From the Guidelines
To be successful with a foley voiding trial, the catheter should be removed within 24 hours after surgery in the majority of cases, and individualized in patients with high risk of retention, as recommended by the ERAS society 1. This approach is crucial in minimizing the risk of urinary tract infections and ensuring the patient's bladder function returns to normal as soon as possible. When preparing for a foley voiding trial, it is essential to:
- Explain the procedure to the patient and confirm they are medically stable
- Remove the catheter at an appropriate time of day, typically morning, when staff is available to monitor progress
- Encourage the patient to drink 1-2 liters of fluid over the next 4-6 hours to stimulate the bladder
- Instruct the patient to void normally when they feel the urge and measure each voided volume
- Monitor for symptoms of urinary retention such as discomfort, inability to void, or small, frequent voids
- Consider medications that may help, such as alpha-blockers like tamsulosin 0.4 mg daily for men with prostatic obstruction, started 2-3 days before the trial, as suggested by general medical knowledge. Success is generally defined as voiding volumes of at least 200 ml with post-void residual volumes less than 100-150 ml, measured by bladder scanner or in-and-out catheterization 1. If the patient cannot void within 6-8 hours or has significant post-void residual volumes, the trial has failed and the catheter should be reinserted. It is also important to note that the use of indwelling urethral catheters should be avoided due to the risk of urinary tract infections, and if used, they should be assessed daily and removed as soon as possible 1. Additionally, a voiding diary, pad test, and non-invasive uroflow may be useful in evaluating patients with neurogenic lower urinary tract dysfunction, as suggested by the AUA/SUFU guideline 1. However, the most recent and highest quality study, the ERAS society recommendation 1, should be prioritized when making a definitive recommendation.
From the Research
Successful Foley Voiding Trial
To be successful with a Foley voiding trial, several factors should be considered:
- The back fill technique, where the bladder is filled with 300 cc saline before the Foley catheter is removed, appears to be a better predictor of adequate postoperative bladder emptying than the auto fill technique 2.
- A void of two-thirds or greater of total bladder volume at void 2 of the 2 voids is considered successful voiding 2.
- The use of an ultrasound bladder scanner can be an alternative modality to catheterization for the measurement of post-void residual urine volume, with high correlation and specificity 3.
- There is no significant difference in catheter burden between women who use an indwelling Foley catheter and those who use clean intermittent self-catheterization for management of postoperative voiding dysfunction after pelvic reconstructive surgery 4.
Post-Void Residual Urine Volume Measurement
The measurement of post-void residual urine volume is crucial in determining the success of a Foley voiding trial:
- The gold standard assessment of post-void residual urine volume is bladder catheterization 3.
- Ultrasound bladder scanners can provide accurate measurements of post-void residual urine volume, with a high correlation with catheterization measurements 3.
- The optimal post-void residual volume at which intermittent catheterization should be recommended is not well-defined, and other measures such as bladder voiding efficiency or urodynamic parameters may be more relevant in guiding management decisions 5.