From the Guidelines
Urinary retention is considered when the postvoid residual urine volume is greater than 100 mL, as recommended by the American Heart Association 1.
Definition and Diagnosis
Urinary retention is typically diagnosed when there is more than 100-150 milliliters of urine remaining in the bladder after voiding, as measured by a post-void residual (PVR) test. However, the specific threshold can vary depending on clinical context.
- A PVR volume under 50 ml is considered normal
- 50-100 ml is borderline
- Over 100-150 ml indicates retention, as suggested by the American Heart Association 1.
Clinical Context
For acute urinary retention, the bladder may hold 500-1000 ml or more, causing significant pain and discomfort.
- Chronic retention may involve residual volumes of 300-500 ml without pain due to gradual bladder stretching.
Importance of Measurement
These measurements are important because retained urine can lead to urinary tract infections, bladder damage, or kidney problems if left untreated.
- Urinary retention can be diagnosed using ultrasound, catheterization, or specialized bladder scanning devices.
Treatment and Evaluation
If you experience difficulty emptying your bladder completely, frequent urination, weak urine stream, or abdominal discomfort, consult a healthcare provider for proper evaluation and treatment, which may include medications like alpha-blockers, intermittent catheterization, or addressing underlying causes, as recommended by the American Heart Association 1.
- Intermittent catheterization should occur every 4 to 6 hours to prevent filling of the bladder beyond 500 mL and to stimulate normal physiological filling and emptying, as suggested by the American Heart Association 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Urinalysis Retention Definition
- The American Urological Association recommends that chronic urinary retention be defined as a postvoid residual (PVR) volume greater than 300 mL measured on two separate occasions and persisting for at least six months 2.
- There is no consensus regarding a PVR-based definition for acute urinary retention 2.
Postvoid Residual (PVR) Volume
- A PVR volume greater than 300 mL is considered indicative of chronic urinary retention 2.
- The measurement of PVR volume is an important diagnostic test in the evaluation of urinary retention 2.
Management of Urinary Retention
- Initial management of urinary retention involves assessment of urethral patency with prompt and complete bladder decompression by catheterization 2.
- Alpha blockers, such as tamsulosin, can increase the success rate of trial without catheter (TWOC) after an episode of acute urinary retention 3, 4, 5, 6.