Power-Injector Extravasation During CTA Chest in a Patient With Obesity

1. Stop the injection and get the injector off the line. Confirm on the console that no further volume is being delivered.
2. Disconnect the tubing but leave the cannula in place briefly so that any contrast in the subcutaneous tissue can be aspirated back through it if the department protocol allows; then remove the cannula and apply a dry dressing.
3. Elevate the affected arm above heart level to encourage reabsorption and reduce dependent edema.
4. Apply a cold compress (ice pack wrapped in a cloth, roughly 15-20 minutes at a time) for iodinated contrast. Cold reduces local blood flow, limits spread, and reduces pain. Warm compresses are used for vasoconstrictive extravasations, not for contrast.
5. Assess and mark the border of the swelling with a skin marker and a timestamp so progression can be tracked objectively.
6. Notify the radiologist immediately - the supervising physician decides on follow-up and on how the study is completed.
7. Do not start a new IV in the same arm. Document the event in the RIS, complete an incident report, and give the patient written and verbal instructions on warning signs and who to call.

Severity is judged by volume and site plus the physical findings, not by the patient's pain score alone.

This event looks moderate, not severe: the volume is roughly 40 mL, the site is the antecubital fossa (a compliant, high-flow area), capillary refill is normal at 2 seconds, and there is no blistering or skin breakdown. Most extravasations of this size resolve with conservative care over hours to days.

Escalate to a same-day surgical/medical evaluation for:

• Compartment syndrome signs - pain out of proportion, pain on passive stretch, a tense or woody compartment, paresthesia, pallor, or capillary refill that worsens rather than normalizes. This is a surgical emergency.
• Skin changes - blistering, ulceration, or dusky, mottled skin suggesting ischemia.
• Large volume - commonly cited thresholds are greater than 100 mL, or greater than 50 mL at a site with less soft-tissue compliance (hand, wrist, foot, ankle).
• Progression - swelling that continues to enlarge after 2-4 hours, or increasing pain.

Note the risk profile: a 20-gauge cannula in a large arm and a 4 mL/s flow rate are both reasonable, but high BMI increases the chance of the cannula tip being short of, or through, the vein wall. Check for that possibility in the documentation.

Frame the question as: is the diagnostic question already answered, and if not, what is the safest way to answer it?

1. Review what was acquired before anything else. The injection stopped at ~40 mL - enough may have reached the pulmonary arteries to be diagnostic, especially since the acquisition may already have triggered. If the pulmonary arteries opacify adequately, no further contrast is needed; the radiologist decides.
2. If the study is nondiagnostic, the options are, in order of preference:
   • New IV in the contralateral arm (avoid the injured limb entirely) and a repeat of only the needed portion, after radiologist approval and with the extravasation documented first. Take a moment to assess the new site carefully - a second extravasation in the same patient is a reportable quality event.
   • Non-contrast or alternate study - V/Q scan, or lower-extremity venous ultrasound if the question can be reframed - depending on the patient's stability, chest radiograph, and pretest probability.
3. Do not let the extravasation drive a delay in a patient who may have a PE. Escalate to the radiologist and the referring team early so that the clinical pathway does not stall while the arm is being iced.
4. Escort and observe - keep the patient in the department until the swelling has been assessed and instructions given; document the plan, the responsible clinician, and the follow-up contact in the record.