In May 2018, Einstein Healthcare Network (Philadelphia, PA) was named a finalist for ECRI Institute's 12th Health Devices Achievement Award for its research into reducing IV contrast extravasations that occur during contrast-enhanced CT examinations. After observing lower extravasation rates for one type of procedure, in which a test bolus of saline was administered using a power injector instead of being injected by hand, the Einstein team theorized—and ultimately demonstrated—that power-injecting the test bolus during all other contrast-enhanced CT examinations would likewise reduce extravasation rates.

The Health Devices Achievement Award recognizes innovative and effective initiatives undertaken by member healthcare institutions to improve patient safety, reduce costs, or otherwise facilitate better strategic management of health technology. For details about the winning submission and other finalists, see The Health Devices Achievement Award: Recognizing Exceptional Health Technology Management.

ECRI Institute congratulates the project team members: Ryan K. Lee, MD, Jason Rodulfa, MD, and Terence Matalon, MD.

The Challenge

To assess whether injecting a test bolus of saline using a power injector, instead of injecting it by hand, can decrease the number of subsequent IV contrast extravasations that occur during contrast-enhanced CT examinations.

The Landscape

1. Extravasation of IV contrast during a CT scan is an occasional patient safety concern that can, in rare instances, lead to severe complications.

a) According to the American College of Radiology (ACR), the incidence of extravasation ranges from 0.1% to 0.9% of contrast-enhanced CT examinations (ACR 2017). To place those figures into perspective, that translates into 100 to 900 extravasations per year for a hospital network that performs 100,000 contrast-enhanced CT examinations annually.

b) In most instances, extravasated IV contrast causes only temporary pain and swelling. However, severe complications have been reported, such as compartment syndrome or brachial plexopathy resulting in long-term pain and impairment requiring surgery (Wang et al. 2007).

c) One large study of 58 radiology practices found that moderate injuries occurred in 4.7% of extravasation cases, and severe injuries occurred in 0.8% of cases (Dykes et al. 2015).

2. In addition to potential medical complications and inconvenience for the patient, these events also disrupt the workflow of the radiology department, with assessment and management of the patient required after the event.

3. Thus, radiology departments have a keen interest in minimizing the incidence of extravasation.

4. While examining extravasation rates during its monthly quality meetings, the team at Einstein Healthcare Network made a key observation: The manner in which a test injection was performed appeared to correlate with the rate of extravasations.

a) In the Einstein network, it was common practice during IV-contrast-enhanced CT examinations to inject a pre-contrast test bolus of normal saline by hand. If no extravasation was observed, the iodinated contrast would be injected using a power injector.

b) The one exception was for cardiac CT angiography (CTA) studies, in which the saline was power-injected for the test injection.

c) The team noted lower rates of contrast extravasation for cardiac CTA studies when compared with all other IV-contrast-enhanced studies.

d) Since the only procedural difference was the use of a power-injected test bolus for the cardiac CTA studies, the team hypothesized that power injection of the bolus more closely reproduced the force and pressure of the iodinated contrast injection; thus, it would provide a more reliable assessment of the viability of the IV injection prior to administration of IV iodinated contrast.

5. The team conducted a study to test its hypothesis that power injection of the saline test bolus could lead to a decrease in extravasations.
 

The Process

1. Researchers calculated the extravasation rates during IV-contrast-enhanced CT studies for two time periods—before and after an intervention in which a different test-injection method was used:

a) Baseline data was collected for the 30-month period leading up to the May 2016 start of the intervention. During this pre-intervention period, the saline test bolus was hand-injected for IV-contrast-enhanced studies, with the exception of cardiac CTA studies.

b) Post-intervention data was collected for the 15-month period from May 2016 through July 2017. During this period, a new protocol was used, in which the saline test bolus was power-injected for all IV-contrast-enhanced studies.

2. The new protocol proceeded as follows:

a) Before administering the IV iodinated contrast, the clinician would inject 30 cc of saline through an IV line at the same rate as would be used for the actual IV contrast injection.

b) The same dual-syringe CT power injection system was used to inject both the saline and the contrast in two separate boluses. One syringe injected the saline, and the other injected the contrast.

c) If the test injection of saline was successful, IV contrast was then administered, followed by a 20 cc saline flush using the same power injector.

d) If the injected saline extravasated, the IV site was not used and a new site of access was attempted.

3. Researchers performed a statistical evaluation of the differences in extravasation rates in the pre-intervention and post-intervention periods.
 

The Results

1. Pre-intervention: In the 30-month study period during which the preexisting protocol was used, 113 contrast extravasation events occurred during 21,383 contrast-enhanced CT examinations. This translates to 5.28 events per 1,000 CT exams, representing 0.528% of patients.

2. Post-intervention: In the 15-month study period during which a power injector was used, 32 contrast extravasation events occurred during 12,865 contrast-enhanced CT examinations. This translates to 2.49 events per 1,000 CT exams, representing 0.249% of patients.

3. The power-injected saline bolus intervention resulted in a statistically significant 54% reduction in extravasation rate compared to the baseline period (p = 0.00004) using the chi-square test.

4. To further improve their understanding of this patient safety issue, researchers collected additional data about the extravasations that occurred. This included determining the most common IV site to extravasate, the most common IV gauge to be involved, the most common study to result in contrast extravasation, the volume of contrast extravasated, and other factors.
 

Key Takeaways

1. The intervention significantly reduced extravasation rates, compared with the previous practice of hand-injecting the saline test bolus for most contrast examinations.

2. The Einstein team reasons that power-injecting the test bolus is more likely to identify peripheral lines that might extravasate because this method of injection more closely reproduces the rate and subsequent pressure that will be generated during the contrast injection.

3. Despite the clear improvement, the team noted that the extravasation rates did not drop to zero. The team offers two theories about why that might be so:

a) Because IV iodinated contrast has a higher viscosity than saline, the force necessary to inject the contrast is somewhat greater than that needed to inject saline at that same rate. This slightly higher pressure could result in some IV sites that tolerated the saline test injection ultimately failing when the higher-viscosity iodinated contrast is injected.

b) It's possible that the power-injected test injection could cause micro tears that weaken the vessel enough to result in extravasation when the IV contrast is subsequently injected.

4. Regardless, such effects are likely to be minor, given the overall decrease in extravasation rates.