Objective: The purpose of this article is to prospectively assess the frequency and type of IV injection site complications associated with high-flow power injection of nonionic contrast medium in MDCT.
Subjects and methods: Contrast-enhanced (300-370 mg iodine/mL) MDCT examinations with high flow rates (up to 8 mL/s) using automatic CT injectors were performed according to standardized MDCT protocols. The location, type, and size (16-24 gauge) of IV catheters and volumes, iodine concentration, and flow rates of contrast medium were documented. Patients were questioned about associated discomfort, IV catheter sites were checked, and adverse effects were recorded.
Results: Prospectively, 4,457 patients were studied. The injection rate ranged from 1-2.9 mL/s (group 1; n = 1,140) to 3-4.9 mL/s (group 2; n = 2,536) to 5-8 mL/s (group 3; n = 781); 1.2% of the patients experienced extravasations (n = 52). Contrast medium iodine concentration, flow rates, and volumes were not related to the frequency of extravasation. The extravasation rate was highest with 22-gauge IV catheters (2.2%; p < 0.05) independently of the anatomic location. For 20-gauge IV catheters, extravasation rates were significantly higher in the dorsum of the hand than in the antecubital fossa (1.8% vs 0.8%; p = 0.018). Extravasation rates were higher in older patients (≥ 50 vs < 50 years, 0.6% vs 1.4%; p = 0.019). Different iodine concentrations did not trigger significant differences in contrast material reactions (p = 0.782).
Conclusion: Automated IV contrast injection applying high flow rates (i.e., up to 8 mL/s) is performed without increased risk of extravasation. The overall extravasation rate was 1.2% and showed no correlation with iodine concentration, flow rates, or contrast material reactions. Performing high flow rates with low-diameter IV catheters (e.g., 22-gauge catheters) and a location of IV catheter in the hand is associated with a higher extravasation rate.