TOPLINE

In patients with a documented iodinated contrast allergy, administering contrast-enhanced CT imaging within 4 hours of initiating intravenous (IV) corticosteroid and diphenhydramine premedication was not associated with a higher rate or severity of breakthrough contrast reactions than administering it later.

METHODOLOGY

• Researchers conducted a retrospective chart review across five emergency departments in New Jersey from January 2022 to December 2024 to determine whether guideline-recommended 4-hour accelerated IV premedication was associated with fewer and less severe reactions in patients with iodinated contrast allergy.
• They included 347 patients aged 21 years or older (median age, 63 years; 69% women) who received IV premedication before contrast-enhanced CT; 279 patients (80%) received contrast within 4 hours of starting premedication, and 68 (20%) received it after more than 4 hours.
• The primary outcome was the proportion of any contrast reaction (mild, moderate, or severe), assessed within 30 minutes of contrast administration.

TAKEAWAY

• Any contrast reaction occurred in 3% of patients who received contrast-enhanced CT within 4 hours of starting IV premedication, compared with 4% of patients who received it more than 4 hours after starting IV premedication (P = .52).
• Overall, a total of 11 reactions occurred: six were mild, five were moderate, and none were severe; dermatologic manifestations were the most common reaction type, and no deaths occurred in either group.
• The median order-to-start time (time between CT order placement and imaging initiation) was 205 minutes longer for patients who received CT more than 4 hours after starting premedication than for those who received CT within 4 hours.

IN PRACTICE

"Our findings suggest that the current ACR [American College of Radiology] Accelerated IV premedication recommendations may not provide a measurable clinical benefit in reducing contrast reactions," the authors wrote.

"Our results further support the hypothesis that even shorter premedication times could be feasible, thereby reducing operational delays, improving ED [emergency department] workflow, and decreasing length of stay while maintaining patient safety," they added.

SOURCE

Chirag N. Shah, MD, with Robert Wood Johnson Medical School in New Brunswick, New Jersey, was the corresponding author of the study, which was published online on August 24 in The American Journal of Emergency Medicine.

LIMITATIONS

The groups were imbalanced and fell short of the prespecified target of 193 patients per group. The study was also underpowered to detect rare, severe reactions. Moreover, the retrospective chart review may have been affected by documentation bias and by variability in clinicians' assessments of reaction severity.

DISCLOSURES

The study received no financial support, and the authors reported having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.