Contrast-induced anaphylaxis: does it occur in the medical environment and is it being responded to appropriately?

To analyze the appropriateness of primary response for anaphylaxis due to iodinated contrast media (ICM) or gadolinium-based contrast agents (GBCA).

This retrospective study included all patients in whom intravenous contrast agents (five types of ICMs and four types of GBCAs) were administered at our hospital between April 2016 and September 2021. For the patients who developed anaphylaxis, we obtained data on the time records of contrast injection, anaphylaxis onset, and intramuscular adrenaline (epinephrine) administration.

Of the 76,555 ICM and 30,731 GBCA administrations, anaphylaxis occurred in 49 cases (0.05%), and in 48 cases (98.0%) the onset was within 30 min after administration with widely distributed times (median, 7.5 min; interquartile range, 4.5-10.8 min; max, 26 min). Intramuscular adrenaline administration was performed in 43 cases (87.8%), and this was done within five minutes after the onset in 37 cases (75.5%). Only in 24 cases (49.0%), there were time records of both the onset and adrenaline administration (if performed).

Anaphylaxis occurred within 30 min after contrast injection in the majority of the cases, but times were widely distributed. Only in 75.5% of cases, appropriate primary treatment was performed, and the importance of keeping exact time records in patients' charts should be re-emphasized.