Urology Flashcards
3 common regions for renal stones to get deposited
1) Pelviureteric junction (coming out of renal pelvis)
2) Pelvic brim
3) Vesicoureteric junction (going into bladder)
Incidence and peak age, sex of renal stones
Lifetime incidence up to 15%
Peak age 20-40
M:F = 3:1
Types of stones
Calcium oxalate -75%
Magnesium ammonium phosphate (struvite/triple phosphate) - 15%
Also urate and more
6 x presentation features of renal stones
1) Renal Colic
2) UTI (increased risk if voiding impaired)
3) Haematuria
4) Proteinuria
5) Sterile pyuria
6) Anuria
Renal colic features
Excruciating ureteric spasms - loin to groin pain
Nausea and vomiting
Often cannot lie still
Renal obstruction - felt in loin
Mid-ureter - like appendicitis or diverticulitis
Lower ureter - bladder irritability and pain in scrotum, penile tip or labia
In bladder or urethra - pelvic pain and dysuria, Strangury (desire but inability to void)
Examination of kidney stones
No tenderness usually
May be renal angle tenderness, esp. on percussion if there is retroperitoneal inflammation
Urine dip in kidney stones
Usually +ve for blood
Imaging of stones
Spiral non-contrast CT is the best (helps exclude ruptured AAA which presents similarly)
Initial management of stones
Analgesia - diclofenac or opioids
IV fluids - help pass stone
Antibiotics eg. cefuroxime or gentamicin
Management of stones
Most past spontaneously - increase fluid
Management of stones >5mm/pain not resolving
Medical expulsive therapy - nifedipine or alpha-blocker (tamsulosin)
This promotes expulsion and reduces analgesia requirements
If still not passing
Extracorpeal shockwave lithotripsy - shatters stone - SE: renal injury and may cause DM
Ureteroscopy using basket (if pregnant)
Percutaneous nephrolithotomy - keyhole surgery to remove stones when large, multiple or complex (intracorporeal lithotripsy or stone fragmentation)
Prevention of stones
Drink plenty
Normal Ca2+ dietary intake- low stimualtes oxalate excretion
Low salt diet
Prevention of calcium stones
Thiazide diuretic used to decrease calcium excretion
What increases oxalate levels? (therefore avoid if oxalate stones)
Chocolate Tea Rhubarb Strawberries Nuts Spinach
Causes of urinary tract obstruction
1) Luminal - stones, sloughed papilla, blood clots, tumour (renal, ureteric or bladder)
2) Mural - stricture, neuromuscular dysfunction
3) Extra mural - Abdominal/pelvic mass or tumour, retroperitoneal fibrosis
Features of acute upper tract obstruction
Loin pain radiating to groin
May be superimposed infection which can cause loin tenderness
Or enlarged kidney
Features of chronic upper tract obstruction
Flank pain
Renal failure
Superimposed infection
Polyuria due to impaired urinary concentration
Features of acute lower tract obstruction
Acute urinary retention
Suprapubic pain
Distended palpable bladder - dull to percuss
Features of chronic lower tract obstruction
Urinary frequency, hesitancy Poor stream, terminal dribbling Overflow incontinence Distended palpable bladder PR may feel large prostate
Imaging of UT obstruction
USS
Treatment of UUT obstruction
Nephrostomy or ureteric stent
A-blockers (tamsulosin) to reduce stent-related pain from spasm
Pyeloplasty - widen PUJ - if idiopathic PUJ obstruction
Treatment of LUT obstruction
Catheter insertion - urethral or suprapubic
Treat underlying cause
NB: Large diuresis after relief of obstruction - can cause temporary salt-losing nephropathy
What is urinary retention?
Not emptying the bladder
Due to obstruction or decreased detrusor power
What happens in acute urinary retention?
Bladder usually tender and containing about 600ml of urine
Causes of acute UR
Prostatic obstruction - usual cause in men Urethral strictures Anticholinergics Psychological 'holding' Alcohol Constipation Post op - pain/inflammation or anaesthetics Infection Neurological - cauda equina syndrome Carcinoma
Examination in acute UR
Prostate - DRE
Abdominal exam
Perineal sensation - Cauda test
Tricks to aid voiding
Analgesia Privacy on wards Ambulation Standing Running taps or in a hot bath
If tricks fail
Catheterise
Start alpha-blocker - tamsulosin
after 2-3 days trial without catheter - continue tamsulosin
Prevention of acute UR
Finasteride - decreased prostate size
Tamsulosin
Presentation of chronic UR
More insidious and may be painless
Bladder capacity can be >1.5L
Overflow incontinence, acute on chronic retention, lower abdominal mass
UTI
Renal failure
Causes of chronic UR
Prostatic enlargement - common
Pelvic malignancy
DM
CNS disease
Management of chronic UR
Only catheterise if pain, urinary infection or renal impairment
Otherwise treat underlying cause
Prevalence of benign prostatic hyperplasia
Common - 24% aged 40-64
40% 65+
What happens in BPH
Benign nodular or diffuse proliferation of musculofibrous and glandular layers of the prostate
Inner zone enlarges (unlike outer zone enlargement in prostate carcinoma)
Features of BPH
LUTS - nocturia, frequency, urgency, post-micturition dribbling, poor stream, overflow incontinence, haematuria and bladder stones - UTI
Tests in BPH
Rule out cancer - PSA and transrectal USS + biopsy
Lifestyle changes in BPH
Avoid caffeine and alcohol
Relax when voiding, void twice in a row, practise “holding on”
Medication what and when?
Mild disease and when waiting for surgery
A-blockers - tamsulosin (doxazosin, terazosin) SE: ED, drowsiness, depression, dry mouth, hypotension, weight gain)
5alpha-reducatase inhibitors -eg. finasteride - prevent testosterone conversion to dihydrotestosterone - reduce prostate size - excreted in semen SE: impotence and decreased libido
Surgery in BPH
Transurethral resection of prostate - 14% become inpotent - beware of bleeding and TURP syndrome (absorption of washout causing hyponatraemia and fits)
Transurethral incision of prostate - same benefit as TURP but less risk to sexual function and less destruction
- best option for small glands
Retropubic prostatectomy - open operation if prostate very large
Transurethral laser-induced prostatectomy - may be as good as TURP
Warnings to patients having TURP
Haematuria - first 2 weeks, haematospermia, hypothermia, urethral stricture, post TURP syndrome, infection, ED, incontinence, retrograde ejaculation
Avoid driving and sex for 2 weeks
Main cause of incontinence in men
Enlargement of prostate
Urge incontinence
2 types of incontinence in women
Stress incontinence - when raised intraabdominal pressure - eg. coughing, laughing - common in pregnancy and following birth
Urge incontinence/overactive bladder syndrome - urge to urinate quickly followed by emptying of bladder
Things which precipitate urgency/leaking in urge incontinence
Coming Home Cold Sound of running water Coffee, tea, coke Obesity
Cause of urge incontinence
Detrusor overactivity (central inhibition decreased or peripheral sensitisation) or a bladder muscle problem
Management of stress incontinence
Pelvic floor muscle exercises - 8 contractions 3x day for 3 months
Intravaginal electrical stimulation
Surgical management of stress incontinence
Tension-free vaginal tape - to stabilise mid-urethra
Urethral bulking
Medical management of stress incontinence if surgical not an option
Duloxetine (SNRI)
Management of urge incontinence
Look for spinal cord problems and for vaginitis
Bladder training and weight loss = important
Male = consider condom catheter
Medical management of urge incontinence
Antimuscarinics eg. tolterodine (solifenacin or oxybutynin)
Topical oestrogen - raise bladders sensory threshold
B3 adrenergic agonist - mirabegron - if antimuscarinics CI or unsuccessful
Management of urge incontinence if original medical treatment unsuccessful
BOTOX
Percutaneous posterior tibial nerve stimulation - if BOTOX not wanted
What type of stones does Proteus cause
Magnesium ammonium phosphate (struvite) stones
- often form large calculi (staghorn)
What type of stones are associated with hyperparathyroidism
Calcium phosphate renal stones
