Introduction
Urinary catheterisation is one of the most commonly tested clinical skills in OSCEs. Examiners assess ANTT compliance, correct equipment selection, safe technique, patient communication, and recognition of complications.
💎 Clinical Pearl
Think through the procedure before touching anything. Arrange equipment in order of use. Talk to the patient throughout — catheterisation is an intimate procedure and continuous communication is expected on mark schemes.
Indications
| Indication | Example |
|---|---|
| Urinary retention | BPH, post-operative, neurogenic bladder |
| Urine output monitoring | ITU, major surgery, sepsis |
| Bladder irrigation | Post-TURP haematuria |
| Specimen collection | MSU not possible, confused patient |
| Drug instillation | Intravesical chemotherapy |
Contraindications
- Suspected urethral injury: blood at meatus, pelvic trauma, perineal bruising — call urology
- Known urethral stricture: attempt with guidance or consider suprapubic catheter
Equipment Checklist
- Catheterisation pack (sterile drape, bowl, gauze)
- Sterile gloves (correct size)
- Cleaning solution (normal saline or chlorhexidine)
- Catheter (correct size and type)
- 10 mL sterile water syringe (balloon inflation)
- Anaesthetic lubricating gel (instillagel — 1 tube male, 1 tube female)
- Drainage bag and stand
- Specimen pot if required
- Apron, alcohol gel
Catheter Selection
| Type | Use |
|---|---|
| Foley 2-way | Standard retention |
| 3-way Foley | Bladder irrigation (post-TURP) |
| Coude (curved) tip | BPH, urethral stricture |
| Size | Use |
|---|---|
| 12-14 Ch | Standard female |
| 14-16 Ch | Standard male |
| 16-18 Ch | Haematuria or clot retention |
🧠 Mnemonic
CATHED — Consent, ANTT setup, Type and size, History of prostate or stricture, Explain procedure, Drape and clean
Procedure: Male Catheterisation
- 1Introduce yourself, confirm identity, obtain verbal consent
- 2Ensure privacy and offer a chaperone
- 3Perform hand hygiene and don apron
- 4Open pack aseptically without contaminating the sterile field
- 5Don sterile gloves
- 6Place sterile drape with hole over the penis
- 7Hold penis with non-dominant hand (now your contaminated hand — never touch the sterile field again)
- 8Retract foreskin; clean glans with gauze from meatus outward using circular motions
- 9Apply instillagel to urethra; hold meatus closed for 3-5 minutes
- 10Hold penis at 90 degrees to abdomen to straighten the urethra
- 11Advance catheter until urine flows — advance a further 5 cm before inflating balloon
- 12Inflate balloon with 10 mL sterile water; withdraw gently until resistance is felt
- 13Connect to drainage bag
- 14Replace foreskin — failure to do so causes paraphimosis
- 15Document: catheter size, balloon volume, residual volume, urine appearance
⚠️ Red Flag
Never inflate the balloon before confirming urine is draining. Inflating the balloon in the urethra causes serious urethral injury.
Procedure: Female Catheterisation
- 1Steps 1-4 as above
- 2Position: supine, knees bent, hips abducted
- 3Identify the urethral meatus (between clitoris anteriorly and vaginal introitus posteriorly)
- 4Clean labia minora and meatus front to back; discard each gauze after use
- 5Insert catheter 5-8 cm until urine flows; inflate balloon; withdraw until resistance felt
- 6Connect drainage bag; secure catheter to thigh
Complications
| Complication | Prevention |
|---|---|
| Catheter-associated UTI (CAUTI) | Strict ANTT; remove catheter as soon as possible |
| Urethral trauma or false passage | Gentle insertion; seek urology if resistance |
| Paraphimosis | Always replace foreskin after male catheterisation |
| Balloon inflation in urethra | Only inflate after confirmed urine drainage |
| Blocked catheter | Flush with saline; consider 3-way if haematuria |
"What are the indications for urinary catheterisation?"
Main indications: acute urinary retention, monitoring urine output in critically ill or post-operative patients, bladder irrigation after urological surgery, and obtaining a sterile urine specimen when midstream urine is not possible. It may also be used for intravesical drug delivery.
"What is ANTT and why does it matter for catheterisation?"
Aseptic Non-Touch Technique (ANTT) is a standardised framework for performing invasive procedures safely. The core principle is identifying the key parts (catheter tip, inside of the drainage bag port, syringe tip) and never touching or contaminating them. ANTT compliance is the single most important factor in preventing catheter-associated UTI, which accounts for a significant proportion of hospital-acquired infections.
"What happens if the foreskin is not replaced after male catheterisation?"
Failure to replace the foreskin causes paraphimosis — the retracted foreskin forms a tight ring that impairs venous drainage, causing progressive oedema of the glans. The swollen glans then makes manual reduction progressively more difficult. Paraphimosis is a urological emergency: apply firm circumferential pressure to reduce oedema then attempt manual reduction. If unsuccessful, call urology urgently.
"What do you do if you meet resistance during male catheterisation?"
Gentle resistance at the external sphincter is normal — ask the patient to breathe in and relax. Do not force the catheter. If resistance persists, consider an enlarged prostate (use a coude tip catheter), urethral stricture, or sphincter spasm. If unable to pass the catheter, contact urology. Forced insertion risks creating a false passage.
Related guides: [Venepuncture and Cannulation OSCE](/blog/venepuncture-cannulation-osce) | [A&E Assessment OSCE](/blog/ae-assessment-osce) | [Prescribing Safety OSCE](/blog/prescribing-safety-osce)