What are the instructions for a Trial Without Catheter (TWOC)?

Trial Without Catheter (TWOC) Instructions

Patients undergoing a Trial Without Catheter (TWOC) should receive an oral alpha blocker for at least three days prior to catheter removal, followed by monitoring for successful voiding with post-void residual measurements. 1

Pre-TWOC Preparation

Medication Protocol

• Prescribe an oral alpha blocker prior to TWOC for patients with urinary retention related to BPH 1
  • Options include alfuzosin, tamsulosin, or silodosin
  • Continue medication for at least 3 days before attempting TWOC 1
  • Alpha blockers significantly increase TWOC success rates (60.2% vs 38.1% with placebo) 2

Patient Selection Considerations

• Factors predicting TWOC success:
  • Age under 70 years 3
  • Prostate size less than 50 ml 3, 4
  • Lower intravesical prostatic protrusion (less than 8 mm) 4
  • Lower IPSS score (less than 16) 4
  • Lower residual urine volume at catheterization (less than 800 ml) 4

TWOC Procedure

Timing of Catheter Removal

• Optimal catheter duration: 3-7 days before removal 3
• Ensure patient has received at least 3 days of alpha blocker therapy before attempting TWOC 1
• Schedule the procedure early in the day to allow for monitoring 1

Environment and Monitoring

• Perform TWOC in a controlled environment with appropriate monitoring 5
• Have the patient in a comfortable position for voiding
• Ensure privacy during the procedure

Catheter Removal Process

1. Explain the procedure to the patient
2. Deflate the catheter balloon completely
3. Remove the catheter gently
4. Ask the patient to drink fluids and attempt to void naturally
5. Monitor for successful voiding within 4-6 hours

Post-Removal Assessment

• Measure post-void residual (PVR) volume after first void 1
  • PVR should be less than 100-200 ml for successful TWOC 1
  • Use bladder scanner or in-and-out catheterization to measure PVR
• Consider TWOC successful if patient voids satisfactorily without need for re-catheterization within 24 hours 2

Post-TWOC Management

Successful TWOC

• Continue alpha blocker therapy (optimal duration not established in evidence) 2
• Inform patient about increased risk of recurrent urinary retention despite successful TWOC 1
• Schedule follow-up appointment to assess ongoing voiding function
• Consider discontinuing indwelling catheter alternatives (e.g., intermittent catheterization) if voiding is satisfactory 1

Failed TWOC

• Re-catheterize if:
  • Unable to void within 6-8 hours
  • PVR > 200 ml
  • Significant discomfort or distress
• Consider longer-term management options:
  • Extended alpha blocker therapy with repeat TWOC
  • Surgical intervention for BPH
  • Intermittent catheterization program 1

Common Pitfalls and Caveats

• Failure to use alpha blockers: Pre-treatment with alpha blockers is essential for improving TWOC success rates 1, 2
• Inadequate duration of alpha blocker therapy: Ensure at least 3 days of treatment before TWOC 1
• Insufficient monitoring: Always measure post-void residual volume to confirm successful voiding 1
• Ignoring risk factors for failure: Consider patient age, prostate size, and initial retention volume when planning TWOC 3, 4
• Premature discontinuation of alpha blockers: Continue medication after successful TWOC to reduce recurrence risk 2

Remember that despite successful TWOC, patients remain at increased risk for recurrent urinary retention and should be counseled accordingly 1.