Extravasation (leaking) of intravenous (IV) contrast during a CT scan is not uncommon and can cause harm to patients, with rare instances of severe complications, and requires assessment of the patient with observation following the event, which inconveniences the patient and disrupts the workflow of the healthcare team. During monthly quality improvement meetings, a team studied recent events at their hospital and identified a trend of increased contrast extravasation. They decided to design a process to reduce these events. Data from these reports showed that the rates of contrast extravasation were lower when using a dual-head power injector, typically used for cardiac CTs, rather than the routine precontrast test bolus administered via hand injection. They reasoned that using power injection for the test bolus would more accurately reproduce the contrast injection than hand-injected test bolus, so as to more accurately identify patients and IVs at risk of contrast extravasation.
The team implemented a new protocol, which requires a power injected 30 cc saline bolus through the patient’s IV prior to administering the iodinated contrast. The saline bolus is injected at a rate of 0.5 cc/sec to 1 cc/sec faster than the rate required for the corresponding CT exam, due to the lower viscosity of saline versus iodinated contrast. If the test injection of saline is successful, IV contrast is then administered, followed by a 20 cc saline flush using the same power injector. The power-injected test bolus is actively observed by the CT technologist at the scanner gantry to look for signs of extravasation. If the saline extravasates, the IV site is not used, and a new site of access is attempted by the emergency department, inpatient team, or the CT technologist (in the case of outpatient exams). If contrast still extravasates despite a successful saline test bolus, the event is recorded by the performing CT technologist and postcontrast extravasation protocols are followed. Following the initiation of the protocol using the power-injected saline test bolus, there was a 54% reduction in extravasation rate over 15 months.
