Urinary incontinence

Urinary incontinence refers to the involuntary leakage of urine.

Urinary incontinence is common in women and incidence increases with advancing age. There are a number of subtypes:

• Stress incontinence: related to increased intra-abdominal pressure
• Urgency incontinence: related to an overactive bladder
• Mixed incontinence: a combination of the above two causes
• Overflow incontinence: secondary to ‘overflow’ in patients with urinary retention

This note focuses specifically on urinary incontinence in women and those with female pelvic organs.

It is estimated that 5-69% of females have urinary incontinence.

There is a wide range of incidence and prevalence estimates for urinary incontinence in women. This reflects the different ways of measuring disease, the spectrum of disease (where many cases have minor symptoms) and underreporting.

A cross-sectional postal study of females over the age of 21 by Cooper et al found 40% of respondents had urinary incontinence. 17% had sought medical attention and significant problems were described by 8.5%.

Stress, urgency and mixed are the most common causes of incontinence.

Stress incontinence

This refers to incontinence that occurs secondary to a rise in intra-abdominal pressure. This may be triggered by coughing, sneezing or exertion.

There are a number of factors that increase the risk of stress incontinence. Generally, they are factors that lead to a weakening of the pelvic floor muscles. These include:

• Age
• Pregnancy & vaginal delivery
• Constipation
• Obesity
• Family history

Urgency incontinence

Urgency incontinence is characterised by the urge to pass urine associated with involuntary leakage. It occurs secondary to an overactive bladder – a condition that may or may not be associated with urgency incontinence.

It appears to occur due to detrusor muscle overactivity that leads to involuntary contractions of the bladder. In the majority of cases it is idiopathic but it can occur secondary to neurological disorders.

Mixed incontinence

This refers to involuntary leakage of urine that is secondary to a mix of both stress and urgency incontinence.

Overflow incontinence

Overflow incontinence happens when someone is unable to completely empty their bladder with ‘overflow’ occurring when the bladder becomes very full or secondary to stress/urge elements. It can occur secondary to physical obstruction or underactivity of the detrusor muscle:

• Bladder outlet obstruction: refers to a physical blockage and compression of the urethra, this may result from a number of pathologies including prolapse and fibroids or following pelvic surgery.
• Detrusor underactivity: reduced or impaired contraction of the detrusor muscle can lead to retention and overflow leakage. This occurs with advancing age, in those with peripheral neuropathy, spinal cord pathologies (e.g. MS) and secondary to medications (e.g. antimuscarinics)

The assessment of urinary incontinence aims to identify the underlying type and any contributing pathological processes.

History and examination

A thorough history should help establish what type of incontinence a patient is experiencing. An examination should be completed. In particular, examine the abdomen for masses or a palpable bladder.

Following appropriate explanation, consent and with a chaperone present, perform a pelvic exam. Observe any evidence of prolapse, pelvic mass or fistula opening. Pelvic muscle tone can be tested during bimanual examination.

Bedside tests

• Urine dipstick +/- MSU: a urine dipstick should be completed and an MSU sent if there is evidence of infection (positive leucocytes and/or nitrites). If they have a positive dip and symptoms of UTI antibiotics can be commenced whilst awaiting the MSU. If it is positive for blood consider urology referral and follow the NICE guidance for urgent referral for suspected urological malignancy.
• Bladder scan: a post-void residual should be recorded (a bladder scan after the patient empties their bladder as best they can). This helps to identify patients with urinary retention and likely overflow incontinence.

Patient-based assessments

• Bladder diaries
• Quality of life assessments

Urodynamic testing

Urodynamic testing is not routinely required. However, NICE guidance 123 (2019) recommends multi-channel filling and voiding cystometry is arranged prior to surgery for stress incontinence in those who have any of:

• Urge-predominant mixed urinary incontinence or urinary incontinence in which the type is unclear
• Symptoms suggestive of voiding dysfunction
• Anterior or apical prolapse
• A history of previous surgery for stress urinary incontinence.

Cytometry is a urodynamic test that involves the insertion of a urinary catheter and the gradual filling of the bladder. A rectal probe is used at the same time to measure pressure as the bladder fills and then during voiding.

Management is guided by the type of urinary incontinence.

In patients with mixed incontinence, it should be targeted at the type that appears to most contribute to their symptoms but a cross-over of the treatment options may be used.

It is important to identify any possible underlying cause. NICE CKS advise referral if there is:

• A bladder that is palpable on abdominal or bimanual examination after voiding
• Voiding difficulty
• Persistent bladder or urethral pain (refer urgently if cancer is suspected)
• A pelvic mass that is clinically benign
• Associated faecal incontinence
• Suspected neurological disease
• A history of previous incontinence surgery, pelvic cancer surgery, or radiation therapy
• Recurrent urinary tract infection — for recurrent or persistent unexplained urinary tract infection in people aged 60 years and over, consider non-urgent referral for bladder cancer
• Suspected urogenital fistulae

A referral is also recommended when there is any suspicion of bladder cancer based on NICE referral guidelines.

There are a number of specific surgical interventions for patients with pelvic organ prolapse and urinary incontinence but that is not discussed here. Below we summarise some key aspects of management, for more detail see NICE guideline 123: Urinary incontinence and pelvic organ prolapse in women: management.

Stress incontinence

Lifestyle

Patients should be advised to have a consistent fluid intake of around 1.5-2 litres, avoiding either excess or insufficient amounts.

In patients who are overweight, help with healthy weight loss should be offered. Where relevant offer referral to smoking cessation services. Caffeine may be avoided particularly if the patient has mixed incontinence with an urge component.

Pelvic floor muscle training

A trial (at least 3 months) of supervised pelvic floor muscle training should be offered. Patients are taught techniques involving the contraction of pelvic muscles 8 times on 3 occasions throughout the day to strengthen the pelvic floor. Where it improves symptoms it should be continued.

Specialist care

Referral should be made to a urogynaecologist, gynaecologist, or urologist where conservative measures fail to adequately control symptoms.

Surgical techniques for stress urinary incontinence include:

• Colposuspension: this is an operation that may be completed open or laparoscopically and involves lifting the bladder neck upward with stitches placed to hold it in place.
• Autologous rectus fascial sling: a sling is made from the patient’s own fascia and is used to support the urethra and the pelvic floor muscles.

Other options include an intramural bulking agent or a retropubic mid-urethral mesh sling.

Duloxetine may be offered second-line in patients who do not want surgical management and are appropriately counselled on the adverse effects. It is a serotonin-norepinephrine reuptake inhibitor whose side effects include dry mouth, headache, dizziness, nausea, sexual dysfunction and a reported increased risk of suicide.

Urgency incontinence

Lifestyle

Patients should be advised to have a consistent fluid intake (around 1.5-2 litres), avoiding either excess or insufficient amounts. A trial without or with reduced caffeine should be advised. In patients who are overweight, help with healthy weight loss should be offered.

Bladder training

A trial (at least 6 weeks) of bladder training should be offered for women with urgency incontinence or mixed incontinence.

This therapy involves training the bladder to tolerate larger volumes of urine. Instead of going to pass urine as soon as you feel the need to go the patient is advised to hold it for gradually longer lengths of time.

Pharmacological therapy

Anticholinergic therapy may be used in patients with an overactive bladder as they help to reduce detrusor overactivity. Oxybutynin is typically used first-line. Side effects include dry mouth, constipation, urinary retention and confusion.

Overflow incontinence

All patients should be referred to a urogynaecologist, gynaecologist, or urologist depending on local services. If there is an obstructive cause, surgical intervention may be required.

Catheterisation (intermittent, indwelling or suprapubic) may be considered where the pathology cannot be corrected and the retention is leading to UTIs or renal impairment.

Urinary incontinence in women follow a highly variable course.

The prognosis depends on the underlying type of incontinence. A study by Waetjen et al of 2415 women found over six years that 52.9% had no change in the frequency of their symptoms, whilst 14.7% reported worsening and 32.4% reported improvement.