Peripheral Cannulas

Peripheral cannulas

A cannula is a flexible tube containing a needle (stylet) which may be inserted into a blood vessel (Dougherty 2008, RCN 2010). Cannulas are usually placed in the peripheral veins in the lower arm but may also be placed in the veins of the foot (an area used particularly in paediatric care) (Weinstein and Plumer 2007). However, veins of the lower extremities should not be routinely used in adults due to the risk of embolism and thrombophlebitis (INS 2011, RCN 2010).

The advantages of using a peripheral cannula are that they are usually easy to insert and have few associated complications; however, they are associated with phlebitis (either mechanical or chemical) and require constant resiting (Dougherty 2008, INS 2011, RCN 2010).

INDICATIONS

Short-term therapy of less than a week.

Bolus injections or short infusions in the outpatient/day unit setting (Hadaway 2010, RCN 2010).

CONTRAINDICATIONS

Long-term intravenous therapy.

Longer or continous infusions of medications that are vesicant or those that have a pH >9 (Hadaway 2010).

IMMEDIATE CARE

Once sited, the peripheral cannula should be flushed using a pulsatile flush, ending with positive pressure (Dougherty 2008, RCN 2010, Weinstein and Plumer 2007). The cannula should be secured using clean tape or a securing device. Non-sterile tape should not cover the insertion site and taping should enable the site to remain visible and the cannula stable (Figure 12.28). Securement devices are now available and reduce the risk of dislodgement and other complications (Bausone-Gazda et al. 2010, Moureau and Iannucci 2003). A dressing should be applied: this can be either a transparent dressing or low-linting gauze (Perucca 2010). Once the gauze is in place, a bandage may be applied. However, transparent dressings, particularly moisture-permeable dressings, should not be bandaged as the visibility and moisture permeability are obscured.

ONGOING CARE

A peripheral cannula should be flushed before and after each use to check for patency prior to administration of a medication, and at least daily if not in use, using 0.9% sodium chloride. The dressing should be changed as required (if transparent) or each time the device is manipulated (gauze). The site should be monitored daily or when the device is used. The site should be inspected for signs of infiltration, extravasation and leakage and using a scale such as the VIP Scale for signs of phlebitis (DH 2010). The Visual Infusion Phlebitis Scale (VIP) was developed by Jackson (1998) and measures the signs and symptoms of phlebitis, matching them to the appropriate management. Each stage has a numbered score and this is recorded by nursing staff at regular intervals and, where necessary, the corresponding action is taken (Groll et al. 2010, Morris 2011). However, there is now debate as to the efficacy of these phlebitis assessment scales (Ray-Barruel et al. 2013).

(Royal Marsden 2015)

REMOVAL

It has been recommended that peripheral devices should be resited every 48–72 hours (Barker et al. 2004, DH 2012) but some literature supports dwell times (length of time cannula in situ) of up to 96 hours with no significant complications providing that non-irritants are administered (Homer and Holmes 1998, McGoldrick 2010, Palese et al. 2011). Other studies have found that drug irritation is the most significant predictor of phlebitis and infiltration, rather than dwell time, and that extending the dwell time up to 144 hours could be considered under certain circumstances (Bregenzer et al. 1998, Catney et al. 2001).

The Rickard et al. (2012) study of over 5000 peripheral cannulas found no difference in phlebitis, infection or failure rates between replacing cannulas every 3 days compared with leaving in situ and replacing when clinically indicated. They concluded that peripheral devices need only be removed as clinically indicated and that this would save millions of unecessary resites, associated discomfort and a reduction in cost of both equipment and staff time. This is supported by van Donk et al. (2009) and Webster et al. (2008) who recommend resiting cannulas based on clinical indication instead of time in situ. Lee et al. (2009) also state that this approach does not increase infection rate but they do recommend that insertion is done by highly skilled IV teams or rates could increase. Finally, Epic3 now recommend that peripheral cannulas should only be resited when clinically indicated and not routinely (Loveday et al. 2014).

Removal of the intravenous device or cannula should be an aseptic procedure. The device should be removed carefully using a slow, steady movement and pressure should be applied until haemostasis is achieved. This pressure should be firm and not involve any rubbing movement. A haematoma will occur if the device is carelessly removed, causing discomfort and a focus for infection (Perucca 2010). The site should be inspected to ensure bleeding has stopped and should then be covered with a sterile dressing (INS 2011). The cannula integrity should be checked to ensure the complete device has been removed (Dougherty 2008, INS 2011, RCN 2010). The date, time and reason for removal of the cannula must be documented in the patient’s notes (DH 2011, Dougherty 2008, RCN 2010). This documentation ensures adequate records for the continued care of the device and patient as well as enabling audit and gathering of statistics on rates of phlebitis and infiltration.