From the Guidelines
Urodynamic studies, including filling cystometry and pressure flow studies, are the most effective investigations for determining detrusor function, as they provide direct measurements of bladder pressure and function. These studies can help diagnose detrusor overactivity or underactivity, which are common in men with lower urinary tract symptoms (LUTS) 1. According to the 2023 European Association of Urology guidelines, urodynamic techniques such as video urodynamics can provide additional anatomical and functional information, and can be used to associate bladder outlet obstruction (BOO) with detrusor overactivity 1. Other investigations, such as post-void residual measurement, bladder diaries, and pad tests, can provide valuable information about voiding patterns and bladder emptying efficiency, but are not a replacement for urodynamic studies in determining detrusor function. Some studies have proposed non-invasive tests to recognize BOO, but the diagnostic accuracy of these tests is limited by heterogeneity and a small number of studies 1. Key points to consider when investigating detrusor function include:
- Urodynamic studies are the gold standard for evaluating bladder function
- Filling cystometry and pressure flow studies are essential components of urodynamic studies
- Video urodynamics can provide additional information about bladder and urethral function
- Non-invasive tests have limited diagnostic accuracy and should be used selectively.
From the Research
Investigations for Detrusor Function
To determine detrusor muscle function, several investigations can be utilized:
- Urodynamic studies, including pressure-flow studies, which provide information about urethral resistance or obstruction and detrusor contraction or contractility 2
- Cystometry, which can reveal detrusor hyperreflexia and other abnormalities in bladder function 3, 4
- Electromyography (EMG), which can assess the activity of the external sphincter and diagnose detrusor-external sphincter dyssynergia (DESD) 3, 4
- Voiding cystourethrography (VCUG), which can confirm the location of obstruction and evaluate the lower urinary tract 5
- Uroflowmetry, which measures the flow rate of urine and can detect abnormalities in voiding patterns 4
Specific Parameters
Certain parameters can be measured during these investigations to assess detrusor function, including:
- Detrusor pressure at the point of maximum flow rate (P(det)Q(max)) 3
- Bladder outlet obstruction index (BOOI) 5
- Plateau detrusor contraction pattern, which is highly predictive of dysfunctional voiding/external sphincter nonrelaxation (DV/EUSD) 5
- Maximum cystometric capacity, compliance, and residual urine, which can be affected in patients with posterior urethral distraction (PUD) 4
- Bladder wall thickness (BWT), which may be increased in patients with detrusor overactivity (DO) 6