Urinary Incontinence Flashcards
1
Q
How does the bladder store urine?
A
- Sympathetic nervous system - HYPOGASTRIC nerve
-Relaxation of detrusor muscle (beta-adrenoceptors)
-Contraction of urethral smooth muscle + trigone (alpha-adrenoceptors) - Somatic nervous system - PUDENDAL nerve
-urethral striated muscle contraction
-inhibition of the detrusor reflex
2
Q
What occurs during the emptying phase of the bladder?
A
- Parasympathetic predominates - PELVIC nerve
-contraction of detrusor muscle
-relaxation of urethral muscle
3
Q
What is urinary continence?
A
- Brainstem micturition centre integrates urethral and detrusor function
- Cerebral cortex gives voluntary control by over-riding the
detrusor reflex
= holding in urine voluntarily until can go to the toilet
4
Q
Whats first step of investigating urinary incontinence?
A
- Differentiate between filling + emptying abnormality = Hx
5
Q
What are typical abnormalities of filling phase?
A
- Patients can urinate normally
- Patients can empty bladder normally
- Patients dribble urine between urinations
- Patients often have reduced bladder capacity
6
Q
What are Ddx for abnormalities of the filling phase?
A
- Involuntary contractions / urge incontinence
-cystitis of any underlying cause (bacterial, calculi, neoplasia) - Reduce pressure at the bladder neck =
-congenital / acquired USMI
-Intrapelvic/caudal bladder, hypoplastic bladder
-Bladder neck mass - Urine bypassing bladder / part of urethral sphincter muscle = ectopic ureters
7
Q
What are findings in abnormalities of the emptying phase?
A
- Distended bladder
- Constant dribbling of urine
- No / minimal normal urination of urine
8
Q
What are Ddx for abnormalities of the bladder emtying phase?
A
- Partial/complete urethral obstruction
- Chronic distension of bladder e.g.=
-Urethral obstruction (any cause)
-Pelvic trauma
-Intervertebral disc protrusion - Urethral detrusor dyssynergia
(Dyssynergia = contraction of urethral muscle at same time as detrusor contraction causes a functional urethral obstruction)
9
Q
What is urethral sphincter mechanism incompetence?
A
- Common condition in bitch uncommon in male dogs + rare in cats
- Commonest cause of incontinence in bitch
- Intermittent involuntary passage of urine when relaxing, recumbent, sleeping
- Dog leaves a patch of urine on bed, carpet …
- Acquired and congenital forms
10
Q
What is aetiology of USMI?
A
- Low urethral muscle tone
-reduces with aging, loss of oestrogen (neutering), obesity - Seen in combination with caudally positioned bladder
11
Q
What is acquired USMI?
A
- Commonest type of USMI, develops in “later” life
- Usually medium/large breeds =
-Dobermans, Boxers, Irish setters, Labradors - Usually seen in neutered females =
-Onset can be weeks, months/years after neutering
-Can be worsened by obesity
12
Q
What is congenital USMI?
A
- Uncommon but important form of USMI
- Juvenile bitches (present prior to 1st season) as incontinent puppies
- 50% resolve after 1st season (don’t neuter these bitches
until after 1st season) - Ectopic ureter is main ddx for this condition but dogs with ectopic ureter often also have congenital USMI
13
Q
How would you investigate urinary incontinence?
A
- Detailed Hx
- Clinical Exam
- Biochem + haematology
- Urinalysis
- Urine culture + sensitivity (cystocentesis)
- Observe urinating
- Imaging = US, plain + contrast radiographs, CT
- Cystoscopy
14
Q
How is USMI diagnosed?
A
- Hx + CS suggestive of USMI
- Rule out conditions causing PD + PU
- Rule out UTI + causes of cystitis
- Imaging
- Trial medical tx
15
Q
What is medical treatment of USMI?
A
- increase urethral smooth muscle tone =
-phenylpropanolamine / ephedrine
-estriol (only in neutered bitches)
-deslorelin implants - Reduce possible contributing factors
-weight loss if obese
-treat secondary UTI
