Clinical characteristics of adverse reactions to nonionic low osmolality contrast media in patients transferred from the CT room to the emergency room

Nonionic low osmolality contrast media (LOCMs) are used universally in computed tomography (CT) imaging. Although adverse reactions due to nonionic LOCMs are a common cause of emergency room (ER) admissions, few studies have investigated these adverse reactions. In the present study, we evaluated the characteristics of patients who were transferred from the CT room to the ER due to adverse reactions to contrast media, and we determined the risk factors for severe adverse reactions. A single-center retrospective study was conducted over a 41-month period. Baseline and clinical characteristics were evaluated and analyzed according to moderate and severe severity. In particular, risk factors of severe reactions were determined using logistic regression analysis. In total, 70 patients were admitted to the ER with adverse reactions due to nonionic LOCMs. Of these, 33 developed a moderate reaction, and 37 developed a severe reaction. Compared with the moderate reaction group, the severe reaction group was older, had higher blood pressures, showed more symptoms indicating the cardiovascular and central nervous system, and developed faster reactions to LOCMs. According to the multivariate logistic regression analysis, the age of the patient and time to onset of reaction demonstrated a statistical relationship with severe adverse reactions. In the receiver operating characteristic analysis, the optimal cutoff values for age and time to onset were 60 years and 5 min. In conclusion, clinicians should be attentive to anaphylaxis due to nonionic LOCM, in particular, for elderly patients aged older than 60 years and a time to reaction onset of less than 5 min.