Breakthrough adverse reactions to low-osmolar contrast media after steroidpremedication

OBJECTIVE. The purpose of this study was to review the nature of adverse re actions, or "breakthrough reactions," experienced by patients who received steroid premedication and low-osmolar contrast media. We compared the demog raphics of patients having these breakthrough reactions with those of patie nts who did not develop these reactions. MATERIALS AND METHODS. We retrospectively reviewed our radiology quality im provement database to identify patients with breakthrough reactions that oc curred from January 1, 1994, through October 1, 1999, and we reviewed their medical records. We compared these patients with a control cohort of patie nts who had a history of prior adverse reaction to contrast media but no br eakthrough reaction after administration of low-osmolar contrast media and premedication with corticosteroids. RESULTS. Over the 6-year period, 52 patients experienced 61 breakthrough re actions. The breakthrough reaction was mild in 76% of the patients. The bre akthrough reaction was similar to the patient's initial adverse reaction in 85% of the patients. A history of seafood allergy or hay fever was statist ically more likely to be identified in the breakthrough group than the cont rol group. CONCLUSION. Breakthrough reactions occur in a substantial number of patient s despite premedication with steroids and use of low-osmolar contrast agent s. Typically the breakthrough reaction is of similar severity to the patien t's initial reaction. Severe or life-threatening reactions are seen in 24% of patients.