Gynecology - Urine anatomy & physiology + Urinary incontinence

Question 1

What type of receptors does a women have in her detrusor muscle?/bladder dome - And what is the effect?

Answer 1

1. Muscarinic receptors 2 (80%) - contract bladder when activated
   2.Muscarinic receptors 3 (20%) - contract bladder when activated
   => Activated by acetylcholine (parasympathetic)
2. B-adrenergic receptors - relaxes the detrusor-mucle -> bladder becomes more compliant (favourable if you want to retain urine)
   => Activated by Nor/Epinephrine (sympathetic)

Question 2

Bladder neck and urethra are innervated by which type of receptors? - And effect?

Answer 2

Alpha (A) - receptors

When these are activated, they constrict -> This also favoures urinary retention (klemmer igjen urinrøret).

Question 3

What kind of effect will activation of alpha- and beta-receptors in the bladder in regards to pressure?

Answer 3

Increases the pressure gradient -> lower pressure in the bladder, higher pressure in urethra -> favours retention. (DECR. Intra vesicular pressura, INCR. intra-uretral pressure)

Question 4

What is the pressure in the bladder when you urinate?

Answer 4

Low pressure in uretra, high pressure in the bladder

Question 5

What kind of receptors activated the detrusor muscle?

Answer 5

The muscarinic receptors. These contract the detrusor muscle(raises the intravesicular pressure, favoures urination)

Question 6

What receptors are along the external urethral sphincter? And the effect?

Answer 6

Nicotinic receptors. Part of your somatic nervous system(voluntary), they are activated by Acethylcholine. Will cause constriction of the external urethral sphincter.(when you dont want to pee)

Question 7

Useful tool to diagnose type of urinary incontinence?

Answer 7

Voiding diary

Question 8

What is the normal volume of “natural” urinary urgency?

Answer 8

Around 400ml

Question 9

If a women has to urinate and passes only 100ml, this is called?

Answer 9

Urinary urgency

Question 10

What is the normal post-voidal urinary volume?

Answer 10

Around 50ml

Question 11

If a women urinates, and the bladder-scan post-voiding shows 150ml, this is called?

Answer 11

Urinary retention

Question 12

3 drugs used in urinary incontinence?

Answer 12

1. Anticholinergics
2. Cholinergics
3. TCA

Question 13

Mechanism and use of Anticholinergics?

Answer 13

Mechanism: Relax detrusor muscle + increase tone of urethra

Use:

• OAB (Overactive bladder)
• UUI (Urge urinary incontinence)
• Detrusor hyperactivity

Examples:

• Propantheline
• Oxybutinin
• Tolterodine
• Fexofenadine

Question 14

Mechanism and use of Cholinergics?

Answer 14

Almost always used in Overflow urinary incontinence (unable to contract detrusor muscle, full of urine). This will strengthen detrusor muscle. Useful in patients after surgery who has problems urinating.

Use:

• OUI (Overflow urinary incontinence)
• Detrusor hyperactivity

Examples:

• Bethanechol
• Neostigmine

Question 15

Mechanism and use of TCA

Answer 15

Has alpha-adrenergic activity, this allows relaxation of dome, and constriction of urethra.

Use:

• SUI (Stress urinary incontinence)
• UUI (Urge UI)
• Mixed urinary incontinence

Example:
Imipramine

Question 16

Typical features of Stress UI

Answer 16

= Urine leaks out with sudden pressure on the bladder, f.eks by activities like exercise, sneezing, laughing or coughing.

• No increased frequency
• No urinary urgency
• Small amount of urine loss
  Voluntary voiding
  Loss with valsalva
  S2-S4 reflex present
  Low IUP
• NO nocturnal sx
• Q-tip test: >30% motility

Question 17

Typical features of Urge UI

Answer 17

= A sudden, intense urge to urinate followed by an involuntary loss of urine. You may need to urinate often.

• Increased frequency
• Increased urgency
• Voluntary voiding
• No loss with valsalva
• Large amount lost
• Nocturnal sx!
• S2-S4 present
• Q-tip test < 30 (normal)
• Involuntary detrusor contraction

Question 18

Typical features of overflow UI

Answer 18

Bladder becomes too full(from f.eks blockage of uretra, weak bladder muscles unable to squeeze the bladder empty, injury of nerves from diseases such as diabetes, alcoholism, MS, Parkinsons, or medications.) and leaks.

• No increased frequency
• No increased urgency
• NO voluntary voiding
• Small, persistent loss
• Leakages during night
• ABSENT S2-S4-reflex
• Q-tip test < 30(normal)
• High residual volume

Question 19

Typical features of Bypass UI

Answer 19

bypassing of urine, may be a constant dribbling or dampness.

• No incr. frequency
• No urgency
• Voluntary voiding
• No loss w valsalva
• Small, persistent loss
• Nocturnal leak
• S2-S4 present
• Q-tp < 30 (normal)

Question 20

What is the “only” type of UI that does not have Sx at night?

Answer 20

Stress urinary incontinence

Question 21

What is the “only” type of UI that does elevate the Q-tip test?

Answer 21

Stress urinary incontinence

Question 22

Pathophysiology of Stress UI?

Answer 22

The pelvic floor supports the bladder and urethra. If this area gets stretched, weakened or damaged, then SUI can happen. Pregnancy and childbirth can cause this. Chronic coughing or nerve injuries to the lower back or pelvic surgery (like surgery for prostate cancer) can also weaken the muscles.

Patients are often postmenopausal (estrogen-loss decr. strength of pelvic floor), multiparous, past gyn.surgeries, obesity (higher intraabdominal pressure).

Question 23

Stress UI on physical examination:

Answer 23

Mostly unremarkable

• External : may be signs of atrophy
• Bulbocavernous and anocutaneous reflexes should be normal
• Loss of urine is often noted if pt is asked to strain.
• POSITIVE Q-tip test

Question 24

Diagnosis of Stress UI

Answer 24

1. Get an urinary analysis - should be normal
2. Urodynamic studies
   - Normally, during valsvalva, the IUP and abd. pressure increase together. In stress UI, the IUP does not rise with the abdominal pressure.
   - Post-voidal residual is normal.

Question 25

Etiologies of Stress UI

Answer 25

1. Weakening of pelvic floor (secondary to hypoestrogenism)
2. Direct injury to pelvic floor (childbirth,surgery)
3. Pregnancy - incr. abd.oressure
4. Obesity
5. Smoking
6. Certain medications
   - alpha-adrenergic antagonists (e.g phenoxybenzamine, trazodone)
   - Antipsychotics, antidepressants
   - ACE inhibitors if it causes significant cough

Question 26

Management of Stress UI

Answer 26

1. Behavioural modifications:
   - Scheduled bathroom visit, some women only have Sx when the bladder reaches a certain volume
2. Pelvic floor muscle strengthening (Kegel exercises)
3. Pessary(when in conjunction w/
4. Surgery
   - Urethral bulking agents
   - Retropubic urethropexy
   - Sling procedures (pubovaginal, midurethral) (se film om disse)

Question 27

Main pathological/Urodynamics of urge UI?

Answer 27

Involuntary detrusor contraction, even with small amounts of urine in the bladder

Question 28

Difference between Urge UI and Overactive bladder

Answer 28

In Urge UI - involuntary leakage accompanied by or immediately preceded by a strong imminent need to void, whereas in OAB it can be with OR without incontinence.

Question 29

Medical causes of urinary incontinence (“DIAPPERS”)

Answer 29

D - Dementia/Delirium or handicaps

I - Infection (UTI)

A - (Atrophic vaginitis)

P - Psychological

P - Pharmacological (EtOH, Caffeine, alpha blockers, ACEIs, CCBs, COX-2 - inhibitors, diuretics, narcotic analgesivs, TZDs)

E - Endocrine (DM, hypothyroidism)

R - Restricted mobility

S - Stool impaction

Question 30

Typical Sx of Urge UI

Answer 30

Increased urgency, which prompts them to need the bathroom enough to interfere w/daily activities. It is a large amount during an episode. Will not loose urine during coughing or sneezing, but mixed incontinence is normal . Nocturia and frequently waking to urinate is very common.

Question 31

Urge UI - Diagnosis

Answer 31

• May be atrophy
• Bulbocavernous and anocutaneous reflexes are normal
• Q-tip test negative
• Urodynamic studies are not indicated as part of the first line of diagnostics unless a neurological etiology is suspected. If performed, it would reveal involuntary detrusor contraction despite low urinary volume in bladder.

Question 32

Urge UI - Etiologies

Answer 32

• Most are idiopathic
• Neuromuscular etiologies: Spinal cord injury, stroke, MS, dementia, Parkinson’s disease, medullary lesions, diabetic neuropathy
• Iatrogenic: Urethral obstruction or compression secondary to bladder neck procedure
• Irritation: UTI, bladder stones, bladder cancer, foregin bodies, positive UA.
• Drugs: diuretics

Question 33

Management of Urge UI

Answer 33

Here, conservative Mx may not be enough, as it is the detrusor muscle that is the problem. However, you can try pelvic floor muscle strengtening. Caffeine should be avoided.

Pharmacologic tx:

1. Anticholinergic = gold standard.
   - Tolterodine
   - Fesoterodine
   - Oxybutinin
2. Beta-3 adrenergic agonists (relax the dome of the bladder)
   - Mirabegron
3. Tricyclic antidepressants
   - Imipramine
4. Topical estrogen (may be considered in pts w/concurrent atrophic vaginitis.

Question 34

Overflow UI - main pathology/urodynamics:

Answer 34

High residual volume, often because of nerve-paralysis by anaesthesia/surgery, or problems with the detrusor-muscle itself. Will dribble urine, because the bladder-pressure is so high. Cause can also be medications, detrusor insufficiency (bladder hypotonia) or detrusor areflexia (bladder acontractility).

Question 35

Typical Sx of overflow UI

Answer 35

Constant, slow loss of urine. Pt will describe an inability to voluntary void. If the pt is able to void, there will be difficulty in initiating and maintaining a stream.

Question 36

Overflow UI - physical exam

Answer 36

Px is mostly unremarkable, unless a neurological etiology is implicated:

• External genitalia is usually normal
• No vaginal diverticula should be noted
• Bulbocavernous reflex may be abnormal, indicating a neurologic etiology.

Question 37

Overflow UI - Diagnosis

Answer 37

1. Post- void residual is crucial for diagnosis (>50ml)
2. If urinary obstruction is suspected, CT is indicated to identify the site of obstruction
   (CT urography)
3. Urodynamic studies would reveal lack of involuntary detrusor contractions, despite a large volume of urine in bladder.

Question 38

Overflow UI - Management

Answer 38

1. Mx depends on underlying cause
   - Permanent lesion: long term intermittent self-catheterization. Placement of a suprapubic catheter is useful for many pts.

• Urinary obstruction: surgical correction to relieve the obstruction.

Question 39

Bypass UI - pathology

Answer 39

Caused by fistulas
The incontinence is somewhat similar to overflow incontinence, however, tha pt will be able to void when desired and there will not be an elevated PVR. Fistulas often become clinically apparent between 1-2 w postop.

Question 40

Bypass UI - Types of urinary tract fistulas

Answer 40

1. Vesicouterine fistula
2. Vesicovaginal fistula
3. Urethrovaginal fistula
4. Rectovaginal fistula

Question 41

Bypass UI - Etiologies

Answer 41

1. Most common in developing world = obstetric trauma, due to complicated labor/delivery (prolonged second stage, operative delivery)
2. In the US, the most common is pelvic surgery (especially hysterectomy) and pelvic radiation

Question 42

Bypass UI - Diagnosis

Answer 42

1. Labs + UA to rule out UTI etc.
2. Double dye test
   - Instillation of methylene blue into the bladder to identify a vesicovaginal fistula -> If positive the methylene blue will cross from the bladder into the vagina and stain the tampon/pad blue

• PO phenazopyridine (Pyridium) to identify a ureterovaginal fistula -> If positive, the Pyridium will cross from the ureters into the vagina and stain pad orange.

3. Direct visualization/imaging
   - CT uroscopy, IV pyelography, cystoscopy, retrograde pyelogram. -> Retrograde pyelography is the most definite test to diagnose a ureterovaginal fistula.

Question 43

Bypass UI - Management

Answer 43

Surgery