About the Author 

Rick Rayome, RN, BSN joined Coloplast after 3 decades of Urology experience working with adults and children with and without neurologic disorders. He is a recognized expert in the assessment of voiding dysfunction by multi-channel urodynamics. Rick is an author and contributed to peer reviewed clinical nursing journals and textbooks. He has served as a speaker for SUNA and WOCN conferences and held leadership positions in both organizations. Rick is currently a Clinical Specialist and employee of Coloplast.

The function of the urinary bladder is to fill, store, and empty urine.  The bladder functions as both a reservoir and a pump.5   Bladder emptying is achieved by a complex coordination of muscle and nerve reflexes to achieve relaxation of the bladder outlet and sustained contraction of the bladder during voiding to forcefully pass urine through the urethra and out of the body.  Post void residual urine (PVR) can result due to bladder outlet obstruction (BOO), poorly initiated or sustained contractions of the detrusor muscle (DU), or a combination of both.1   Interestingly, the symptoms associated with BOO and DU are very similar.  In either case, patients often complain of poor urine flow with an intermittent stream, straining to void, increased risk of urinary tract infection (UTI), and symptoms of overflow incontinence.1,2,3,5   Urodynamics testing with voiding pressure studies are often utilized to distinguish failure to empty due to the bladder, the outlet, or both. 

Detrusor underactivity (DU) is the urodynamic definition for failure to empty the bladder due to insufficient bladder contraction.  The International Continence Society (ICS) defines DU as, “a contraction of reduced strength and/ or duration, resulting in prolonged bladder emptying and/ or failure to achieve complete bladder emptying within a normal time span”.4   A diagnosis of DU requires invasive testing, expensive equipment that may or may not be readily available, and healthcare providers with the expertise to conduct and interpret the studies.  Unfortunately, not every clinical setting has the equipment or expertise available to provide a definitive, urodynamic diagnosis of DU.  Underactive Bladder (UAB) is a clinical symptom definition that has been proposed to resolve this challenge with urodynamic diagnosis of DU.3    Healthcare providers should suspect UAB when the patient reports symptoms of decreased sensation of bladder filling, decreased urgency, reduced urinary frequency, and persistent increases in PVR over time.  In contrast, patients with acute BOO most often report increased sensory urgency to void, urge incontinence, increased frequency, and discomfort with bladder filling and voiding.5 

Epidemiological studies have shown that 48% of elderly men and 45% of elderly women experience difficult with emptying the bladder due to DU/ UAB.1     Researchers have also found DU/ UAB occurs in 9% - 28% of patients under 50 years of age.3    A large urodynamic study of South Korean patients over age 65 found 46.5% of men and 72.6% of women had urinary retention secondary to DU and typically coexisted with BOO.6    Clearly, bladder emptying due to weak detrusor contraction is not uncommon.  Unfortunately, there has been limited research of DU/ UAB when compared to the investigation of BOO and overactive bladder (OAB). 

Increasing age is a contributing factor in developing DU/ UAB symptoms.  However, any disease that may negatively impact bladder contraction strength, velocity, and duration can cause or exacerbate DU/ UAB.  Diabetes is a chronic systemic disease that can contribute to organ failure resulting in sensory and motor neuropathies that impact bladder function.  Diseases and injury to neural function such as spinal cord injury, cerebral stroke, peripheral neuropathy, Parkinson’s Disease, or Multiple Sclerosis can also cause bladder dysfunction and poor detrusor contraction.  In general, the causes of DU/ UAB are due to neurogenic, myogenic, or mixed factors.

To date, effective pharmacological and surgical options for treatment of DU/ UAB remain elusive.  Sacral nerve root modulation and electrical stimulation has provided moderate improvement for selective patients.  Complications such as recurrent urinary tract infection, urosepsis, bladder and renal calculi, and renal impairment are known outcomes of chronic PVR and voiding dysfunction.  To reduce the risk of complications associated with PVR, intermittent catheterization remains as the primary method of bladder management for patients with chronic urinary retention.7   IC combined with adequate clinical assessment, individualized IC product selection to meet the patient’s needs, appropriate patient education on IC use and, adherence to prescribed IC frequency contributes to mitigation of significant risks associated with chronic PVR and an improved quality of life for patients. 

As the population continues to age, DU/ UAB is gaining more interest in the medical community and there has been a recent increase in research and study by the medical community.  Nevertheless, DU/ UAB has a long way to go to catch up to our current knowledge and understanding of BOO and OAB. 

References 

  1. Lee H, Wang C, Yung-Shun J.  Detrusor underactivity in men with bladder outlet obstruction.  Biomedicines 2022; 10; 2954; 2-12.  DOI 10.3390/biomedicines10112954.
  2. Wang J, Ren, L, et al. Underactive bladder and detrusor underactivity: new advances and prospectives.  Int J Mol Sci.  2023, 24, 15517.  DOI 10.3390/ijms24215517
  3. Osman N, Esperto F, and Chapple C.  Detrusor underactivity and the underactive bladder:  A systematic review of preclinical and clinical studies.  Eur Uro. 2018; 74; 633-643.  DOI 10.1016/j.eururo.2018.07.037
  4. D’Ancona C, Haylen B, Oelke M, et al.  The International Continence Society (ICS) report on the terminology for adult male lower urinary tract and pelvic floor symptoms and dysfunction.  Neurourology and Urodynamics.  2019;1-45.  https://doi.org/10.1002/nau.23897
  5. Chang YH, Siu J, et al. Review of underactive bladder.  J Formosan Med Assoc. 2018. 117; 178-184. 
  6. Jeong SJ, Kim HJ, et al. Prevalence and clinical features of detrusor underactivity among elderly with lower urinary tract symptoms: a comparison between men and women.  Korean J Uro. 2012. 53(5), 342-8.
  7. Stoffel J, et al.  AUA white paper on nonneurogenic chronic urinary retention:  consensus definition, treatment algorithm, and outcome end points.  Journal of Urology 2017;198;153-160.  DOI 10.1016/j.juro.2017.01.075

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