How to place and manage indwelling urinary catheters
Wednesday, June 1, 2011
Indwelling urinary catheters (IDUC) are regularly used in veterinary practice and serve many purposes. IDUC often enhance the care of a patient by preventing soiling and urine scalding, providing essential monitoring and overall comfort and care. It is a necessary skill of veterinary nurses to be able to place them and know how to manage them properly. They also need to understand why the catheter is required in their patients and what signs to look out for to provide the best care for their patient. This article will be addressing the reasons why IDUC are used, how to place one in a canine patient, how to manage them and what the potential complications could be.
Indwelling urinary catheters (IDUC) are often used in veterinary practice. Registered veterinary nurses (RVN) are primarily involved in the decision to catheterize their patients, and in the selection, placement and management of IDUC (Orpet and Welsh, 2011). IDUC are sometimes necessary during a patient's hospitalization when a patient requires assistance to urinate because of their condition, e.g. lower motor neurone syndrome, surgery, such as urethropexy, or because of iatrogenic causes, such as an epidural (Pomfret, 2009). As veterinary nurses continually strive for professionalism and improved patient care, it can be said that the placement and management of IDUC allows nurses to use their skills to provide the best care for their patients in terms of management and monitoring. This helps to support the use of nursing care plans by providing more accurate and knowledgeable feedback on the patient's physiological status (Aggleton and Chalmers, 2000). Nursing care plans are a fairly new development to the veterinary nursing profession and expand on standard hospital sheets providing a more holistic approach to nursing care and forcing RVNs to ask questions regarding their patients, such as is the animal able to urinate (Orpet and Welsh, 2011)?
Bladder care and management protocols may vary from practice to practice. In some, IDUC may not be regularly used, and may only be placed by the veterinary surgeon, for example placing a tom cat catheter to relieve urethral obstruction in a male cat suffering from feline lower urinary tract disease. However, other veterinary practices may regularly use IDUC to manage more complex patients and surgeries, for example recumbent spinal patients or patients following urinary tract surgery (Rawlings et al, 2002). Male dogs may require intermittent catheterization or IDUC placement to relieve urine retention, either through spinal injury or other causes, which will be discussed later. This is often performed by the veterinary nurse and can be done so in the conscious patient depending on the animal's temperament. Catheterization of the bitch is considered more difficult because of their anatomy. Cats too are notoriously more challenging and require sedation and veterinary assistance. Therefore this article will focus on how to place and manage IDUCs in the canine patient, considering the indications for placing a catheter, the complications that may occur, how to place and manage an IDUC and the choices of open vs. closed collection systems.
There are a number of reasons for urinary catheterization, these include:
To obtain an uncontaminated urine sample for culture and sensitivity (Lane and Cooper, 2003)
To empty the bladder prior to abdominal, vaginal and urethral surgery, or urinary tract study or when there is an obstruction and the patient is unable to urinate (Busch, 2006)
To introduce drugs or contrast agents for radiographic studies (Lane and Cooper, 2003)
To manage bladder drainage, in recumbent or incontinent patients, or those who have had urinary tract surgery to avoid overdistension of the bladder and provide optimum healing conditions (Busch, 2006)
To maintain a patent urethra or for hydropropulsion in obstructed patients (Lane and Cooper, 2003)
To monitor urine output (UOP) in patients with renal disease, or those who have had renal surgery, during anaesthesia to monitor renal perfusion and fluid therapy, or intensive care patients (Welsh, 2003)
To monitor and treat urinary tract infection (UTI) (Lane and Cooper, 2003)
To maintain constant, controlled bladder drainage when there is urinary retention due to nerve damage or epidural, or in the recumbent patient (Welsh, 2003)
To prevent urine leakage on to the sterile field during soft tissue surgery involving surrounding structures of the prepuce (Busch, 2006)
There are many complications that can arise during or after the placement of an IDUC. These complications should be considered before placing an IDUC in a patient and should be monitored for throughout its use. Good records relating to the IDUC and urine should be kept for each patient and the veterinary surgeon should be informed of any complications. Appropriate action should be taken if they occur, which will be further discussed, particularly in the case of UTI. There are a number of possible complications:
UTI is the most common complication and occurs when bacteria are introduced from the urethra during placement, following unsterile placement, IDUC, repeated catheterization, bladder trauma or in immunosuppressed patients (Bubenik and Hosgood, 2008)
Cystitis, which can be reactive or infective. It is seldom seen and often presents after repeated catheterization (Lane and Cooper, 2003)
Urethral or bladder trauma is more common in males as the ischial curve of the urethra is negogiated during placement. In bitches it is often caused by excess force being used when the catheter is advanced (Orpet and Welsh, 2011)
Step-by-step guide to IDUC placement in the dog
Lay the patient in lateral recumbency on a clean incontinence sheet with an assistant restraining the patient. Sedation may be deemed necessary at this stage if the animal is uncooperative (Lane and Cooper, 2003).
Wash hands and wear gloves.
Clip and vacuum the hair from the distal aspect of the prepuce and 2 inches around the insertion site including the ventral aspect of the abdomen (Smarick et al, 2004).
Extrude the penis from the prepuce and prepare the area (wipe end of penis and flush the prepuce five times) using dilute chlorhexidine (0.05%) (Sullivan et al, 2010).
Instill 1 ml of 2% lidocaine or 0.5–3 ml of sterile lidocaine jelly into the urethral opening under veterinary surgeon direction (Smarick et al, 2004).
Replace gloves with sterile gloves using the open gloving technique (Smarick et al, 2004).
Create a sterile field using a sterile barrier drape with a hole cut to access the penis.
Keeping the catheter as sterile as possible using the ‘no touch technique’, where a ‘feeder’ section is cut into the catheter packaging allowing the catheter to be gradually advanced into the bladder from within its sterile packaging thus improving asepsis, remove the catheter tip from the packaging and apply sterile lubricant. Then begin to insert the catheter into the urethral opening, advancing gently. The remaining part of the catheter should remain inside the sterile packaging as the catheter is gradually inserted to keep it as sterile as possible during placement. A guide wire/stylet may be needed at this stage if there is difficulty advancing the catheter (Orpet and Welsh, 2011).
Continue to advance the catheter until urine begins to flow back and placement in the bladder is confirmed. If there is no urine visible the catheter could be flushed or the process started again (Sullivan et al, 2010).
Attach the syringe adaptor/spigot and bung to the end of the catheter to prevent urine leakage (Smarick et al, 2004).
Fill the Foley balloon with sterile water to keep it in situ and gently withdraw the catheter until resistance is met to ensure the balloon is inflated and the catheter is secure (Sullivan et al, 2010).
Flush the IDUC with 5–10ml of sterile water and aspirate the same amount back (Smarick et al, 2004).
Drain the bladder, measure and record the amount or attach to a collection system (Orpet and Welsh, 2011).
Secure the catheter to the patient using a length of dressing tied around its abdomen or leg, or Surgifix around its abdomen, not too tightly (Orpet and Welsh, 2011).
Attach to urine collection bag if appropriate, position the bag lower than the patient and tape the tubing higher up, either to the patient's leg or kennel so that it does not pull on the catheter causing pain and discomfort or potentially removing it. The collection bag should be kept in a clean tray lined with a clean incontinence sheet (Smarick et al, 2004).
Ensure patient is wearing an Elizabethan collar (Orpet and Welsh, 2011) (Figure 1).
Failure to catheterize can happen in the bitch if the urethral orifice is passed. It can also occur in the male dog if there is extreme soft tissue swelling around the penis, for example road traffic accident patients (Lane and Cooper, 2003)
Patient resistance is a situation that often presents itself and is most common in bitches and cats (Lane and Cooper, 2003)
Blockage/obstruction of the IDUC can occur due to poor management or urine sediment (Lane and Cooper, 2003)
Self-mutilation/removal of the catheter is likely to happen and should be prevented by securing the IDUC to the patient and applying an Elizabethan collar (Orpet and Welsh, 2011)
How to place an IDUC
Equipment/consumables required for IDUC placement
It is important to have everything ready for IDUC placement before starting to undertake the procedure. It is also important to think about the appropriate collection system suitable for the patient, their temperament, condition, and future management before placing an IDUC, which will be discussed throughout this article. Placement requires:
Incontinence sheet to keep the area clean and absorb any urine leaks during placement
Catheter — silicone Foley of appropriate size (length and gauge) for the animal
Sterile water-based lubricant to aid catheter advancement
Diluted chlorhexidine solution or povidone iodine solution for skin preparation; if chlorhexidine is used the area must be rinsed with water after preparation due to its cytotoxic properties (Orpet and Welsh, 2011)
Sterile water for balloon inflation (amount required is stated on the catheter, e.g. 1.5 ml) to hold the catheter in place and for flushing the catheter post placement
Local anaesthetic, e.g. 2% lidocaine or lidocaine gel to help desensitize the prepuce or vestibule (Sullivan et al, 2010)
A guide wire/stylet may be necessary to add rigidity to flexible catheters during placement, especially useful in bitches (Orpet and Welsh, 2011)
Sterile syringe for bladder drainage and a measuring jug
Bung and spigot to seal the free end of the catheter (Orpet and Welsh, 2011)
A light source for IDUC placement in the bitch and a sterile speculum of appropriate size (Orpet and Welsh, 2011)
Sedation drugs may be required for IDUC placement in the bitch — seek the veterinary surgeon's advice and direction
Examination gloves, sterile gloves and sterile drape
Elizabethan collar to prevent patient interference (Lane and Cooper, 2003)
Dressing/Surgifix to secure the catheter to the patient (Figure 2.)
IDUC placement in the dog
IDUC placement in the dog is considered the easiest and most commonly performed by RVNs as it can often be done in the conscious patient, depending on the dog's temperament, and is generally less difficult to place than in bitches. Refer to the step-by-step guide and Figure 1.
IDUC placement in the bitch
IDUC placement in the bitch involves the same principles regarding preparation and sterility as with the dog, but the patient may require sedation; as the restraint position required for placement is less comfortable/tolerated, placement may be more time consuming and more difficult.
For placement the patient is restrained in dorsal recumbency with the hindlimbs flexed and drawn forward. A sterile speculum and light source is used to visualize the urethral opening, the tip of the catheter is then inserted into the urethral orifice between the vulva and cervix and advanced into the bladder. This can also be done ‘blind’ using the digital method — in which a finger locates the urethral orifice and guides the catheter into the urethra — but this often takes a lot of experience. Once the catheter is placed aseptically the balloon should be inflated, the catheter flushed, secured and an appropriate collection system selected as with IDUC placement in the dog.
How to manage an IDUC
IDUC should always be kept secure and should always be a ‘closed’ system. A closed system means that the catheter is not open to the outside air. Being open to the outside air can result in urine scalding as urine will continually flow from the catheter, and also increase the risk of bacterial infection due to bacterial migration (Bubenik and Hosgood, 2008). IDUC should, therefore, either be closed using a sterile bung and emptied periodically or connected to a sterile urinary collection bag (Figure 3). The urinary collection bag or the bladder should be emptied and the urine measured every 4 hours. The amount should be recorded and the UOP calculated (amount of urine divided by 4 (hours) divided by the patient's bodyweight = ___ml/kg/hr) (Orpet and Welsh, 2011). The minimum UOP = 1–2 ml/kg/hr. This information is important as it is a good indication of kidney function and hydration status (Orpet and Welsh, 2011).
The IDUC should be flushed with sterile water if the patency of the catheter is in question, such as a decrease in UOP; frequent flushing will increase the risk of introducing infection as the closed system is broken and exposed to the external environment (Orpet and Welsh, 2011). When the catheter is flushed the amount of water instilled should be noted so that it is not included in the total amount of urine which would lead to a false UOP reading.
Colour, odour and amount of urine should also be noted, as these things could indicate infection, dehydration, renal complications or fluid overload. If abnormalities are detected urine dipstick and specific gravity tests should be performed. In addition, an uncontaminated urine sample could be sent away to the laboratory for urine culture and sensitivity if an infection is suspected. A specific gravity less than 1.030 indicates inadequate renal tubular concentrating ability (Lane and Cooper, 2003). The urine dipstick should show a pH between 5–7 and no traces of protein, blood, glucose, ketones or bile in a normal urine sample. The colour should be clear, yellow and with a characteristic smell (Lane and Cooper, 2003). As well as the aseptic placement of IDUC, the insertion site must be kept clean. The vulvar or preputial area should be cleaned, flushed using dilute chlorhexidine solution and rinsed, the exposed portion of catheter wiped clean with an antiseptic solution and all urinary catheter connections kept tight, clean and resting in a tray lined with a clean incontinence sheet (Smarick et al, 2004) (Figure 4).
The dressing securing the catheter to the patient should also be changed regularly and a clean and correct collection system should be used. Hands should be washed and gloves worn whenever handling the catheter or urine collection system (Sullivan et al, 2010).
Antibiotics should be avoided as prophylaxis for UTI, as studies such as the one conducted by Smarick et al (2004) researching the incidence of catheter-associated UTI among dogs in an intensive care unit, have shown they can increase the risk of UTI, and when infections do occur they have a high degree of antibacterial resistance (Lane, 2009). Antibiotic therapy is not always avoidable, however, as most inpatients are receiving antibiotics for their condition or surgery that is unrelated to the IDUC (Smarick et al, 2004). If an infection is present the RVN should remove the catheter and send the catheter tip away to the laboratory for culture and sensitivity, the results will allow the correct treatment to be administered to the animal (Smarick et al, 2004). It is also important to consider that an IDUC may cause discomfort or irritation, which can lead to stress, prolonged healing and self mutilation, so analgesics may be necessary if the patient is not already being administered them for another condition (Siddle, 2003). A study by Bubenik and Hosgood (2008) suggests that IDUC should not be maintained for longer than 4–5 days as the risk of UTI increases with each day (1.5 times) despite the use of antibiotic therapy. Therefore, it is recommended by Orpet and Welsh (2011) that an IDUC is ideally left in situ for no more than 24 hours in order to further reduce the risk of UTI. If an IDUC is required for a longer period then the catheter should be removed and a new one replaced using an aseptic technique. The collection system should also be changed for a new, sterile one to help to reduce the risks of UTI. More importantly this helps veterinary nurses to recognize the patient's ability to voluntarily urinate and therefore no longer require an IDUC (Bubenik and Hosgood, 2008).
Open urinary collection system vs. closed urinary collection system
An open urinary collection system involves connecting the catheter to a sterile reservoir bag with a length of collection line so it is kept away from the patient. A closed urinary collection system is when the end of the catheter is sealed using a sterile bung (Figure 5).
In fact both of these systems can be classed as ‘closed” as neither of them allows the catheter to be open to the air. It is suggested that the closed system would increase the risk of nosocomial bacteriuria as the bung is periodically disconnected from the catheter for the bladder to be drained (Figure 3), exposing the system to the external environment (Sullivan et al, 2010).
This is also why flushing the catheter is only recommended if the UOP decreases or patency is questioned to avoid ‘opening’ the system too often. However, the open system means that the line does not need to be disconnected in order to collect the urine from the reservoir bag therefore decreasing the incidence of bacteriuria. In theory there are more connections in the line with this system that could be a site for potential bacterial migration and it may be necessary for the system to be disconnected from the catheter so that the catheter can be flushed.
Research by Sullivan and Campbell (2010) evaluating open versus closed urine collection systems and the development of nosocomial bacteriuria has suggested that the type of urine collection system (open vs. closed) is not linked to the possibility of developing nosocomial bacteriuria. Further study is required but the most significant factors to prevent UTI include aseptic catheter placement and maintenance, and minimizing the duration of catheterization (Sullivan et al, 2010).
The ability of RVNs to place and manage an IDUC is a valuable asset in caring for hospitalized patients as it allows accurate monitoring of UOP and prevents patients from soiling themselves and suffering urine scalds. When placed and managed in the correct manner, according to research, such as the work conducted by Sullivan and Campbell, an IDUC can enhance a patient's wellbeing, progress and recovery. It can be concluded that using an aseptic technique during placement and subsequent handling, and close monitoring, reduces the risk of complications such UTI. IDUC help RVNs to ensure that they provide the best care for their patients and exercise their knowledge and skills. It has become clear from recent studies into IDUC and UTI that further research into the placement and management of IDUC is required, a situation that as RVNs we can contribute to through evidence-based practice.