A nurse is caring for a patient receiving a vesicant chemotherapy agent via peripheral IV. Which sign would most likely indicate extravasation?

A. Blistering and ulceration around the IV site is correct because vesicant chemotherapy agents, such as doxorubicin, vincristine, or cisplatin, are highly irritating to tissues. If these drugs escape the vein (extravasation), they cause tissue necrosis, blistering, ulcer formation, and severe pain. Immediate interventions include stopping the infusion, leaving the catheter in place for possible antidote administration, elevating the limb, and notifying the provider. Early recognition is crucial to prevent permanent tissue damage. B. Rapid infusion rate is incorrect because while a fast infusion rate can increase the risk of vein irritation or infiltration, it is not a clinical sign of extravasation. Extravasation refers specifically to the leakage of vesicant medication into surrounding tissue, not just infusion speed. Rapid infusion might cause discomfort or minor swelling but does not directly indicate tissue damage. C. Coolness and pallor at the IV site is incorrect because these are classic signs of infiltration, where a non-vesicant fluid (e.g., saline or isotonic solutions) leaks into surrounding tissue. Infiltration typically causes swelling, discomfort, and a cool sensation but does not result in tissue necrosis or blistering, which distinguishes it from vesicant extravasation. D. Redness and warmth at the IV site is incorrect because this usually indicates phlebitis, an inflammation of the vein caused by mechanical irritation, chemical irritation from medication, or infection. Phlebitis presents with pain, redness, warmth, and sometimes a palpable cord along the vein, but unlike extravasation, it does not cause blistering, ulceration, or necrosis unless severe and untreated.