The relationship between iodinated contrast material temperature and adverse reactions: A meta-analysis of 307,329 injections

The effect of iodinated contrast material (CM) temperature on injection pressures and viscosity has been well established. However, the effect of extrinsic warming of CM on allergic reactions and extravasations remains unclear. The purpose of this study is to compare the rates of allergic reactions and extravasations between warmed CM to room temperature CM.We conducted a comprehensive systematic search using PubMed, Embase, and Web of Science databases for all studies that assess the impact of warmed CM on adverse reactions. The primary outcomes of our study were allergic reaction and extravasation rates. We calculated weighted pooled odds ratios (OR) and 95% confidence intervals (CI) for all outcomes using the random-effects model. A P-value <0.05 was considered statistically significant. We conducted subgroup analyses based on the viscosity of the CM.A total of five studies, including 307,329 CM injections (86,676 at room temperature and 220,653 warmed to 37 °C), were included in the analysis. For high viscosity CM, pre-warming was associated with significantly lower allergic reaction rates (OR: 0.59, 95% CI: 0.49-0.72, P < 0.00001). There was no significant difference in rates of extravasation for high viscosity CM (OR: 0.53, 95% CI: 0.20-1.43, P = 0.21).Our meta-analysis suggests that warming CM to 37 °C is a safe and effective approach to reduce the risk of allergic reactions and physiologic reactions during injection of high-viscosity CM. However, there was no significant difference in extravasation rates between warmed and room temperature CM, regardless of viscosity.