Last updated: Friday, May 06, 2016

Extravasation injury in a child
A complication of giving intravenous medicines is extravasationExtravasation occurs when a medicine leaks from a blood vessel and causes injury to the surrounding tissue. The adverse consequences of this leakage depends upon whether the medicine is classed as:

- an irritant, meaning it can cause inflammation but not necrosis;

vesicant, which means it can cause irritation, vascular ulceration, and necrosis.

If a non-irritant medicine leaks from a blood vessel this is called infiltration.

There are a range of risk factors for extravasation including those related to the administration device (such as an inadequately secured cannula), those associated with the administrator (such as lack of familiarity with the device or medicine), and those related to the patient (such as extremes of age or small veins). Medicine-related risk factors that increase the risk of inflammation and tissue damage include:

  • pH of around less than 5 or greater than 9.
  • Osmolarity more or less than that of plasma (approximately 290 mOsmol/L). Most injections are formulated to have a similar osmolarity to plasma to reduce the risk of vein irritation but there exceptions.
  • Vasoconstrictive potential (extravasation of dopamine can cause ischaemic necrosis, for example).
  • Presence of certain excipients (such as alcohol or polyethylene glycol).
  • The volume of medicine or fluid that has entered the surrounding tissue.
  • Concentration of the medicine or fluid.
  • Potential of the medicine to precipitate (such as diazepam).
  • Ability to bind to DNA and/or kill replicating cells.

Extravasation injury in an adult
Courtesy of World Wide Wounds
The evidence base for managing extravasation is made up of small trials and case reports. Despite this, the BNF has some information on extravasation. In addition, your hospital is likely to have local guidelines if chemotherapy is given there, as these agents are commonly implicated in extravasation injury. Refer to the Information sources for more guidance on where to look, but the most important point to remember is that if you are asked about managing a case of extravasation, act quickly and ask for help – this is an urgent problem.