extravasation

Extravasation is the unintended leakage of intravenously administered fluids, drugs, or contrast from a vessel into surrounding tissue. When the leaking agent is a vesicant or irritant, tissue injury can occur. Infiltration, by contrast, refers to leakage of non-vesicant IV fluids that typically causes milder swelling without tissue necrosis.

Common contexts include chemotherapy extravasation, where vesicant anticancer drugs leak into tissue; extravasation of contrast media during diagnostic imaging; and accidental leakage of vasopressors or other irritants from an IV line. High-risk agents include vesicant chemotherapy drugs and certain concentrates or hyperosmolar solutions. Peripheral IV access, small veins, and pediatric or elderly patients increase risk.

The pathophysiology involves direct chemical injury to tissue, inflammation, and disruption of microcirculation, which can progress to edema, blistering, necrosis, and functional loss if untreated. Early recognition is crucial, as symptoms may precede visible damage. Signs include sudden sharp pain at the infusion site, burning or stinging, swelling, redness or blanching, cooler skin, and, in severe cases, blistering or necrosis.

Management centers on rapid intervention. The infusion is stopped immediately, and the cannula is left in place if possible to aspirate residual drug and minimize further leakage. Depending on the agent, temperature therapy (cold for many agents, warm for others) may be used, and measures to reduce tissue injury are applied. Specific antidotes may be used for certain extravasations (for example, hyaluronidase for subcutaneous leakage to facilitate dispersion, phentolamine for vasopressor-induced injury). Reviews with the treating team and, if needed, surgical consultation are advised for extensive damage.

Prevention focuses on secure IV access, using central lines for high-risk agents, careful site selection, regular monitoring of the infusion site, and prompt response to any signs of leakage. Prognosis varies with injury severity and timeliness of treatment.