Types of material used for urethral and suprapubic catheters

• Purpose of catheterisation
• Length of time catheter to be in situ
• Latex sensitivity (even if it is latex coated) document latex allergies in patient's records.
• Complications e.g. blockage, infection.

For routine drainage of clear urine select a catheter with a balloon filling volume of 5-10 ml maximum.

• Using a larger balloon infill means that the balloon surface comes in contact with the bladder wall.
• The greater the balloon size, the higher the balloon sits inside the bladder, which means the catheter tip can irritate the trigone area. This simulates the bladder muscle, which can cause spasm, bypassing, haematuria, and possible erosion of the bladder wall³.
• A 30ml volume balloon can be used on patients following urological surgery or for female patients with an incompetent bladder neck following discussion with medical staff or continence advisors.
• Under-inflation and over inflation of balloons can cause problems including distorting the tip of the catheter and occlude the drainage eye. Adhere to manufacturer's guidance on balloon capacity.

Catheter size is measured in French gauge; 1 CH indicates an external tube diameter of the catheter of 0.33 mm. Size 12-16 CH for patients with clear urine, smaller gauge catheters with a 10ml balloon minimise urethral trauma, mucosal irritation and residual urine in the bladder. These are all factors that predispose to catheter associated urinary tract infection (CAUTI)¹¹.

To maintain sterility, catheters must be stored in such a way as to protect the outer wrapping. Storing catheters in drawers or wrapped in elastic bands can damage the packaging, compromise sterility and compress the drainage channels. Catheters may also be damaged by heat and ultra-violet light and therefore should be stored on a shelf away from direct sunlight and radiators, within the packaging supplied by the manufacturer. Expiry date should always be checked before use⁶.

The maintenance of a closed drainage system is the single most important means of preventing infection in catheterised patients.

Note: Inpatients’ drainage systems should be changed as soon as possible to a leg bag to reduce infection and prevent trauma.

If patients are experiencing signs of a symptomatic CAUTI

Although all bags are fitted with a needle free sampling port on the drainage tube current evidence based practice advises to change the catheter and obtain a specimen of urine on insertion of new catheter and sent to lab in a red topped bottle.

Collection of a catheter specimen of urine

1. All bags should be fitted with a needle free sampling port on the drainage tube to allow the aseptic collection of catheter specimens of urine.
2. Decontaminate hands as per the WHO 5 moments for hand hygiene.
3. Wear non sterile gloves and plastic apron.
4. Clean sampling port with 70% isopropyl alcohol.
5. Allow 30 seconds for alcohol to dry.
6. Insert a sterile syringe into the needle free port to obtain the specimen.
7. If required empty the bag directly into a disposable receptacle without contaminating the tap^1,4.
8. Ensure drainage tap is dried at the end of procedure.
9. Remove PPE and decontaminate hands as per the WHO 5 moments for hand hygiene.
10. Dispose all equipment as per waste management policy.

Like catheters the drainage bag should be chosen to meet the needs of the individual patient. Consideration of type of tap used on bags depends on patient’s dexterity and choice. A catheter fixation device should be used for all patients with long term catheters¹².

When a leg bag is used it is desirable that it is connected overnight to a non-drainable bag.

The urine collection bag must be kept below the level of the bladder to prevent the backflow of urine into the bladder with the exception of the belly bag.

• The bag should be securely supported to prevent pulling on the catheter by using straps, pouches or holsters.
• A suitable stand should be used to ensure there is no traction on the drainage system when the patient is in bed.
• Patients with a drainable bag should always ensure that the outlet tap does not touch the floor and also ensure when draining the bag the tap does not contact the container¹³.
• Document clearly in the care plan when catheter bags and valves require to be changed. It may also be helpful to document the change date on the drainage bag. Drainage bags and valves should be changed every 5–7 days, unless damaged, discoloured or odorous.
• Empty the urine drainage bag when 2/3 full to maintain urine flow and prevent reflux.

Catheter valves allow drainage of urine without the attachment of a drainage bag. The catheter valve must be released 3 hourly to prevent over-distension of the bladder. Catheter valves are now available on prescription and are suitable for most patients following long term catheterisation and should be considered first line. Documentation should demonstrate this consideration and reasons for not using a valve should be recorded in the patient’s catheter history notes.

Inclusion criteria

• have good manual dexterity
• are cognitively aware
• have adequate bladder capacity (can store urine for 3-4hrs)
• patient choice
• patient compliance.

Exclusion criteria¹⁴

• post radical prostatectomy
• small capacity bladder
• overactive bladder
• ureteric reflux
• renal impairment.

Remember: Always have a spare catheter available when performing a catheterisation. Always follow the principles of safer handling as per Moving and Handling Guidelines whilst catheterising.