Injection Extravasation During a Cardiac Stress Study
During a Tc-99m sestamibi rest injection for a myocardial perfusion study, the technologist notes resistance and pain at the antecubital IV site. The patient reports burning. The dose was 10 mCi in 1 mL. The technologist stops the injection after approximately half the volume. There is swelling and erythema at the site. The stress portion is scheduled for later the same day. The supervising physician is in another room.
1. List the immediate actions and the order in which you would take them.
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- Stop the injection immediately. 2) Assess the patient: pain, swelling, color, capillary refill, distal pulses. 3) Notify the supervising physician and document. 4) Apply conservative measures per institutional policy (elevation, cold or warm compress depending on agent and policy; do not massage). 5) Estimate the extravasated activity and record it. 6) Notify the physician so the study interpretation and dose can be adjusted. 7) Follow up with the patient. The key judgment is that patient safety and physician notification precede any attempt to salvage the dose, and that the extravasation must be documented and considered when interpreting the images.
2. How does the extravasation affect the rest images and the planned same-day stress study, and how would you adjust?
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Extravasated activity near the injection site creates intense focal uptake that can cause scatter and a 'shine-through' artifact, and it means the patient received less than the intended dose, lowering count statistics. The rest images may show a hot spot at the antecubital region and degraded myocardial counts. For the same-day stress study, the residual extravasated activity will still be present and can contaminate the stress images, and the stress dose must be adjusted upward to compensate for the reduced rest dose if the protocol relies on a fixed ratio. Options: use a different injection site (opposite arm) for the stress dose, increase the stress dose within allowable limits, and image the stress acquisition with attention to shielding or positioning to keep the injection site out of the field of view. Discuss with the physician whether the rest study is interpretable or should be repeated.
3. What documentation and follow-up are required, and what quality metric does this event feed?
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Document the time, agent, activity and volume intended vs administered, estimated extravasated activity, symptoms, immediate interventions, physician notification, and follow-up plan. Report through the institution's event-reporting system. This feeds extravasation rate as a quality metric and should trigger review of IV placement technique, vein selection, and injection monitoring. Follow-up should include checking the site at the end of the visit and instructing the patient to report worsening pain, blistering, or numbness. Do not alter the administered-dose record to hide the event; accurate records are needed for dose reconstruction and interpretation.