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Stress urinary incontinence in women: an overview

Marie Riding
RN DipHE
Continence Adviser
Oxfordshire Continence Advisory Service
Witney Community Hospital
Oxford
E:marie.riding@swoxon-pct.nhs.uk

Urinary incontinence (UI) is defined by the International Continence Society as "an involuntary loss of urine that is objectively shown and a social and hygienic problem".(1) It is an increasingly common condition, and in the UK alone there are between 2.5 and 4 million people with incontinence,(2) with an associated cost in the region of £750,000 per year to primary care trusts.(3)
Although incontinence is not essentially a life-threatening condition, the symptoms it causes can have a hugely devastating effect on the quality of life of the sufferer, their family, friends and carers. Feelings of embarrassment, anger, guilt and inconvenience are commonly expressed,(3,4) and if left untreated may lead to isolation, sexual dysfunction and potential loss of independence.(5)
Despite major advances in the treatments available to treat UI, the problem remains underreported due to embarrassment, stigma, lack of information and misconceptions of treatments available (see Table 1). In a study carried out by Button et al, 61% of their sample had not spoken to any healthcare professional about their incontinence.(7) However, it is estimated that in up to 70% of cases urinary symptoms can be improved or cured following appropriate treatment.(2)

[[NIP22_table1_42]]
 
Stress urinary incontinence
The most common type of incontinence in women in the UK is stress urinary incontinence (SUI), affecting in excess of 40% of women with reported UI.(8) Urge ­incontinence (overactive bladder) or a mixed condition of both urge incontinence and SUI is also common in women.(3)
The International Continence Society defines SUI as "the involuntary loss of urine when the intravesical pressure exceeds the maximum urethral closure pressure in the absence of detrusor activity".(3,9) The presenting symptoms of SUI, urge incontinence and mixed incontinence are shown in Table 2.

[[NIP22_table2_43]]

Causes of SUI
There are currently two known causes of SUI: anatomical defects due to bladder neck/urethral hypermobility, and/or neuromuscular defects resulting in intrinsic sphincter deficiency.(10) Continence is maintained when the urethral closure pressure is greater than the pressure inside the bladder (intravesical pressure). In people with SUI, when doing activities that may cause an increase in abdominal pressure (see Table 2), the pressure is transmitted to the bladder but not completely to the bladder neck or urethra, thus causing a temporary override of the urethral closure pressure by the intra-vesical pressure, resulting in a leakage of urine during the episode of raised abdominal pressure.(3,10)

Risk factors associated with SUI
In a review of the literature surrounding pelvic floor dysfunction carried out by Davis and Kumar,(5) the most commonly cited risk factors in the development of SUI are:

  • Pregnancy, obstetric trauma and multiparity.
  • Menopausal status and ageing.
  • Previous pelvic surgery.
  • Coexisting medical conditions such as abnormal connective tissue disorders.
  • Race and ethnicity.
  • Lifestyle/occupational factors that chronically increase intra-abdominal pressure, such as obesity, smoking, chronic respiratory disorders, high-impact exercise and strenuous exertion.
  • Defecatory disorders, such as constipation and rectocele.

Identifying women with SUI
The following trigger questions can be asked during routine checkups such as cervical smear screening, well-women clinics, antenatal classes and pre- and postnatal assessments,(11) or during admission consultations within the hospital setting:

  • Do you ever leak urine? - indicative of UI.
  • Does leakage occur when you cough, sneeze, run or jump? - indicative of SUI.
  • Do you ever need to pass urine more than once at night? - indicative of mixed, urge or other ­incontinence.
  • Do you ever feel a strong urge to pass urine? - indicative of mixed, urge or other ­incontinence.
  • Do you think you visit the toilet frequently? - indicative of mixed, urge or other incontinence.

Positive answers to any of the questions would indicate a degree of urinary dysfunction, and further assessment and consultation is required to determine the most appropriate treatment for the woman, taking into account the type of incontinence she is experiencing, the impact on her quality of life and her wishes.

Pelvic floor muscle exercises
Pelvic floor muscle exercises (PFMEs) remain the first-line therapy for women with SUI. The aim of the exercises is to help restore strength, power and function to the pelvic floor muscles. PFMEs have also been demonstrated to be useful in the treatment of urge incontinence.(12) For PFMEs to be effective a concordant agreement must be arrived at, as the exercises require motivation and determination on the part of the woman, to achieve improvement or cure.
The effectiveness of the exercises can be further determined by the ability of the woman to contract her pelvic floor muscles voluntarily. This requires an intact central nervous system. Vaginal assessment and/or biofeedback is a useful and accurate way of establishing the presence and efficiency of pelvic floor muscle activity during voluntary contraction. However, if vaginal assessment is not possible then visual observation of an inward movement of the perineum denotes a reasonable contraction.(12) If no muscle activity is noted during examination, then referral to a continence adviser or women's health specialist physiotherapist would be advisable.
Each woman will have differing exercise abilities; therefore an individualised exercise regimen is essential for success and adherence. Box 1 details the process of PFMEs further.

[[NIP22_box1_43]]

Other treatments available

Weighted vaginal exercise cones
These can be useful for biofeedback purposes and as an adjunct to regular PFMEs by aiding passive and active pelvic floor muscle contraction.(4) It is advisable that professional advice is sought by the woman to ensure that she is using the cones correctly and effectively.

Electromuscular stimulation
For the woman who is unable to voluntarily contract her pelvic floor muscles, treatment with electromuscular stimulation should be the next step.(3) The aim of electromuscular stimulation is to increase muscle strength by stimulating pelvic floor muscle contraction using electrical impulses delivered directly to the muscle tissues via electrodes placed in either the vagina or anus. Either a women's health specialist physiotherapist or a continence adviser can undertake this treatment.

Vaginal ring pessary
This is a device that is placed inside the vagina to provide support and increase the pressure to the neck of the bladder.(4,11) In effect it provides a "buttress" to the bladder neck during activities that may elicit SUI, thus preventing leakage. In some instances women may find that a vaginal tampon can also help, but caution needs to be exercised when recommending this owing to the associated risks of tampon use.
 
Oestrogen therapy
Inadequate oestrogen levels have been linked with impaired maintenance of the watertight seal provided by the natural convolutions of the urethra and atrophic vaginitis.(3) Topical oestrogen cream or hormone replacement therapy can be used to replace the ­deficient oestrogen levels for some women, thus increasing ­vaginal comfort and reducing severity of leakage.

Pharmacological options
Duloxetine is a newly available drug treatment for women with mild-to-moderate SUI. The pharmacological effect is to inhibit the reuptake of noradrenaline and serotonin, enhancing urethral sphincter contractility during bladder filling, thus preventing leakage.(10,11) Clinical studies have been encouraging and have concluded that duloxetine could be useful either in conjunction with PFMEs or as a standalone treatment if the woman is unable to carry out PFMEs.

Surgery
For women who do not respond to the more conservative treatments mentioned above, or for those who want definitive treatment, then surgery may be an appropriate option. Surgical procedures include Burch colposuspension, tension-free vaginal tape (TVT), periurethral bulking injections (collagen) and sling procedures.

Conclusion
SUI is now more easily treatable than ever, but it is also preventable in some instances. Nurses within primary care and acute settings are ideally placed to identify women with SUI and commence assessment and treatment, but moreover, nurses are ideally placed to provide health education to help women prevent SUI in the first place.
Pharmacological advances are a welcome adjunct to PFMEs and offer an alternative option for women who are unable to carry out exercises effectively. However, there is a risk that "a pill" may become an easy option for treatment in some cases, creating a possible financial burden to the NHS. Conversely, PFMEs are free and if done effectively are completely without risk to the individual.
Further work would be welcomed into the prevention of SUI - after all, prevention is better than cure.

References

  1. Abrams P, et al. Standardisation of terminology of the lower urinary tract function. Neurourol Urodyn 1988;7:403-27.
  2. Royal College of Physicians. Incontinence - causes, management and provision of services. London: RCP; 1995.
  3. Getliffe K, Dolman M, editors. Promoting continence: a clinical research resource. 2nd ed. London: Baillière Tindall; 2003.
  4. Thakar R, Stanton S. Regular review: management of urinary incontinence in women. BMJ 2000;321:1326-31.
  5. Davis K, Kumar D. Pelvic floor dysfunction: a conceptual framework for collaborative patient-centered care. J Adv Nurs 2003;43:555-68.
  6. Shaw C. The epidemiology and impact of stress urinary incontinence in women. SUI review. Newsletter produced by Eli Lilly/Boehringer Ingelheim; 2004.
  7. Button D, et al. Consensus guidelines for the promotion and management of continence by primary health care teams: development, implementation and evaluation. J Adv Nurs 1998;27:91-9.
  8. Hunskaar S, et al. Prevalence of stress urinary incontinence in women in four European countries. Abstract. Proceedings of the International Continence Society 32nd meeting. Heidelberg; August 2002. 257:166.
  9. Abrams P, et al. Incontinence: 2nd International Consultation on Incontinence. Paris; 1-3 July 2001. 205-6.
  10. Abrams P, Artibani W. Understanding stress urinary incontinence. Belgium: Ismar Healthcare; 2004.
  11. Bardsley A. Key trends in the management and treatment of stress urinary incontinence. Prof Nurse 2004;19(10):30-2.
  12. Haslam J. Pelvic floor muscle ­exercises. Nurs Times 2000;96(42)