What is the procedure for completing a voiding trial (urinary retention assessment)?

From the Guidelines

A voiding trial should be conducted by first prescribing an oral alpha blocker prior to the trial, with the patient completing at least three days of medical therapy before attempting the trial without a catheter (TWOC), as this approach has been shown to improve outcomes in patients with acute urinary retention (AUR) related to benign prostatic hyperplasia (BPH) 1. To conduct a voiding trial, the following steps should be taken:

• Ensure the patient is adequately hydrated and explain the procedure to them
• Remove the catheter according to proper technique
• Ask the patient to drink 500-1000 mL of fluid over the next 2-4 hours
• Instruct the patient to urinate in a collection device when they feel the urge
• Measure the voided volume and perform a bladder scan within 30 minutes after voiding to check for residual urine A successful voiding trial typically requires the patient to void at least 200 mL with less than 100-150 mL of post-void residual urine. If the patient cannot void within 4-6 hours of catheter removal, has significant post-void residual (>150-200 mL), experiences severe discomfort, or shows signs of urinary retention, the trial is considered unsuccessful and recatheterization may be necessary, as indicated by the most recent guidelines 1. The use of alpha blockers, such as alfuzosin or tamsulosin, has been shown to improve outcomes in patients with AUR related to BPH, with pooled results showing successful TWOC with alfuzosin compared to placebo, 60% versus 39% 1. It is essential to inform patients who pass a successful TWOC for AUR from BPH that they remain at increased risk for recurrent urinary retention, as stated in the guidelines 1. The voiding trial assesses the bladder's ability to fill and empty properly, which is essential for normal urinary function after periods of catheterization that may temporarily affect bladder muscle tone and sensation. Key considerations for the voiding trial include:
• Patient hydration and understanding of the procedure
• Proper catheter removal technique
• Monitoring of voided volume and post-void residual urine
• Patient comfort and signs of urinary retention By following these steps and considering the latest guidelines, healthcare providers can effectively conduct a voiding trial and improve outcomes for patients with AUR related to BPH 1.

From the Research

Voiding Trial Procedure

The procedure for completing a voiding trial, also known as a urinary retention assessment, involves several steps:

• Backfilling the bladder with a specified amount of saline solution, typically 300 mL, or until the patient reports the urgency to void 2, 3
• Removing the catheter and prompting the patient to void immediately 2, 3
• Measuring the post-void residual (PVR) volume using sonographic bladder scan or catheterization 2, 3
• Evaluating the voided volume and PVR to determine the success of the voiding trial 2, 3

Criteria for Success

The criteria for a successful voiding trial vary, but common thresholds include:

• Voided volume of 200 mL or more, indicating a successful trial 2
• Voided volume of less than 100 mL, indicating an unsuccessful trial 2
• Voided volume between 100 and 199 mL, indicating an indeterminate trial and recommending further assessment 2

Techniques for Assessing Voiding Efficiency

Different techniques can be used to assess voiding efficiency, including:

• Backfill technique, which involves filling the bladder with saline solution before removing the catheter 3
• Auto-fill technique, which involves removing the catheter and allowing the bladder to fill spontaneously 3
• The backfill technique has been shown to be a better predictor of adequate postoperative bladder emptying than the auto-fill technique 3

Patient Removal of Urinary Catheters

Patient removal of urinary catheters at home has been shown to be non-inferior to office removal in terms of early postoperative urinary retention rates 4

• Patients who removed their catheters at home reported lower pain and difficulty, and higher satisfaction, compared to those who had their catheters removed in the office 4