A patient may present to the ED after foley catheter placement for acute urinary retention (AUR) a few days ago and now requests catheter removal. Ideally this should be performed in the urologist’s office. However, occasionally patients cannot or do not follow up with the urologist in a timely manner and return to the ED expecting urethral catheter removal. A careful history and physical should be performed along with a consulting urologist. If the eventual decision is to remove the urethral catheter in the ED, what is important to know about a Trial of Void (TOV)?
EM Resident, SUNY Downstate Medical Center
Blog peer reviewer for ALiEM journal pilot project:
Javier Benítez, MD
What is a Trial of Void?
A Trial of Void, also referred to as Trial Without Catheter, involves removal of the urethral catheter and an assessment of the patient’s ability to spontaneously urinate. If successful, the patient may avoid or delay surgical intervention and possibly be managed medically.
- Remove the catheter, and encourage oral fluid intake.
- Measure the post-void residual (PVR) by re-catheterization or, more humanely, ultrasounding of the bladder. Also quantify the amount of urine spontaneously voided. 1,2
If the amount of urine voided is > 150 mL or the PVR is < 100 mL, there is a low recurrence of AUR and the TOV is considered successful. 3 PVR volumes up to 300 mL can be acceptable in patients who have chronic urinary retention. 4
Alternative technique: The infusion method
Because we don’t often have several hours in the ED for the bladder to refill after oral fluid intake, one might consider accelerating this process.
Infuse 300–500 mL of saline in the bladder prior to catheter removal. When compared to the standard method of oral fluid intake, it reduces time to discharge by almost 80 minutes as compared to the standard method. 5
How long after initial catheter placement can removal and Trial of Void take place?
No definitive guidelines exist. However, a survey of 6,074 patients with AUR by Fitzpatrick et al. 6 found that in patients whose catheter was removed at ≤ 3 days vs. ≥ 4 days, there was a lower frequency of:
- Urinary tract infection: 3.4% vs 7.2%
- Catheter obstruction: 0.8% vs 3.1%
- Urosepsis: 0.6% vs 1.2%
Traditional teaching and previous studies demonstrated that prolonging catheterization improves success of TOV attempt. 4 More recent studies have found either no improvement, or that TOV at ≤ 3 days was more successful than TOV done later.7 Regardless of when the catheter was removed, of utmost importance is the prior use of α-1 blockers, which several studies show improve the likelihood of successful TOV.6,8
- Consider a TOV as early as Day 3 if the patient has been taking α-1 blockers appropriately.
- When performing a TOV, consider the infusion method to speed up the time to decision and patient discharge.