence (Centre for Evidence Based Medicine, University of Oxford).The highest score was for scope and purpose (92%), whereas the lowest scores were for rigor of development (50%) and applicability (40%). The score for the remaining domains were the following: stakeholder involvement (59%), clarity and presentation (69%), and editorial independence (63%). Although the bibliography of the CAR guidelines list 46 articles, only 33 were deemed pertinent to support the recommendations related to risk stratification or risk reduction of CIN. Only 3 articles dealt specifically with intravenous injection of iodinated contrast. Four articles dealt with ionic contrast, and, in 17 references, the contrast type was not specified. The best evidence (level 1) was in support of risk-reduction recommendations, but, in 8 of the 9 articles cited, the route of administration studied was exclusively intra-arterial.It would be appropriate to revisit the topic of CIN and formulate new guidelines. A formal systematic review of the literature should be undertaken and the data extraction should specifically address contrast type and route of administration, as well as the applicability of any recommendations.