Urinary retention: includes male LUTS lecture Flashcards
1
Q
LO: Explain the mechanisms by which urinary retention occurs:
obstruction of the urethra, weakened bladder muscle, and innervation problem
Define urinary retention
What are the two types of urinary retention?
A
- Define urinary retention: bladder that does not empty completely, or at all
-
Acute urinary retention:
- sudden inability to pass urine
- usually painful/ uncomfortable, tender distended bladder
- residual urine ~600 ml
- requires emergency catheterisation
- It can cause: UTI, AKI, post obstructive diuresis, hydronephrosis
-
Chronic urinary retention:
- Gradual (months- years) development of urinary retention
- often asymptomatic and painless with postvoidal residual urine
- High pressure- affects renal function
- BPH is the most common cause
- Can cause: UTI, AKI, post obstructive diuresis, hydronephrosis
- Can get acute on chronic –> painful with large residual urine
2
Q
What are the causes of acute urinary retention?
A
-
Obstruction of the urethra:
- BPH
- urethral stricture - narrowing or closure of urethra, post UTI, surgery/ injury, prostatitis, meatal stricture (opening at end of urethra becomes constricted)
- urinary tract stones or clot retention following haematuria
- cystocele - bulging of bladder into the vagina, abnormal position causes compression of urethra
- rectocele - bulging of rectum into vagina, may compress urethra
- constipation - hard stools in rectum compress urethra
- tumour - renal cancer, ureter, bladder, prostate, urethral, retroperitoneal masses
- gravid uterus
- fibroid or ovarian cyst - obstruct urethra
-
Nerve problem -
- cauda equina
- cord compression
- trauma
- parkinson’s
- MS
- diabetes
-
Medication
- anticholinergics
- opiods
- BZDs
- NSAIDs
- alcohol
- CCB’s
- antihistamines
- TCA’s
- Weakened bladder muscle
3
Q
Explain the physiology underlying the micturition process:
Explain underlying neurology of storage phase
A
- micturition has two discrete phases: storage/continence phase and voiding phase
- Continence phase:
- controlled by continence centres in the brain –> control continence centres of spinal cord
- storage requires detrusor relaxation and simultaneous contraction of both internal and external urethral sphincters
- bladder and IUS under control of SNS
- EUS under control of somatic NS
- SNS –> From cerebral cortex to pons (pontine continence centre) –> sympathetic nuclei spinal cord –> Sympathetic hypogastric nerve (T10-L2) –> detrusor muscle relaxation (B3 adrenoreceptors) and contraction IUS (stimulates alpha 1 adrenoreceptors) at bladder neck.
- EUS under voluntary somatic control –> impulses to EUS travel via Pudendal nerve (S2-S4) to nAchR on muscle of EUS.
4
Q
Explain underlying physiology of voiding process:
A
- Destrusor muscle relaxes as the bladder fills, rugae distend and constant pressure in bladder is maintained = stress- relaxation phenomenon
- capacity of bladder 300-550 ml, afferent nerves in bladder wall signal need to void at ~400ml
- passing of urine under parasympathetic control - bladder afferents signal ascend through spinal cord and project to pontine micturition centre and cerebrum
- upon voluntary decision to urinate neurones from pontine micturition centre fire to excite sacral preganglionic neurones
- subsequent parasympathetic stimulation of pelvic nerve (S2-S4) causes release of Ach –> M3 muscarinic Ach receptors on destrusor muscle –> contraction
- Pontine micturtion centre inhibits SNS stimulation of internal urethral sphincter –> relaxation
- conscious reduction in voluntary contraction of external urethral sphincter from cerebral cortex allows distention of urethra and urine passing.
5
Q
LO: Understand common and important causes of urinary retention including:
BPH pathophysiology
A
- BPH pathophysiology: increased proliferation of stromal and epithelial cells of prostate gland with decreased apoptosis, arises in periurethral and transition zones of the prostate. Results in bladder outlet obstruction - both due to increased epithelial tissue and increases in stromal smooth muscle tone. Large number of alpha adrenergic receptors in prostate caspule/stroma/bladder neck.
6
Q
LO: understand the common and important causes of urinary retention including:
BPH History/ Key Features
A
Presentation: Storage symptoms and Voiding symptoms
- Frequency
- urgency
- nocturia
- incontinence
- weak stream
- dribbling
- dysuria
- straining
- incomplete emptying
7
Q
LO: understand the common and important causes of urinary retention including:
BPH Key examination features
A
- DRE:
- prostate volume > 30 g
- nodules or tenderness–> suspicious of prostate cancer or prostatitis.
- Assess anal sphincter tone
- assess prostate for nodule or rectal masses
- Smooth, soft prostate with pain = prostatitis
- Smooth rubbery = BPH
- Lumps/ hard/ irregular areas = prostate cancer.
- Abdo exam for palpable bladder –> inspection of external meatus
- neurological assessment
8
Q
LO: describe what bedside/clinical/lab/radiological investigations appropraite to investigate urinary retention
BPH: investigations
A
-
Urinary frequency/ volume chart for a few days
- polyuria > 3 L urine in 24 hours
- Bedside urinalysis to rule out UTI
-
Lab: Serum PSA - dependent on findings of DRE
- Offer PSA testing in men > 50 yrs who request/ symptomatic men
- consider if LUTS present, ED, visible haematuria, unexplained symptoms that could be due to advanced Prostate CA - lower back pain, WL, bone pain
- PSA produced by normal and cancerous prostate cells.
- secreted into prostate fluid and semen, small amounts present in blood
- due to altered architercture higher leakage into blood w prostate CA
- Blood PSA inaccurate marker - CA can be present w/out increased PSA, PSA can be increased due to BPH/ prostatitis/ UTI
- International prostate symptom score (IPSS) - reliable accurate predictor of LUTS, self reported questionnaire QOL
- USS scan –> of renal tract and used to calculate the volume of the prostate, alongside investigation for urinary retention and hydronephrosis. Prostate > 30 ml considered enlarged.
-
Urodynamic studies:
- Uroflowmetry (pee into funnel calculates volume/ rate of flow/ length of time).
- post voidal residual bladder volume USS/ catheter removal of remaining urine volume
- Cystometric test - bladder emptied, then filled with warm water via catheter which also measure the pressure within the bladder, individual asked when need to urinate arises, may measure leak point measurement. Pressure flow study also possible, indivudal asked to urinate, pressure within bladder and flow rate calculated.
- Pressure flow rate identifies bladder outlet blockage vs detrusor inactivity.
- Imaging –> if chronic retention/ recurrent UTI/Haematuria, renal insufficiency or urolithiasis.
9
Q
Describe the initial approach of management for the patient with urinary retention:
BPH management
A
- Minimal symptoms –> watchful waiting + reassurance, can have medication review, + moderate caffiene and alcohol
- moderate- severe symptoms –> Medication:
-
Alpha adrenoreceptor antagonist/ Alpha blockers –> Alpha 1a Receptors on prostate, bladder neck, urethra
- Tamsulosin –> smooth muscle relaxant acting on bladder neck, can cause hypotension
- Doxazosin - non selective alpha 1 receptor blocker - vasodilator
-
If they remain symptomatic –> 5 alpha reductase inhibitor - Finasteride
- inhibits synthesis of dihydrotestosterone which stimulates prostatic growth (can take up to 6 months to feel symptomatic benefit).
- Surgery –> If recurrent retention unresponsive to medication, recurrent haematuria, renal insufficiency, bladder stones.
-
Alpha adrenoreceptor antagonist/ Alpha blockers –> Alpha 1a Receptors on prostate, bladder neck, urethra
10
Q
What are the surgical approaches to resect the prostate?
What are the complications of this procedure?
A
TURP - transurethral resection of the prostate:
Involves accessing the prostate through the urethra and shaving the excess prostate tissue using diathermy, aiming to create a wider space for urinary flow.
Other options:
Transurethral electrovaporisation of the prostate (TUVP)
Holmium laser enucleation of the prostate (HoLEP)
Open prostatectomy via abdominal or perineal incision
Complications:
- FIRES - failure to resolve symptoms, incontinence, retrograde ejaculation, erectile dysfunction, strictures. (+ bleeding and infection).
11
Q
Understand the common causes of urinary retention:
Urethral stricture Pathophysiology
A
- Urethral stricture = narrowing of the urethra, normally from scar tissue
- result of inflammatory, ischemic, or traumatic processes –> lead to scar tissue formation which contracts and reduces caliber of the urethral lumen, increased resistance to antegrade flow of urien
- Uncommon in men + rare in women.
12
Q
LO: Describe key questions from the history that differentiate causes:
Urethral stricture
A
- Few symptoms at the start
- decrease in force of stream
- spraying or double stream
- terminal dribbling
- frequency
- urinary intermittency
- urine infection
- decrease force ejaculation
- dysuria
13
Q
LO: Describe key findings from the examination which could help differentiate between causes
Urethral stricture examinations?
A
- General abdo
- palpate bladder
- DRE
- prostate
14
Q
Investigations for urethral stricture?
A
- max voiding flow rate
- cystoscope
- endoscopic evaluation
- radiography –> retrograde urethrogram (RUG) or antegrade cystourethrograms if suprapubic catheter –> document location and extent or stricture.
- ultrasonography –> evaluate stricture length, degree, depth
15
Q
Management of urethral strictures?
A
- treat UTI prior to surgical intervention
- surgical treatment –> indicated when patient has severe voiding sx/ bladder calculi/ increased postvoid residual/ UTI/ conservative management fails
- urethral dilation (often requires repeats)
- internal urethrotomy –> incising stricture transurethrally to release scar tissue
- permanent urethral stent –> urethroplasty
- Open reconstruction –> complete excision of fibrotic urethral segment with reanastamosis
20
Q
LO: describe key questions from history and findings from exam to differentiate causes:
Gynaecological problems:
Cystocele
LO: What investigations would you do?
A
In history: sensation of vaginal pressure, incontinent, constipation, sexual dysfunction
In exam: vaginal protrusion
Investigations: Bladder USS
29
Q
Prostate anatomy:
Outline
What region is felt during DRE
what is the vasculature (link to metastasis) and innervation?
A
- Prostate = size of walnut, 2/3rds glandular, 1/3 fibromuscular, surrounded by thin fibrous capsule (adventitia)
- Histologically divided into three zones:
- Central zone - surrounds ejaculatory ducts (25% volume) –> ducts of the glands empty into prostatic urethra
- transitional zone - located centrally, surrounds urethra (5-10% volume) - glands of transitional zone typically under BPH
-
peripheral zone - main body of the gland (65%) and located posteriorly.
- Peripheral zone is mainly the area felt against the rectum on DRE
- ducts of glands of peripheral zone empty vertically –> may permit urine reflux, higher incidence of inflammation in these compartments and linked to high incidence of prostate carcinoma
- 4th zone - fibromuscular stroma - situated anteriorly in the gland smooth and striated muscle forms around internal and external urethral sphincter.
Vasculature:
- Prostatic arteries derived from internal iliac arteries (receives some branches from internal pudendal and middle rectal arteries)
- venous drainage –> prostatic venous plexus –> drains to internal iliac veins –> via batson’s plexus (valveless plexus connect deep pelvic veins to internal vertebral venous plexus).
Innervation –> inferior hypogastric plexus
30
Q
management of prostatic cancer?
A
- If the prostate specific antigen level in men > 50 yrs is > 3 ng/mL or higher –> refer urgently for 2WW pathway to urological cancer
- If within normal range there is a low risk of prostate cancer, refer only if abnormal DRE or symptomatic.
- If low risk –> watchful waiting which includes regular GP appt and PSA testing.
- If patients with confirmed prostate cancer but low prognostic risk can do active surveillance –> repeated PSA/DRE and biopsies at regular intervals, if disease progresses they are eligible for radical treatment.
- If higher risk prostate cancer (e.g. locally advanced, relapse after radiocal radiotherapy) radical prostatectomy which involves a number of options.
- External beam radiotherapy (EBRT) directed at prostate
- Brachytherapy –> radioactive seeds implanted into the prostate, delivers continuous targeted radiotherapy to the prostate.
- Hormonal therapy –> antiandrogen therapy: prostate grows in response to androgens like testosterone, block hormones and therefore stop or slow prostate cancer growth. SE’s of hot flushes, sexual dysfunction, gynaecomastia, fatigue and osteoporosis.
- Bilateral orchidectomy = gold standard, surgical castration, removal of both testicles, option for locally advanced and metastatic prostate cancer, stops production of androgens.
- Advanced -> adjunctive and palliative –> androgen withdrawal - bilateral orchidectomy or LHRH agonists e.g. goserelin- synthetic LHRH, leads to sustained reduction in testosterone) or, androgen blockade (e.g. bicalutamide) chemotherapy.
- prevention: 5 alpha reductase inhibitor.
