Catheterisation may be short-term or long-term. Indications may include collecting a sterile urine sample, urinary tract obstruction, bladder decompression, urinary retention, urinary incompetence (e.g. patients with spinal cord injury) and to monitor urinary output (e.g. in critically ill patients or post-surgery).
Introduce yourself with your name and role, and confirm the patient’s name and date of birth. Explain the procedure, check the patient’s understanding and obtain consent. Always call for a chaperone. Wash your hands.
Ask the patient if they have any allergies, specifically to latex. Check whether the patient is currently in any pain.
Collect a procedure trolley, and clean the top surface using an alcohol surface disinfectant wipe. Next obtain a plastic tray and clean it in a similar manner. You will then need to collect:
- Disposable plastic apron.
- Two pairs of sterile gloves.
- Protective waterproof sheet.
- At least 10mL 0.9% sodium chloride (saline) solution for injection.
- 10ml sterile water, drawn into a syringe.
- 1% sterile lidocaine anaesthetic lubricating gel, drawn into a syringe.
- Urinary catheter (of appropriate type, size and length).
- Sterile catheter pack (containing cotton wool balls, gallipot (small pot), sterile gauze swabs, sterile fenestrated drapes, urine bowl).
- Sterile closed urinary drainage system (e.g. catheter bag).
- Urine collection bowl.
Check the expiry dates of the catheter, saline, sterile water and anaesthetic lubricating gel. Ensure that a clinical waste bin is nearby.
Wash your hands again and put on the disposable plastic apron. Open the catheter pack on top of the clean procedure trolley. Be sure to maintain sterility by only touching the outer packaging. Using aseptic non-touch technique, empty into the sterile field the catheter and the syringes containing lidocaine and sterile water.
When selecting a catheter consider patient gender, expected catheter duration period, previous catheter history and any allergies the patient may have (some catheters have a latex coating). In addition, select the appropriate:
- Length: Three lengths are available – short (23-26cm), standard (40-44cm) and paediatric (30cm). Short catheters are typically used in female patients, although standard catheters may be required for obese female patients. Only standard catheters should be used in male patients - the urethral tract is longer and use of a short catheter may result in trauma to the prostatic urethra.
- Balloon size: Three sizes are available – 5mL (for paediatric use), 10mL (for routine drainage) and 30mL (used post-operatively only).
- Charrier size: This is the circumference of the catheter. In female patients, a Charrier of 12-14 is usually used whereas in male patients you can use a Charrier of 12-16.
Ask the patient to lay supine, with their legs extended and slightly apart. The patient will need to remove their underwear.
Do not uncover the patient at this stage. Place the protective waterproof sheet beneath the patient’s buttocks.
Confirm (name and DOB), consent, check understanding, chaperone, behind the curtains, lie down on the couch (bed) and cover to preserve dignity.
Cleaning the area
Clean your hands and put on the sterile gloves. Place the cotton wool balls into the Gallipot (from the catheter pack) and pour over the 0.9% saline solution.
Expose the patient’s genitalia. Retract the foreskin (if present) and use a sterile swab in your non-dominant hand to hold the penis in place.
With your dominant hand, pick up a cotton wool ball. With a single stroke, clean part of the glans ensuring that you clean away from the urethral meatus. Repeat the process with fresh cotton until you are satisfied the glans has been cleaned. Next, open the sterile fenestrated drape and place the hole in the drape over the penis so it is surrounded. Dispose of the cotton wool balls in clinical waste. Position a sterile urine collection bowl below the penis, on top of the drape and between the patient’s legs.
Use a fresh sterile gauze swab in your non-dominant hand to hold the penis vertically. Next insert the syringe nozzle of the lubricating anaesthetic gel into the urethral meatus.
Slowly empty the syringe into the urethra. Whilst doing so, ensure that you continue to hold the penis in place to prevent the gel from escaping. Allow time for the anaesthetic to have effect (usually 3-4 minutes) before letting go of the penis.
Dispose of your gloves and don a new pair of sterile gloves.
Ensure that the distal end of the catheter is positioned in the collecting bowl to prevent urine spillage.
Carefully tear the plastic catheter wrapper along the perforated line to expose its tip. Recommence holding the penis vertically with your non-dominant hand using gauze. Warn the patient that you will now put in the catheter, and using your dominant hand, insert the catheter tip into the urethral meatus.
Advance the catheter slowly, whilst gradually retracting the wrapper. Continue until the catheter enters the bladder and urine flows, which, in males, usually occurs near to the catheter bifurcation point.
At this point you need to secure the catheter inside the bladder by inflating its balloon. Connect the syringe containing 10ml sterile water to the balloon port and gently inflate the catheter balloon. Whilst doing so, observe the patient closely and ask them to let you know if they experience any discomfort, as this may indicate that the catheter is not in the correct position.
After inflation, gently pull on the catheter until resistance is met. This ensures that the balloon is adequately inflated and sits securely at the entrance of the bladder.
Catheter bag attachment
Attach the catheter to a catheter bag, which should be positioned below the level of the bladder to ensure drainage. The bag should be secured in place on a catheter stand to prevent accidental catheter removal.
If necessary, clean the glans penis. Replace the retracted foreskin to prevent it from becoming trapped behind the glans penis (paraphimosis). Ensure the patient is comfortable and the surrounding area is clean and dry. Remove any equipment, thank the patient, and ask them to inform a member of staff if there is any leakage, pain or dislodgement of the catheter.
Remove your gloves and wash your hands. Record the procedure in the patient’s notes, documenting the date, time, procedure performed, indication for catheterisation, catheter size, local anaesthetic used, the amount and appearance of urine, any complications, the planned removal date and confirmation of consent and chaperone presence.
It is important to observe the appearance and amount of urine collected following catheterisation. Changes to either of these factors may indicate underlying disease.
A frothy appearance is typical of proteinuria (glomerulonephritis, diabetes mellitus), a red/pink appearance occurs in haematuria (urinary tract infection (UTI), urinary tract cancers, kidney stones), dark brown urine is typical of post-hepatic jaundice (as a result of gallstones or cancer of the pancreas head) and cloudy urine is also a sign of a UTI. In addition, be aware that urine colour may change with medication and can indicate hydration status.
In the average adult patient, urine output should be around 0.5-1ml/kg/hr.
- Oliguria is defined as <0.5ml/kg/hr (shock, AKI)
- Anuria is defined as <50mL/24hr (catheter blockage, acute kidney injury)
- Polyuria is defined as >3L/24h (diabetes mellitus, diabetes insipidus, excess IV fluids).