Extravasation is the accidental leakage of an intravenously administered drug solution from the vein into the surrounding body tissue.
Extravasation is reported to occur in between 0.1% and 6% of adults receiving intravenous (IV) drugs.
Extravasation is inevitable because some drugs or fluids can only be administered intravenously such as
- Chemotherapy drugs (doxorubicin, vincristine, cisplatin and paclitaxel)
- Antibiotics (vancomycin, meropenem and gentamicin)
- Antifungal drugs (micafungin and amphotericin)
- Pain medications (morphine).
Moreover, IV lines are vital for resuscitation and for real-time monitoring of patient parameters.
The degree of damage caused by extravasation is related to the following:
- Type of the drug
- Drug concentration, pH (both acidic and alkaline) and osmolarity
- Site of the extravasation
- Volume of infusion
- Length of the infusion
Extravasated drugs can be divided into 3 types according to their potential for tissue. They are described as:
- Vesicant: A vesicant is a liquid capable of causing blistering, sloughing or necrosis of tissues.
- Irritant: Drug that can cause a burning sensation in the vein while being administered: e.g., fluorouracil
- Non-vesicant: Inert or neutral drug that do not cause inflammation, damage or ulceration, but can cause pain at the injection site and along the vein: e.g., cytarabine.
Extravasation can cause serious complications, particularly if the drug is a vesicant as is the case for several chemotherapy drugs. Extravasation of chemotherapy is seen in 1% to 7% of adults receiving drugs IV.
Vesicant chemotherapies can be:
- DNA-binding: These drugs (e.g., anthracyclines, like daunorubicin ) are absorbed, enter the cells and bind to their DNA causing the death of the cell. The drug is then released from the dead cell ready to destroy other healthy cells. This leads to deep erosion of cells within the tissue.
- Non-DNA binding: These drugs (e.g., vinca alkaloids like vincristine) cause cell death without binding to the cell’s DNA, therefore they are easily metabolised and removed from tissues. Tissue damage remains local and recovers eventually.
Extravasation of vesicant chemotherapies, such as vincristine, daunorubicin and doxorubicin, can cause serious injuries from damage or necrosis of the surrounding tissues. Urgent treatment is required.
Extravasation of other vesicants such as contrast media and vasopressors can also cause serious damage of tissues.
There are 4 different types of tissue damage that can occur following extravasation:
- Vasoconstriction: Narrowing of the blood vessels
- Osmotic: Diffusion of a soluble fluid from an area of low concentration to one of higher concentration
- Infusions of a drug with an osmolarity different to that of the body can irritate the lining of the vein and destroy the cell proteins. The physiological osmolarity is around 281 mOsm/L.
- pH-related: Associated with the acidity of a substance. pH is a scale of acidity from 0 to 14. The more acidic a solution, the lower its pH.
- Infusions with a pH different to that of the body can irritate the venous endothelium and vessel wall and can damage the cell proteins and cause cell death. Physiological pH is around 7.35.
- Consequently acidic drug solutions (pH<7) and alkaline drug solutions (pH>8) can damage vein linings.
- Cytotoxic: Harmful and destructive to body cells
