extravasate

Extravasate is a term used in medicine to describe the leakage of a fluid from a vessel into the surrounding tissue. In clinical contexts, extravasation refers to the escape of intravenously administered drugs, fluids, or contrast media into the tissue, often with local injury. The related noun extravasation describes the event. It is distinct from infiltration, which is leakage of non-vesicant fluids into tissue without tissue damage.

Common contexts include intravenous therapies, especially irritant or vesicant medications such as certain chemotherapy agents, hyperosmolar solutions, and iodinated contrast agents used in imaging. Extravasation can also occur with arterial access or central venous catheters, though it is less frequent.

Signs range from early burning, pain, and swelling at the infusion site to delayed redness, blistering, skin discoloration, and, in severe cases, tissue necrosis, ulceration, or nerve injury. Suspected extravasation requires prompt assessment to determine whether a vesicant is involved and to guide management.

Management typically starts with stopping the infusion, and, if possible, leaving the cannula in place to aspirate residual drug before removing it. The site is then treated according to protocol, with limb elevation and appropriate temperature therapy (cold or warm compress depending on the agent). Some drugs have specific antidotes or protocols (for example, certain chemotherapeutic agents use dexrazoxane), so institutional guidelines should be followed. Severe injuries may require surgical evaluation.

Prevention emphasizes proper IV technique, considering central venous access for vesicant or irritant therapies, ensuring patency, securing the cannula, selecting appropriate concentrations, and close monitoring of the infusion. Documentation and patient education are important components.