Welcome to our next newsletter! This week we change pace a little, presenting a review of indications and nursing considerations for urinary catheterisation in male canine patients. Whether you work in an animal emergency centre, veteinary hospital or small clinic, urinary catheterisation is a fantastic skill to develop and have in your repertoire.
Urinary catheterisation is used in the pet emergency setting and critical care ward for diagnostic, treatment, and monitoring purposes. When used with care, indwelling urinary catheter placement is a valuable and useful procedure in any ward setting, including general practice.
That said, the clinician’s decision to use an indwelling urinary catheter in the critical patient is not one to be taken lightly. There are serious potential risks and complications associated with this procedure. Fortunately these can be significantly reduced by familiarity and compliance with placement and maintenance protocols.
There are many reasons why a patient may need a urinary catheter placed, including:
- maintenance of constant, controlled bladder drainage in recumbent, non-ambulatory and incontinent patients
- lower urinary tract support pre & post operatively
- relief of anatomic or functional obstruction
- accurate measurement of urine output
- collection of urine sample for analysis radiographic contrast procedures
Indications for urinary catheter placement are divided into those warranting a once off (or intermittent) placement, and those requiring an indwelling catheterisation.
Intermittent Urinary Catheterisation
Intermittent urinary catheterisation is commonly used to:
perform radiographic contrast procedures relieve an anatomical or functional obstruction causing urine retention obtain urine samples (n.b. bacterial and red cell contamination can occur in the first several mls of urine collected so it is important that this is not submitted for urinalysis or culture).
Indwelling Urinary Catheterisation
Indwelling urinary catheters are indicated for use in the critical patient for accurate determination of urinary output. They are also commonly used in:
- support of the lower urinary tract
- during and after surgery
- urine retention caused by neurogenic bladder dysfunction
- relief and maintenance of urinary obstructions.
Catheterisation should not make the situation worse, so careful consideration should be given prior to placement in the following circumstances:
- immunocompromised patients
- septic patients
- complete obstruction of urethra or bladder neck (or where catheterisation is not easily achieved without significant risk of urethral or bladder trauma)
- when the presence of a urethral catheter may adversely affect the outcome of surgical intervention.
Risks and Complications
The most common risk with the use of any urinary catheter is the risk of infection. As the catheter is inserted into the bladder it can also introduce bacteria.
Faulty placement technique, rough handling or use of excessive force when passing the catheter, and/or inadequate lubrication can cause urethral or bladder trauma. In severe cases it may lead to urethral strictures or even bladder rupture.
Prophylactic use of antibiotics is not recommended as they can cause selection of antibiotic resistant bacteria. If an infection is suspected, a sample from the distal tip of the urinary catheter should be taken and sent for a culture and sensitivity. This will allow for identification of bacteria and selection of antibiotics to which they are sensitive.
Types of Urinary Catheters for Veterinary Patients
Catheters are either self retaining or non-self retaining (the more commonly used of the two types).
Foley catheters are a balloon tipped catheter. When the balloon is inflated the catheter is anchored within the bladder. This negates the need for it to be sutured or stapled, however complications include damage to the bladder wall if balloon is overinflated or underinflated. Only sterile water should be used to inflate the balloon.
These are commonly straight urethral catheters with a single lumen and one or more openings at the distal end. These must be secured in place with tape, sutures or staples. At SARC we routinely use polyurethane feeding tubes in male dog urinary catheter placement.
They are soft, flexible and minimally irritating to mucosal surfaces. They are well suited for intermittent and indwelling catheter purposes and are available in a multitude of diameters and lengths.
Closed collection system
A sterile, closed collection system should be attached to all indwelling urinary catheters. This system consists of a sterile enclosed bag with attached tubing, which connects directly to the urinary catheter.
Manufactured varieties are commercially available through medical suppliers, and come pre-packed and sterile. Alternatively a sterile giving set attached to an empty drip bag is an adequate substitute, providing it is maintained in an aseptic manner.
Stay tuned for next week’s follow up article on urinary catheterisation. We will be looking at the practical aspects of choosing, placing and caring for these catheters.