A study in the American Journal of Roentgenology that looked at the effects of warming a low-osmolality CT contrast medium, iohexol 350, before injection found that “[t]he data suggest that maintaining iohexol 350 at room temperature is non-inferior to warming the agent to body temperature before injection.” The study looked at extravasation and patient reaction rates in two groups: patients who were injected with pre-warmed iohexol 350 (3,939) and those who were injected with room temperature iohexol (3.933).

Although ‘[e]extrinsic warming of iodinated CT contrast media to body temperature reduces viscosity and injection pressures,” incidences of extravasation and allergic/allergic-like reaction rates were similar. “The two groups were not different in terms of overall reaction rate (p=.19), extravasation rate (p=.69), allergic/allergic-like reaction rate (p=.06), or physiologic reaction rate (p>.99). Logistic regression adjusting for patient and CT characteristics (age, sex, conventional CT vs CTA, contrast media volume, injection location, needle gauge) showed no significant association of patient group and adverse reaction rate (odds ratio=2.19, 95% CI 0.68-7.00). Multivariable regression modeling demonstrated an excess of 0.27 adverse events per 100 patients within the room temperature group, below a 0.6% non-inferiority margin.”

Lead author Noor Basharat, BS, of the Department of Radiology, Valleywise Health Medical Center,  Phoenix, AZ, and his team concluded “The resources involved to prewarm iohexol 350 before injection may not be warranted.”

Source:

Noor F. Basharat, Karthik Ranganathan, Paul T. Kang, Daniel G. Gridley, and Albert T. Roh. Effect of Extrinsic Warming of Low-Osmolality CT Contrast Media (Iohexol 350) on Extravasations and Patient Reaction Rates: A Retrospective Study American Journal of Roentgenology Available online at https://www.ajronline.org/doi/abs/10.2214/AJR.21.26256. Accessed: August 19. 2021.