Prediction of severe adverse reactions to ionic and nonionic contrast media in Japan: evaluation of pretesting. A report from the Japanese Committee on the Safety of Contrast Media.

Abstract

In a nationwide prospective study of adverse reactions to intravenous contrast media (CM), the Japanese Committee on the Safety of Contrast Media compared high-osmolar ionic CM with low-osmolar nonionic CM. A total of 337,647 cases were analyzed. The reliability of pretesting with an intravenous injection of a small amount of CM as a means of predicting severe or fatal reactions was also evaluated. The predictive values of the pretest were 1.2% for ionic and 0.0% for nonionic CM, and the sensitivity values were 3.7% and 0.0%, respectively. Such low values render this test meaningless for predicting which patients are at risk of a severe adverse reaction. A comparison of the incidence of severe adverse reactions between the nonpretested and pretested patients, as well as between the nonpretested and pretested patients with negative results, disclosed no statistically significant differences. Also, no beneficial effects of premedication in patients with a positive pretest were proved. The authors therefore conclude that pretesting with an intravenous injection of a small amount of CM is not useful in predicting severe reactions to ionic or nonionic CM.