301 Urinary incontinence and UTIs Flashcards
What is nocturnal enuresis?
Involuntary urination happens at night while sleeping, after age when person should be able to control his or her bladder
What is urinary incontinence?
Urinary incontinence (UI) also known as involuntary urination is any uncontrolled leakage of urine
Sensation of full bladder does not wake child
What is nocturnal enuresis caused by?
Caused by over production of urine at night, exceeding capacity of bladder to hold
Causes of bedwetting
Insufficient secretion of antidiuretic hormone (ADH) at night
Bladder dysfunction
Impaired brain arousal
Vasopressin mechanism:
Stimuli for Vasopressin Release
Release Site
Effects of Vasopressin
Overall Effect
- Hyperosmolarity, angiotensin II, decreased atrial receptor firing & sympathetic stimulation
- Posterior Pituitary
- V₁ Receptors (Blood Vessels): Constriction → Increased Systemic Vascular Resistance, V₂ Receptors (Kidneys): Fluid reabsorption → Increased Blood Volume
- Increased Arterial Pressure
ADH hormone (vasopressin) released by and acts on?
Pituitary gland
Acts on V2 receptors in distal kidney tubule to increase water reabsorption
Diabetes insipidus
ADH is reduced or absent, lack of sensitivity, leading to production of large volumes of dilute urine
Risk factors of bedwetting
Bedwetting family history
Male gender (2:1 male to female ratio)
Delay in attaining bladder control
Obesity
Psychological/behavioural disorders, such as ADHD, autism spectrum disorder & anxiety, depressive & conduct disorders
Underlying causes of bedwetting
Constipation
Diabetes
UTIs - if symptoms are recent
Behavioural or emotional problems
Family problems
Types of bedwetting
- Primary bedwetting without daytime symptoms - re-assure & provide non-pharmacological/pharmacological management
- Primary bedwetting with daytime symptoms - refer to specialist teams
- Secondary bedwetting - identify underlying cause, especially if child has been dry at night for 6 months
What is desmopressin?
Analogue of ADH and selective to V2 receptors in kidneys
How does desmopressin work?
Reduces amount of urine body produces at night; this mimics action of body’s own naturally occurring ADH
Management of nocturnal enuresis
Avoid blame and reassure parents
Bedwetting common in children under 5
Give advice on:
Diet and fluid intake
Toileting patterns
Lifting and waking
Positive reward systems
Enuresis alarms
1st line
High long-term success rate
Recommended for children 7+
Can be used younger but based on maturity & motivation
Desmopressin onset and short term improvement
Provides rapid onset in improvement or when short-term improvement is required
Start low & titrate up on response
Continue 3 months then stop for 1 week to check dryness
What should be cautioned with desmopressin?
Due to fluid retention, reduce fluid intake as blood becomes dilute and can cause hyponatraemia
Reduce fluids 1 hour before medication and 8 hours after
Patient and carer advice for desmopressin and hyponatraemic convulsions
Patients being treated for primary nocturnal enuresis should be warned to avoid fluid overload (including during swimming)
Stop taking desmopressin during an episode of vomiting or diarrhoea (until fluid balance normal)
* Patients being treated for primary nocturnal enuresis should be warned to avoid fluid overload (including during swimming)
Stop taking desmopressin during an episode of vomiting or diarrhoea (until fluid balance normal)
Imipramine
TCA
Last-line and used only when everything else failed
How does imipramine work?
Combination of increasing bladder activity (anticholinergic effects), improving arousal from sleep and enhancing bladder sphincter control (smooth muscle tone)
When should you consider imipramine?
Children and young people with bedwetting who have not responded to all other treatments & have been assessed by healthcare professional with expertise in management of bedwetting that has not responded to alarm and/or desmopressin
Why is imipramine and antimuscarinics often discontinued?
Side effects
Role of autonomic NS on bladder control
Parasympathetic - contract bladder
Sympathetic - relax bladder
Bladder control mechanism:
Bladder muscle (detrusor)
Bladder neck
- M₃ Receptors (Cholinergic - ACh): Contraction
β₃ Receptors (Adrenergic - NA): Relaxation - M₃ Receptors (Cholinergic - ACh): Relaxation
α₁L Receptors (Adrenergic - NA): Contraction
Types of incontinence:
Stress urinary
Result of weakening/damage to muscles used to prevent urination, such as pelvic floor muscles & urethral sphincter, when physical activity or movement puts pressure on bladder
Types of incontinence:
Urgency urinary
Result of overactivity of detrusor muscles, controls bladder resulting in intense, sudden urge to urinate, associated with overactive bladder syndrome
Types of incontinence:
Mixed urinary
Combination of both stress and urge of incontinence which results in patients experiencing symptoms of both types
Types of incontinence:
Overflow
Caused by obstruction or blockage in bladder, preventing it from emptying fully
Drug induced incontinence
Alpha-1, adrenoceptor antagonists (alfuzosin, doxazosin, tamsulosin)
Antipsychotics (chlorpromazine & haloperidol)
Anticholinergics - (causes retention so can cause ‘overflow’)
Anti-parkinsonism drugs
Antidepressants
BZDs
Beta blockers
Diuretics
HRT