32 - Micturition Flashcards
Where is the micturation centre and what is it’s function
Back of the neck (pons)
Ask if socially acceptable
What is the sensory feedback in micturition, What nerve?
Bladder to MC via stretch receptors
S2,3,4 branch of pelvic nerve
Somatic to sphincter pathway and nerve?
Micturition centre to external sphincter Via somatic nerves Pudendal nerve = S2,3,4 Relaxes external sphincter to open Sympathetic inhibited (hypogastric nerve)
Parasympathetic to detrusor
Feedback loop and parasympathetic supply to detrusor muscle
Contracts
Pelvic nerves S2,3,4
How much does a normal adult micturate
4 times/24 hours
1.5L
What stimulates bladder contraction
Ach released from nerve endings and that stimulates muscarinic receptors on the detrusor smooth muscle
What drug for overactive bladder
Anti-muscarinic drugs
Side effects of anti-muscarinic drugs
Dry mouth
Storage symptoms of LUTI
Frequency, nocturia, urgency, urge incontinence
Voiding symptoms of LUTI
Hesitancy, poor flow, incomplete emptying, terminal dribbling, haematuria
Overactive bladder syndrome
Urgency, with or without incontinence, usually with increased frequency and nocturia
Diagnosing BPH
International prostate symptom score (I-PSS)
What is the IPSS
Questions about symptoms
Mild I-PSS
(I-PSS)
Reassure, watch and wait, reassess
Moderate I-PSS
(8-19)
Severe IPSS
20-35
Low vs high QoL score
Low - watch and wait
High - Lifestyle and education, medication, surgery
Investigations for urinary issues
Urine sample, uroflowmetry and post void residual volume
Urodynamics (pressure/flow studies) - flow decreases with age
Obstruction disorders
BPH, Lithiasis, strictures, cancer
Incontinence disorders
Stress, urge, mixed urinary incontinence
Functional disorders
Stroke, spinal cord injury, neurological disease
Medical disorders
Cardiac, hepatic and renal failure
What is BPH
Prostate gland enlarges
Thickened bladder that can fail
End-fill over activity (generating large amounts of pressure and small flow)
Conservative treatments for BPH
Fluid type, amount, food, smoking
Don’t drink to little (can irritate bladder)
Voiding diary
Caffeine effect on bladder
Caffeine releases calcium stores from the golgi apparatus in the bladder wall, making bladder contraction more likely
What is a bladder drill
Store for 3-4 hours then pee
Medical therapy for BPH
- A blockers: Stretchers for smaller prostates
- 5-a reductase inhibitors : shrinkers (bigger prostates)
- PDE5 inhibitors
What surgery options for BPH
TURP
HoLEP/greenlight
UroLift
What is TURP
The gold standard, electric loop carves out prostate chips
- ED issues
HoLEP/greenlight
Modern laser operation, better at tissue removal
- No ED
UroLift
Staples prostate
What is stress urinary incontinence and how do you treat
Increased abdomen pressure
leaking on effort or exertion
- Surgery
Urge UI
Leakage and urgency
- Treat with medication
Anticholinergics
Oxybutynin
Solifenacin
Tolterodine
Fesoterodine
MoA of anticholinergics
Block ACH in parasympathetic nerves
blocks elsewhere too like salivary gland
B3 Adrenergics MoA + SE
Activates receptors on the detrusor to relax
- Upregulated int OAB
- Hypertension
B3 adrenergic drug
Mirabegron
Botulinum Toxin A MoA
Fuses synaptic vesicles with the motor end plate
- Used for over active bladder
lesion above the pontine micturation centre?
Safe
CVA, Parkinsons MS
Lesion below T-12
Safe
as bladder and sphincter are flaccid + low pressure
(trauma, tumours,spina bifida)
Lesions between pontine mucturation centre => T12
Unsafe
uncoordinated + so high pressures in the resting bladder result
(RTA, Tumours, MS)
