Peripheral intravenous power injection of iodinated contrast media: the impact of temperature on maximum injection pressures at different cannula sizes

Modern computed tomographic scanners and examination protocols often require high injection rates of iodinated contrast media (CM). The purpose of this study was to investigate the maximum injection pressures (MIPs) with different CM at different temperatures in the most common intravenous cannula (IVC) sizes. Three IVC sizes, 22, 20, and 18 gauge, were evaluated. All examinations were performed with a pressure-limited (300 psi) power injector. The MIPs of three different CM (Solutrast 300, Imeron 350, and Imeron 400) were measured at room temperature (20 degrees C) and at 37 degrees C using increasing flow rates (1-9 mL/s). The intactness of the IVCs was checked after injection. Heating the CM led to reductions in injection pressures (P < .001). Using constant flow rates, the difference in MIP between 20-gauge and 22-gauge IVCs was higher than that between 20-gauge and 18-gauge IVCs. By heating the CM, the manufacturer's suggested operating pressure limit was exceeded at higher flow rates, such as with an 18-gauge cannula at 8 mL/s instead of 6 mL/s using warmed iomeprol 400. Even with pressures of up to 159.7 psi, none of the IVCs ruptured. Heating of CM effectively reduces MIPs using power injection in common IVCs. Although the manufacturer's suggested MIP was exceeded at higher flow rates, safe CM injection seems to be possible even in small cannulas using power injection. The compilation of the obtained data is meant to serve as guidance for future decisions on parameters of the power injection of iodinated CM.