Problems Associated with Cannula Insertion - Extravasation & Infiltration Injuries - An Overview

A potential claim for damages can arise from a patient suffering an extravasation or infiltration injury after cannula insertion.

What is an extravasation injury?

An extravasation injury is the inadvertent leakage of a solution that is vesicant. This means any medicine or fluid with a potential to cause blisters, severe tissue injury (skin, tendons or muscle) or tissue death if it escapes away from the intended venous pathway.

Extravasation can result in mild skin reactions to severe tissue death and sometimes amputation is the only treatment option. Other possible complications associated with an extravasation injury include infection, complex regional pain syndrome, and loss of limb function.

What is an infiltration injury?

Extravasation is different from infiltration. Infiltration is the inadvertent leakage of a non – vesicant solution away from its intended vascular pathway into the surrounding tissue.

Infiltration does not lead to tissue death. However, it can be associated with problems. If a large volume of medicine or solution it may cause redness, swelling, and discomfort around the site and can even cause nerve compression and acute limb compartment syndrome, sometimes resulting in long term disability.

Surgical intervention may be required ie fasciotomy to relieve nerve compression (pins and needles to loss of feeling or movement) and compromised blood circulation to a limb.

There are many risk factors

Peripheral and central venous cannulas/catheters can both cause extravasation injuries. These may include the type of cannula used ie butterfly needles (metal/steel), large sized catheters relative to the vein size it’s inserted into, and cannulas inadequately secured.

Cannulas can also be inserted into undesirable locations eg antecubital fossa (elbow crease area), the back of the hand or at the wrist, plus repeated use of the same vein increases the risk of an extravasation injury as well.

The volume of the vesicant drug/fluid infused, its concentration, pH (extremes of acidity or alkalinity), and osmolarity, affect the resultant damage. Drugs that cause blood vessels to constrict eg noradrenaline and cytotoxic agents are associated with tissue death if they extravasate.

Age

The extremes of age –the very young and old, and patients with small fragile or thrombosed veins are at increased risk from extravasation injuries. As are patients with altered sensory perception (post stroke), poor understanding of risk, patients with lympoedema or the active patient.

There are associated clinician risks, such as lack of knowledge/unfamiliarity of central venous catheters use and management, as well as distraction.

Signs of injuries

Signs of infiltration injuries present as coolness or blanching at the cannula insertion point/swelling, tenderness or discomfort/taut or stretched skin/leakage of fluid at the cannula insertion point, inability to obtain blood return/change in quality or flow of the infusion or injection/numbness, tingling –‘ pins and needles’.

Extravasations signs also include:- burning, stinging pain/redness followed by blistering,tissue death and ulceration.

Extravasation injuries are graded (1 - 4) according to the severity of the injury. Severe injuries often require plastic surgical intervention.

Good practice includes that the access device should be well secured. The needle port should be observed before administering any vesicants or irritant fluids. The patency of the vein and catheter should be assessed before administration. The pressure of the infusion pump monitored and a rise in pressure or a change in flow investigated, the infusion site should be regularly inspected during the duration of the infusion.

Early intervention & monitoring

It is crucial that early recognition and intervention of an extravasation or infiltration injury occurs so to minimise the impact on tissue damage.

It is a medical emergency and the responsibility of medical staff administering intravenous therapy to be competent to undertake the procedure and maintain knowledge and skill. Close monitoring should be adhered to throughout the infusion. Once an infiltration/extravasation injury is suspected relevant medical staff should be alerted, as well as elevation. Often, initially the catheter involved is left in place and if possible the site where the injury has occurred elevated.

Individual Hospital Trusts should have their own policies in place for the management and treatment of infiltration/extravasation injuries.