The Veterinary Nurse - Urinary catheters: indications for use and management

Abstract

There are numerous reasons why veterinary patients would benefit from the placement of an indwelling urinary catheter (IDUC), however the veterinary surgeon must assess the benefits of this indwelling device for each patient individually against the potential risks, of which there are many. This article aims to discuss the indications for the use of an IDUC considering optimal management, linked to the prevention of associated infections. The key risks and complications associated with their use will be outlined as it is important that all veterinary professionals work together to prevent their development.

Indwelling urinary catheters (IDUC) are indicated in cases of acute kidney injury (AKI), where the patient is already anuric or the veterinary surgeon (VS) believes the patient is tending towards oliguria (Balakrishnan and Drobatz, 2013). The accurate assessment and measurement of urinary output (UOP) in these patients is essential to monitor the progression or deterioration of renal function (Lane, 2009), as Balakrishnan and Drobatz (2013) advocated aggressive fluid administration to promote diuresis and attempt to reverse azotaemia. Balakrishnan and Drobatz (2013) also advised that IDUC are warranted in patients with uroabdomen, for example in patients that have experienced trauma and associated bladder rupture. These patients are likely to have a percutaneous transabdominal drainage catheter placed, however an IDUC specifically helps in these cases to ensure continuous bladder decompression to reduce the risk of ongoing leakage of urine from the bladder during the healing process (Lane, 2009).

Feline urethral obstruction (FUO) is a common indication for IDUC placement in feline patients, whether the obstruction is a result of feline idiopathic cystitis (FIC), uroliths, environmental factors and associated stress, crystalluria or mucus plugs (Balakrishnan and Drobatz, 2013; Cooper, 2015; Orme, 2015). In dogs, urethral obstruction may also be caused by urethral calculi, and additionally strictures or neoplasia; the latter two problems could also affect cats (Lane, 2009). Similarly, trauma to the urinary tract could warrant the placement of an IDUC to facilitate healing (Lane, 2009); the IDUC will, for example, allow a patient to void urine without the urine physically coming into contact with a healing urethra.

Guptill (2015) advocated the placement of IDUC in surgical patients for a number of reasons, which include: emptying the bladder before surgery commences; to assist in surgeries to the urinary tract itself; to facilitate hydropropulsion during surgery if required; to monitor UOP and thus renal perfusion while the patient is under general anaesthesia; to prevent urine contamination of the surgical field; and finally, thinking ahead to the postoperative period where the patient may be recumbent and urinary retention is a risk. Similarly, Rose (2014) specified that IDUCs are a useful intervention for paralysed and paretic patients, where mobility issues are significant and prolonged recumbency likely; this could help maintain a patient's hygiene and prevent urine scalding (McDonald, 2017), and this situation can also relate to many critical and intensive care patients.

Multiple authors have discussed the use of IDUC in patients with disorders of micturition until the underlying cause has been established (Aldrich, 2006; Lane, 2009; Guptill, 2015; Langfitt et al, 2017). Lane (2009) and Guptill (2015) discussed the use of urinary catheters to facilitate sample collection for analysis, for the introduction of contrast media during radiographic work-ups, and for instilling medications; however, these situations generally do not require the catheter to be left in situ long-term.

Management

Guptill (2015) expressed that the primary goal of all veterinary professionals is keeping their patients healthy, and a large focus in relation to maintaining their health in practice concerns the prevention of hospital-associated/acquired infections (HAIs). Catheter-associated urinary tract infections (CAUTIs) are a form of HAI and are un-fortunately a potential complication associated with the use of IDUCs (Aldrich, 2006; Oosthuizen, 2011; Brown, 2013; Balakrishnan and, Drobatz 2013; Orme, 2015; Stull, and Weese 2015; McDonald, 2017), therefore all veterinary practitioners should be mindful of this fact when nursing patients with IDUCs in order to minimise the risk of development. Stull and Weese (2015) explained that in reality it is inevitable this will occur for many reasons, including bacterial adaptation and the complexity of many pathogenic organisms. Consequently, Stull and Weese (2015) categorised methods to reduce the risk of HAIs, including CAUTIs, in six ways:

Hand hygiene and the use of personal protective equipment (PPE)

Cleaning and disinfection

Surveillance

Patient management

Antimicrobial stewardship

Education and training.

Hand hygiene

Proper hand hygiene techniques, washing with soap and water or using alcohol-based rubs, is fundamental in reducing the risk of HAIs such as CAUTIs (Aldrich, 2006; Guptill, 2015; Stull and Weese, 2015), and is a simple and effective intervention as long as every veterinary professional performs hand hygiene effectively. The use of appropriate PPE is essential, including sterile and non-sterile gloves and gowns/aprons, to protect both the staff member and patient from contamination with pathogens.

Cleaning and disinfection, and surveillance

Cleaning and disinfection is paramount to infection control in veterinary practice, and all practices should ensure they have strict protocols in place to maintain a hygienic environment for staff and patients alike. This encompasses effective cleaning of all practice equipment, the cleanliness of all surfaces, and using appropriate disinfectants in accordance with manufacturer instructions (Guptill, 2015; Stull and Weese, 2015). Stull and Weese (2015) also discussed surveillance as an important method of reducing the risk of HAIs by detecting them early, and they advocated the appointment of an infection-control officer/practitioner in all practices. This person can lead in the development of surveillance programmes tailored to the practice and co-ordinate the routine collection and assessment of samples from around the practice to monitor the effectiveness of hygiene protocols. Implementing such a regimen in veterinary practice can only have a positive effect on reducing the occurrence of HAIs, including CAUTIs. Guptill (2015) also stressed the importance of routine, strict infection control protocols and regular audits in relation to the management of patients with IDUCs.

Patient management

Patient management is extremely important in HAI reduction and prevention considering the regular close contact between veterinary staff and their multiple patients. Along with other methods of reducing HAI risk, Stull and Weese (2015) discussed isolating relevant patients, utilising dedicated medical equipment for individual patients, and patient cohorting according to their risks; specific staff members could be dedicated to specific groups of patients each day to minimise the risk of spreading pathogens between patients of differing vulnerabilities. Patients with IDUC are vulnerable to HAI development in the form of CAUTIs, therefore having dedicated veterinary staff managing their nursing care is advisable.

Antimicrobial stewardship

The use of antibiotics needs to be considered in veterinary practice, and their judicious use is extremely important in combatting the development of multidrug-resistant organisms (MDRO) (Stull and Weese, 2015). If no bacterial urinary infection has been confirmed then antimicrobials should be avoided (Guptill 2015), and where it is suspected, ideally a culture should be submitted to determine which drugs the bacteria are susceptible to.

Education and training

Education and training are vitally important in preventing HAIs, and this is particularly true in relation to the prevention of CAUTIs (Aldrich, 2006). Stull and Weese (2015) advised that educating all veterinary staff about disease and infection risks will help to enforce infection-control protocols, and education and use of protocols should extend to clients who are visiting their pets as well. Education of veterinary staff is essential in relation to the optimal management of IDUCs in order to reduce the risk of CAUTIs, and a protocol, such as that included below, is recommended for their placement and management.

Catheter placement and management protocol

Patient preparation

When cleaning around the insertion site gloves should be worn and sterile gauze swabs should be used, alternating between a chlorhexidine diluted in sterile saline (0.5–2%) solution, and just sterile saline alone (Guptill, 2015).

Hair around the insertion site should be clipped away (approximately 5 cm around in dogs and 2–3 cm in cats), and there should be no nearby long hair that poses a risk of overlapping the insertion (Guptill, 2015). The area should be cleansed as per the point above.

The prepuce of male dogs should be flushed using a 1:200 povidone iodine and sterile saline solution (3 to 5 times using 2–12 ml each time depending on the size of the dog, delivered using a sterile syringe) (Guptill, 2015; Thorp, 2016). Once the dog's penis has been exteriorised additional cleansing with the above solution may also be warranted.

In bitches, the vagina should be flushed as described for the male dog's prepuce, however the volume will vary between 0.5 and 12 ml per flush depending on the size of the patient (Guptill, 2015; Thorp, 2016).

In feline patients it is sufficient to simply clip away their hair as described, and prepare the skin around the insertion site as per point 1.

Prior to placement

Perform hand hygiene and don sterile gloves before placing a sterile drape over the work area, either a fenestrated drape or cut an appropriately sized hole with sterile scissors into a non-fenestrated drape (Guptill, 2015).

If there are any bulbs on the catheters they should be tested, and some catheters need lubricating/priming with sterile saline prior to placement (Guptill, 2015) (Figure 1).

Coat the tip of the catheter in sterile lubricant, ideally from individually sterilised packets of lubricant (Ackerman, 2016); some lubricants also contain local anaesthetics.

Figure 1. This Foley catheter needs lubricating / priming with sterile saline prior to use.

Placement and immediately following placement

Inserting the catheter in an aseptic manner is recommended by multiple authors (Aldrich, 2006; Guptill, 2015; McDonald, 2017).

Multiple authors advise connecting a closed collection system (CCS) immediately to the catheter following placement (Aldrich, 2006; Lane, 2009; Oosthuizen, 2011; Rose, 2014; Guptill, 2015; Ackerman 2016) (Figure 2).

As recommended by multiple authors, the catheter and CCS should be anchored to the patient to avoid the catheter being pulled out or to stop it kinking (Guptill, 2015; Rose, 2014; Thorp, 2016; McDonald, 2017). The catheter should be sutured securely to the perineum, and then tape can be used to anchor the CCS to the patient's tail and/or leg (Lane, 2009; Oosthuizen, 2011; Ackerman, 2016).

Place a buster collar on the patient (Guptill, 2015).

Figure 2. This is an example of a sterile closed collection system (CCS).

Daily maintenance

Perform hand hygiene and don sterile gloves (Guptill, 2015).

Every 24 hours clean the clipped area of the patient surrounding the catheter, and the external portion of the IDUC, using swabs and solutions as described in point 2 of the patient preparation section above; at least three scrubs with each solution (Aldrich, 2006; Oosthuizen, 2011; Guptill, 2015; Thorp, 2016; McDonald, 2017).

Check the patency of the tubing hourly (Guptill, 2015). The connections of the tubing all need to be thoroughly checked too, and if flushing is required this must be done using sterile saline and aseptic techniques (Oosthuizen, 2011), and this should be done directly through the catheter as opposed to flushing up through the CCS in case there is bacterial colonisation within the tubing distal to the patient (Ackerman, 2016).

It is good practice to gently palpate the patient's bladder every time the tube patency is assessed, and if the bladder is full it may indicate the catheter is not draining for some reason (Ackerman, 2016).

The CCS bag should be drained aseptically (Lane, 2009; Oosthuizen, 2011; Guptill, 2015); Rose (2014) recommended every 2 to 4 hours whereas Ackerman (2016) and McDonald (2017) recommended every 4 hours, however it is recommended the CCS is broken as infrequently as possible to reduce the risk of introducing bacteria into the system (Lane, 2009). It is recommended to monitor UOP hourly when checking the patency of the tube and empty the bag when it is full (but not full to the point of reflux risk).

Position the collection bag lower than the patient's bladder, and if this is on the floor as opposed to being suspended from the cage it must be sat in a clean litter tray, or another method of keeping it from contacting the floor should be employed (Oosthuizen, 2011; Guptill, 2015; McDonald, 2017) (Figure 3). The tubing can be secured to the patient's kennel inside and out to ensure the weight of the filling bag is not being supported by the patient in any way (Figure 4).

Retrograde flow of urine from the CCS bag towards the patient should be avoided in case there are resistant organisms in the urine and tubing (Guptill, 2015; Ackerman, 2016).

If the patient is ambulatory, the CCS tubing should be clamped off when they are walking and unclamped as soon as they are back in their cage to facilitate continued drainage (Guptill, 2015).

Prophylactic antibiotics should be avoided as they increase the risk of HAI (CAUTI) and MDRO development (Guptill, 2015). Antibiotics are only warranted in proven infections and their use should be targeted following a culture of the urine which will establish the sensitivity of any bacteria present in the sample to differing antibiotics.

At the time of catheter removal, if a CAUTI is suspected a urine sample should be cultured (preferably obtained via cystocentesis) (Guptill, 2015).

Figure 3. This closed collection system bag was secured to the front of the cage below so it was lower than the patient's bladder. The tubing was not long enough to facilitate it being sat in a clean litter tray on the floor.

Figure 4. There was plenty of tubing remaining in the patient's cage so they could freely move around without it pulling on their perineum. The tubing was then secured to the inside of the cage using tape before the remaining closed collection system tubing and bag were suspended below the level of the patient's bladder outside of the cage.

Potential risks and complications

There are many risks associated with the placement and management of IDUCs in veterinary patients that have been discussed in the literature; it is the veterinary professional's responsibility to be aware of these risks and potential complications, so they can follow strict protocols to prevent their development. Table 1 outlines the key risks and complications reported in the literature, along with clinical signs where relevant and any additional considerations for veterinary professionals to bear in mind.

Table 1. Risks, complications, clinical signs and considerations associated with IDUC

Risk/complication	Clinical signs/additional considerations
CAUTI/UTI/cystitis/ascending UTI especially if on systemic antibiotics or even in otherwise healthy patients/risk of reflux of contaminated urine from the CCS bag towards the patient	UTI: polyuria/polydipsia/haematuria/neutrophilic leucocytosis/urinary tenesmus/pollakiuria/dysuria/stranguria/pyrexia. Sanchez et al (2013) identified Escherichia coli in 47% of dog and cat urine in a study of 218 patients
Literature: Aldrich, 2006; Lane, 2009; Oosthuizen, 2011; Balakrishnan and Drobatz, 2013; Brown, 2013; Sanchez et al, 2013; Stull and Weese, 2015; McDonald, 2017
Blockage/obstruction/kinking of the IDUC (Figure 5)	Cessation of drainage/reduced UOP between two time intervals (Figure 6).Physically and visually check the catheter and all tubes and connections of the CCS before considering flushing.If there is still no drainage following the above checks and flushing if deemed necessary, the catheter should be removed and potentially replaced, and/or the veterinary surgeon (VS) should investigate whether the patient has developed anuria
Literature: Lane, 2009; Oosthuizen, 2011; Brown, 2013; McDonald, 2017
Self-removal/patient resistance/self-mutilation	Many patients do not appreciate/seem to find it uncomfortable having an IDUC in situ alongside the associated tubing of a CCS. The veterinary staff should ensure the equipment is all properly secured as previously described and place a buster collar on the patient as a preventative measure. Veterinary staff should regularly check the patient for signs of discomfort and unrest, ensure the catheter and CCS are still in situ, and observe for any self-mutilation type behaviours.Veterinary professionals should also be mindful of the potential negative affects an IDUC, CCS and buster collar can have on the patient performing other abilities, such as eating, drinking, getting comfortable to sleep, grooming and so on, and utilise a nursing care plan to help in the provision of holistic and well-managed supportive care (Figure 7)
Literature: Lane, 2009; Oosthuizen, 2011; Brown, 2013
Urethral damage/irritation/inflammation	Careful IDUC placement and management techniques can reduce the risk of these complications occurring. Additional irritation and inflammation of the urinary tract can prolong healing, increase patient discomfort, and potentially promote the development of a CAUTI
Literature: Lane, 2009; Brown, 2013
IDUC can further compromise the health of patients with diabetes mellitus, immune compromise, and coagulopathies or those at risk of bleeding	Due to the likelihood of any patient developing a CAUTI when they have an IDUC placed, those with concurrent systemic illnesses are naturally at greater risk of CAUTI development. Therefore the veterinary professionals should be extra vigilant in monitoring for signs of UTI development, and the VS has extra risks to weigh up against the benefits of IDUC use in their decision-making processes when devising a treatment plan.Similarly, those patients at risk of bleeding are a concern for veterinary professionals, and trauma to the urinary tract during the placement and management of IDUCs should be avoided by following proper and careful placement protocols as previously described
Balakrishnan and Drobatz 2013, Stull and Weese 2015. IDUC = indwelling urinary catheter; CAUTI = catheter-associated urinary tract infection; CCS = closed collection system

Figure 5. There was inadequate drainage from this patient's catheter due to a blood clot which could not be dislodged by flushing.

Figure 6. It is good practice to monitor urinary output between time intervals to help identify blockages or other drainage/urine production problems. This can easily be done when purpose made closed collection system bags featuring measurement lines on the outside are used, or can be achieved using tape stuck to the outside of the bag as in this picture.

Figure 7. This patient was very unimpressed with his buster collar and therefore refused to eat any food with it on.

Conclusion

IDUCs are essential for optimal patient management in a wide variety of situations. The accurate monitoring of UOP is vital in the assessment of patient health, facilitating the identification of both improvements and deterioration, and they are hugely beneficial in the management of many surgical, medical, critical care and recumbent patients too; there will always be indications for their use. It is clear, however, that there are a large number of associated risks and complications for veterinary professionals to be mindful of during the decision-mak-ing process, and the benefits of IDUC use should always outweigh the potential risks. Establishing robust practice hygiene and infection control/monitoring protocols is vital in combatting the problem of all types of HAIs, and additionally standard management protocols need to be devised and implemented relating to IDUC placement and management to reduce the risk of CAUTIs, which are a common HAI.

KEY POINTS

It is the responsibility of the veterinary surgeon to consider the risks and benefits of indwelling urinary catheters (IDUCs) for each individual patient before deciding on their final treatment plan.

Aseptic practice is essential in the placement and ongoing management of IDUCs.

Evidence-based standard operating procedures need to be created in veterinary practice for the placement and management of IDUCs, along with a practice-wide infection control/audit system.

All veterinary staff must be educated about the risks associated with hospital acquired infections (HAIs), and specifically catheter-associated urinary tract infections (CAUTIs).

References

Urinary catheters: indications for use and management

Abstract