An intravenous catheter care bundle is defined as a collection of processes needed to effectively and safely care for patients (Boyd et al, 2011) and significant improvement in intravenous catheter management was reported by Boyd et al (2011) after the implementation of a catheter care bundle in humans. Care bundles provide evidence-based guidance for the maintenance and assessment of intravenous catheter sites (Higginson, 2011). Although an intravenous catheter care bundle check-list does exist for small animal patients, no such care bundle is available for equine patients. The creation and implementation of an evidence-based intravenous catheter care bundle could assist registered equine veterinary nurses (REVNs) to significantly improve patient care and therefore contribute to the development of equine clinical practice.
Self-disinfecting catheter hubs
In human research, a new self-disinfecting catheter hub (Figure 1) has been used; the Curos® Port Protector (Ivera Medical) is a simple, innovative, disposable infection prevention product intended for use on swabbable luer access valves as a disinfecting cleaner prior to catheter access and to act as a physical barrier to contamination between catheter accesses. Curos® will disinfect the valve 3 minutes after application and act as a physical barrier to contamination for up to 7 days if not removed. Inside the Curos® Port Protector is a 70% isopropyl alcohol saturated sponge-like foam. Once secured, the Curos® Port Protector automatically provides effective, consistent and reliable passive disinfection of the port. It has been shown to reduce sepsis by 90% (Sitges-Serra et al, 1997). This alone is a dramatic reduction in the number of cases of sepsis, and such a reduction would be extremely valuable in high risk equine patients (Sitges-Serra et al, 1997). In veterinary medical research, 70% of all intravenous catheter-related infections occurred through the catheter hub itself (Tan et al, 2003). In human and veterinary research it has been suggested that environmental factors and poor management can influence catheter-related sepsis (Leonidou and Gogos, 2010). Improving catheter management during insertion and post catheterisation will help reduce thrombophlebitis in high risk patients (Sitges-Serra et al, 1997). Conducting regular catheter hub cultures, reducing the number of lumens a catheter may have and providing a high level of aseptic handling of catheter hubs could also help to minimise sepsis (Sitges-Serra et al, 1997). Routine catheter hub cultures should be performed, and if any of these cultures are positive for Staphylococcus, Streptococcus and Micrococcus species (Geraghty et al, 2009a), then the catheter should be removed before the vein is affected.
According to Sitges-Serra et al (1997), in human medicine the hub is the main portal of entry for microorganisms. In their work, by minimising the amount of hub manipulation and improving aseptic technique, sepsis was reduced from one episode every 49 catheter days, to one episode every 375 catheter days. Improving practice cleaning standards and regular hand washing can help reduce the spread of harmful bacteria (Aberra, 2012). Performing regular hub cultures is not widely practiced in veterinary medicine despite it having been recommended in humans by Sitges-Serra et al (1997). There has been no research in veterinary medicine that has found it beneficial in equine patients. However, it could help prevent contamination of the catheter port and therefore infection in intensive care patients as potentially harmful bacteria could be detected and prevented from colonising the catheter.
Bandaging catheter sites
According to Divers (2003), bandaging catheter sites can help to restrict catheter movement and protect the catheter from contamination with bedding and faeces (Adams and Niles, 1999). Divers (2003) believed that this is only necessary if the patient is getting down and rolling. In contrast Adams and Niles (1999) suggested that they should be bandaged regardless to protect from the external environment. There is no real evidence to prove that bandaging is successful in reducing sepsis rates, but it would seem more beneficial to bandage an intravenous catheter if the patient is likely to roll in faeces so bacteria are not introduced to the catheter site. Excessive catheter movement is thought to contribute to thrombophlebitis as this irritates the lumen of the vein (Harold and McKenzie, 2008). Research has shown that patients that undergo painful procedures have a higher risk of thrombophlebitis (Divers, 2003). This is believed to occur due to the manner in which horses respond to pain by rolling in their bedding which contains bacteria (Divers, 2003).
Using topical antiseptic preparations to cover catheter sites is controversial in veterinary medicine even though they may reduce gross contamination (Tan et al, 2003). However in human research topical antiseptic preparations have helped to reduce the amount of residual skin flora and it could potentially be worth trying such an approach in equine patients. Bashir et al (2012) found that chlorhexidine gluconate impregnated dressings can help to reduce the amount of residual skin bacteria at intravenous catheter sites in human patients. Chlorhexidine gluconate impregnated dressings reduced catheter-related blood stream infections 1.3 per 1000 catheter days to 0.4 per 1000 catheter days (Bashir et al, 2012). This positive outcome shows how valuable an antimicrobial impregnated dressing can be in the prevention of thrombophlebitis.
Culturing intravenous catheters
Leonidou and Gogos (2010) believed in treating catheter-related sepsis according to the pathogen responsible. In veterinary practice, catheters are often removed regardless of the pathogen causing the complication. Tan et al (2003) found that 6.9 to 14.3% of all equine patients that are catheterised have some degree of colonisation by bacteria. Therefore performing routine cultures could help protect patients by identifying harmful bacteria before they colonise the catheter and this could enable prophylactic treatment to be instigated to prevent infection. In high risk equine patients the incidence of catheter sepsis is as high as 85% in patients with diarrhoea and 83% in foals (Tan et al, 2003).This indicates that patients with diarrhoea and foals are at high risk of catheter sepsis. Taking cultures from the catheters of these high risk patients could enable the harmful bacteria to be identified in these patients and targeted treatment could then take place. This could potentially lead to successful prevention of thrombophlebitis. Depending on which bacteria are cultured, the catheter could either be removed or antibiotics could be flushed through the catheter at regular intervals (Leonidou and Gogos, 2010). Lack of research into performing routine catheter cultures in veterinary medicine does highlight a need for further study in this area.
Catheter dwell time and material
Hay (1992) suggested that replacing intravenous catheters every 48–72 hours would reduce the risk of thrombophlebitis. However this could cause more trauma to the vein and increase the likelihood of thrombus formation. According to Chau et al (2008), however, bacterial colonisation of catheters increases after 72 hours, therefore risk to the vein is reduced by replacing catheters every 48 to 72 hours. Traub-Dargatz and Dargatz (1994) stated that every time a catheter is inserted a fibrin sleeve forms around the catheter and this predisposes the patient to thrombus formation. Malach et al (2006) found that prolonged catheter dwell time increased the incidence of thrombophlebitis in human patients. Therefore, catheters are replaced electively every 72–96 hours in human hospitals regardless of the catheter type (Martinez et al, 2009). Hay (1992) stated that Teflon catheters are known for being thrombogenic and are only suitable to stay in place for 3 days, however this would be too long in a critical care patient as the Teflon catheter material could have already irritated the vein by this time (Tan et al, 2003). Therefore the clinical condition of the patient should determine what type of catheter material is used (Corley, 2008). The preference in veterinary medicine is to leave a less thrombogenic catheter in situ for longer, in contrast with human medicine where the preference is to replace catheters more frequently to prevent them being colonised by bacteria. Veterinary medicine details that long stay catheters such as those made from polyurethane and silastic can stay in the vein for up to 2 weeks' duration (Hardy, 2012). Tan et al (2003) stated that catheters should be removed if thrombophlebitis is suspected and re-inserted at an alternative site. A study performed by Lankveld et al (2001) identified that the longer the catheter dwell time in an equine patient's vein the more likely the patient would be to develop thrombophlebitis. A self-disinfecting catheter hub or chlorhexidine gluconate impregnated dressing could be useful in those cases where it is necessary that a catheter is kept indwelling for a long period of time.
Intravenous catheter care bundle for horses
Care bundles have been used in humans internationally with huge success in reducing intravenous catheter complications (Boyd et al, 2011). The main components of human catheter care bundles are described by McCallum and Higgins (2012) and are summarised as follows:
Guerin et al (2010) demonstrated that implementation of a catheter care bundle was associated with a significant reduction in central line associated bloodstream infections. Boyd et al (2011) also demonstrated a significant improvement in the management of peripheral venous catheter management by using a care bundle approach. Although both these studies were conducted in human patients it would be reasonable to assume that some components of the human care bundles could be used successfully with equine patients. Components such as strict hand hygiene before and after touching the catheter, checking the site daily and using a protective dressing could all be transferred to equine patients. The development of an evidence-based intravenous catheter care bundle for horses could help to reduce the incidence of thrombophlebitis. The following is a suggestion for an equine intravenous catheter care bundle.
Content of an equine catheter care bundle
A number of important factors should be considered within an equine catheter care bundle:
Conclusion
Self-disinfecting catheter caps and dressings can be used to reduce catheter complications in horses. If complications do occur the catheter and cap should be cultured as part of an evidence-based treatment protocol. The appropriate catheter material should be selected for use after individual assessment of the patient. Application of an equine intravenous catheter care bundle could facilitate evidence-based nursing practice and raise the standards of care for equine patients. Recommendations for an equine intravenous catheter care bundle should however be implemented with caution as specific studies on the care of intravenous catheter sites in horses are lacking. Clinical audit could be used alongside the implementation of the care bundle to provide an unbiased means of monitoring protocol changes, and this would serve to ensure that patient welfare is not compromised.