A catheter is small and hollow tubing which is inserted into the body in order to remove and drain urine directly into a urinary bag for disposal. It can be inserted through the urethra or into a suprapubic cystostomy, which is a surgically created hole in the abdominal wall to the bladder. Catheters are required for patients who suffer from urinary incontinence or urinary retention, conditions which are usually a side effect of other serious medical illnesses (1).

Types of urinary catheters

Urinary catheters can be divided into three categories; intermittent, short term and long term.

• Intermittent catheters will be inserted and then removed immediately once the bladder has been drained. A doctor may advise the use of an intermittent catheter to obtain a sterile urine specimen or to check residual bladder volume in the absence of an ultrasound machine. Patients who use intermittent catheters at home to self-catheterise should continue to do so if they are in a hospital setting – however it is preferred they use a new catheter each time to decrease the risk of infection, whereas it is encouraged to reuse catheters in a home setting. Self-catheterisation is used not only to maintain bladder function by regularly emptying it but also in the management of urethral stricture conditions (2).

• Short term catheters will be left in-situ for up to seven days. They are preferred during the pre and post operative periods so that urinary output can be clearly monitored. Unless the patient has a latex allergy, latex based silicone coated catheters are commonly used as short term catheters. Otherwise catheters made entirely of silicone are also available (2).

• Long term catheters which can last up to three months are made entirely of silicone and are hydrogel coated. Certain patients may require catheterisation for the rest of their lives; therefore suprapubic catheterisation is preferred to offer patients comfort and ease. Long term catheters should be changed according to individual needs, although the longest they can be left in will be based on the manufacturer’s recommendations (2).

As many different types of catheters are available, individual patient needs should be carefully considered when selecting a catheter. Factors to consider involve (2);

• Reasoning for catheterisation
• Expected duration for catheterisation
• Whether urethral or suprapubic catheterisation will be used
• Catheter material and any patient allergies
• Catheter size – there is paediatric length, regular, and female (female is the shortest length)
• Balloon size – the smallest size of balloon will minimise the level of residual urine, reduce the chances of a bladder spasm and minimise potential damage to the bladder neck as a result of the balloon weight

Which conditions require catheters?

Urinary catheters can be beneficial for patients with many different conditions, however all patients will have the inability to empty their bladders.

Short term and intermittent catheters can be used by the following types of patients (3);

• Those who are undergoing surgery on their womb, ovaries, prostate glands or bowels. This is so that the bladder is emptied prior to surgeries and medical investigations.
• Pregnant women who have had an epidural anaesthetic and need to empty their bladders.

Long term indwelling catheters can be used by the following types of patients (3);

• Those who have suffered from a stroke or a spinal injury leading to paralysis
• Those who have multiple sclerosis, spina bifida or other conditions which can negatively affect the nerves which control the bladder
• Those who have chronic debilitating or terminal illnesses which can cause loss of mobility and self-awareness, resulting in the inability to independently use a toilet

Patients may also require catheters so that they can heal following a lower urinary tract surgery and to assist healing by keeping the perineal area dry. In some cases, a catheter can be used to administer medicine directly into the bladder, mainly during chemotherapy for bladder cancer (2).

Risks associated with urinary catheters

The main risk of using urinary catheters is that patients are more prone to urinary tract infections. However most infections can be easily treated with a course of antibiotics.

Proper sterilisation and infection control methods must be strictly adhered to both before and after the catheter insertion process. Healthcare professionals and patients must wash hands and the genital area thoroughly whenever handling the catheter, and patients are advised to drink plenty of fluids to prevent the development of infections (4).

Other, although less common, risks associated with catheterisation involve;

• Bladder spasms. These are a result of the bladder attempting to squeeze out the catheter balloon. Medication is available to reduce intensity and frequency of bladder spasms.
• Injury to the bladder or rectum due to incorrect insertion methods.
• Narrowing of the urethra due to repeated use of catheters and scar tissue development.

Sources:

1. Better Health
2. ANZUNS
3. Health Talk
4. Independent Living Centres Australia