Extravasation Risk Factors - The Patient

Despite the theoretically correct sites for cannula location, a number of other patient factors come into play.

Disease parameters such as lymphodema in breast disease, or other underlying physiological conditions, such as diabetes and peripheral circulatory diseases such as Raynaud's disease; can all modify this theory.

Patients who have had previous radiation therapy at the site of injection may develop severe local reactions from extravasated cytotoxic drugs. This is known as recall injury and has been noted in patients who have received doxorubicin.16 Cytotoxic drugs also have the potential to cause cutaneous abnormalities in areas that have been damaged previously by radiation, even of the areas are distant from the injection site. Furthermore, areas of previous surgery where the underlying tissue is likely to be fibrosed and toughened all dramatically increase the risk of extravasation.

Because of the toxic chemical nature of many cytotoxic drugs and because of the stress and trauma involved in the cannulation process, combined with the fact that chemotherapy is given over a number of cycles on a three-weekly or even weekly basis; it is thought by many that the sites of cannulation should be alternated.

A final factor to be worked into this complicated equation is the patient's preference. Often patients do not wish to be cannulated in their dominant hand and, in fact, there is some evidence to suggest that this is a more complicated, more traumatic process anyway because the underlying muscular structures of the dominant hand or arm are better developed and therefore apply greater pressure to the vascular structures which they surround.

Infants and Young Children 20 29 36 43 45

• Most extravasations in children occur in infants under 6 months. 43
• Severe damage is more common in neonates and young children than in adults. 62
• Infants in special care baby units are particularly at risk because of their immature skin, the frequent need for prolonged antibiotic therapy, intravenous electrolyte and nutritional supplementation, 43 and because they often have infusions through peripheral veins. 29
• Infants and young children may not be able to localise and report pain. 71

The Elderly 16 18 32

• These patients may pull or interfere with their cannulas because of confusion.
• They may be unable to report pain due to conditions which reduce pain sensation.
• Fragile skin and veins, and general debility may increase susceptibility to extravasation. 59

Patients Unable to Communicate 24 25 32 45

Reduced levels of conciousness or verbalisation difficulties may result in extravasations going unnoticed.

Those at risk include :

• Patients under general anaesthesia. 61 63
• Patients intubated in the intensive care unit. 61
• Heavily sedated or comatose patients. 63
• Patients undergoing cardiac resuscitation. 63
• Stroke or paralysed patients.