Urinary tract obstruction Flashcards
what comprises the upper urinary tract (i.e. supra-vesical)
- PUJ - pelvo-ureteric junction
- ureter
- VUJ - vesico-ureteric junction
what comprises the lower urinary tract (i.e. bladder outflow obstruction)
- bladder neck
- prostate
- urethra
- urethral meatus
- foreskin (eg phimosis)
what are the two types of causes of UPPER tract obstructions
intrinsic and extrinsic
what are the PUJ INTRINSIC obstructions
- PUJ obstruction (physiological)
- Stone
- Ureteric tumour (TCC)
- Blood clot from e.g. renal tumours
- Fungal ball- more common in the elderly
what are the PUJ EXTRINSIC obstructions
- PUJ obstruction (crossing vessel)
- Lymph nodes (tumour
- Abdominal mass (tumour)
what are the ureter INTRINSIC obstructions
- Stone
- Ureteric tumour (TCC)
- Scar tissue
- Blood clot
- Fungal ball
what are the ureter EXTRINSIC obstructions
- Lymph nodes (tumour, retroperitoneal fibrosis)
- Iatrogenic - usually from surgery
- Abdominal/pelvic mass (tumour, pregnant uterus)
what are the VUJ INTRINSIC obstructions
- stone
- bladder tumour
- ureteric tumour
what are the VUJ EXTRINSIC obstructions
- cervical cancer
2. prostate cancer
where are abdominal masses most likely to cause obstructions
in mid-lower thirds of the ureters
what are the symptoms for Upper tract obstructions
- can be asymptomatic - picked up in e.g. ante natal scanning
- pain - usually with acute obstruction
- frank haematuria
- symptoms of complications - e.g. symptoms of renal failure, primary tumour, etc
what are the signs of Upper tract obstruction
- palpable mass - more common in neonates and the elderly
- microscopic haematuria
- signs of complications - e.g. signs of renal failure, primary tumour, etc
what are complications of Upper tract obstruction
infection and sepsis, renal failure
CASE: 50yr old man - left sided colicky loin pain, nausea, vomiting, no PMH, no medications
On examination - 40C temp, 100BPM pulse, BP 90/60, RR 20 bpm, O2 sat 89% on air
what should the first step in his management be and what investigations should be organised
- fluids - to sort BP
- antibiotics - for infection
- analgesia - for pain
order urine sample
order CT
- must be NON-CONTRASTED
- don’t know his renal function yet
CASE: CT showed
- stone in right upper ureter
- perinephric stranding on right kidney (kidney looks hazy with puddle in the centre (urine)
what does this indicate the man has
PYELONEPHROSIS
- infection of the kidneys WITH obstruction
**pyelonephritis - infection of the kidneys WITHOUT obstruction
what are the resuscitation treatments of Upper tract obstruction
- ABCs
- IV access, ABG, urine, and blood cultures, fluid balance monitoring
- IV fluids, borad-spectrum antibiotics (if appropriate)
- Analgesia
- HDU care +/-renal replacement therapy (if appropriate)
what are the emergency treatments of Upper tract obstruction
- percutaneous nephrostomy insertion
2. retrograde stent insertion
what are the definitive treatments of Upper tract obstruction
TREAT UNDERLYING CAUSE
- e.g. stone - uteroscopy and laser lithotripsy
- e.g. ureteric tumour - radial nephropureterectomy
- e.g. PUJ obstruction - laparoscopic pyeloplasty
CASE: considering all the available treatments - what one would be best suited for our patient and why
percutaneous nephrostomy insertion - i.e. it is something to de-obstruct the kidney as fast as possible
percutaneous puncture - usually done under LA and sedation - US or Xray guidance
CASE: why would the other emergency treatment not be suitable
Ureteric stent - due to its position it may not get past stone into kidney - may accuse hole in delicate ureter
CASE: why must you never give shock therapy to break up stones if a patient is infected
if the stone is infected and breaks up - can cause sepsis as bacteria spreads through blood
- only use shock to break it up once infection has settled
how does a Lower tract obstruction present
- LUTS - including incontinence
- acute urinary retention
- chronic urinary retention
- recurrent urianry tract infection and sepsis
- frank haematuria
- formation of bladder stones
- renal failure
If a patient presents with retention what is the immediate treatment needed
catheterisation (foley catheter - ballon end)
- urethral catheter 14/16F*
- record residual
- 2 attempts (then introducer if GA experience)
- 16F SPC if urethra impassable
*16F = 16 French = 16mm diameter
CASE: two people arrive in hospital
- 65yrs acute retention
- can’t pass urine
- in agony
- creatinine 70 - 65yrs chronic retention
- can pass urine fine
- been wearing bigger trousers due to bloating
- pain free
- creatinine 170
WHO GETS THE BED??
Chronic retention gets the bed due to high creatinine - may need more monitoring
acute can be catheterised and sent home as creatinine levels normal
what are the resuscitation treatments for Lower tract obstruction
- ABCs
- IV access, bloods, ABG, urine and blood cultures, fluid balance monitoring
- IV fluids, broad-spectrum antibiotics (if appropriate)
- Analgesia
- HDU care +/- renal replacement therapy (if appropriate)
what are the emergency treatments for Lower tract obstructions (for unremitting pain or complications)
- Urethral catheterisation 2. Suprapubic catheterisation
what are the definitive treatments for Lower tract obstructions
TREAT UNDERLYING CAUSE
- e.g. BPE – TURP
- e.g. Urethral stricture – Optical urethrotomy
- e.g. Meatal stenosis – Meatal dilatation
- e.g. Phimosis – Circumcision
what are the two types of chronic retention
high pressure and low pressure
what are the indicators for high pressure chronic retention
painless
incontinent
raised cr
bilateral hydronephrosis
what are the indicators for low pressure chronic retention
painless
dry
normal cr
normal kidneys
what are complications of Lower tract obstruction
- decompression haematuria
2. post obstructive diuresis
what happens in decompression haematuria
shearing of small vessels as decompression occurs due to differing compliance of tissue layers - usually self limiting
what is post obstructive diuresis
diuresis brought on when disrupting an obstruction in the upper or lower tract
- the passing of more than 150-200ml/hr urine
- osmotic diuresis secondary to urea, ADH, altered tubular function
- can lead to life threatening Na and water depletion
how is post obstructive diuresis managed
saline
input = output-30ml/hr
