Obstruction Flashcards
Causes of urinary tract obstruction
1. Luminal Stones Blood clots Sloughed papilla 2. Mural Congenital / acquired stricture Tumour: renal, ureteric, bladder Neuromuscular dysfunction 3. Extramural Prostatic enlargement Abdo / pelvic mass / tumour Retroperitoneal fibrosis
Acute presentation of obstruction
- Upper urinary tract:
Flank plain
Renal failure - Lower urinary tract:
Frequency, hesitancy, poor stream, terminal dribbling, overflow incontinence
Distended, palpable bladder ± large prostate on PR
Investigations of obstruction
Bloods: FBC, U+E
Urine: dip, MC+S
Imaging:
Ultrasound: hydronephrosis or hydroureter
Anterograde / retrograde ureterograms
Radionucleotide imaging: renal function
CT/MRI
Treatment of obstruction
Upper tract: Nephrostomy or ureteric stent
Lower tract: Catheter
Ureteric stent complications
Infection Haematuria Trigonal irritation Encrustation Obstruction Ureteric rupture Stent migration
Urethral stricture causes
Trauma
Infection: e.g. gonorrhoea
Chemotherapy
Balantitis xerotica obliterans
Presentation of urethral stricture
Hesitancy Strangury Poor stream Terminal dribbling Pis en deux
Examination for urethral stricture
PR
Palpate urethra through penis
Examine meatus
Investigations for urethral stricture
1.Urodynamics ↓ peak flow rate ↑ micturition time 2. Urethroscopy and cystoscopy 3. Retrograde urethrogram
Treatment of urethral stricture
Internal urethrotomy
Dilatation
Stent
Obstructive uropathy pathogenesis
Acute retention on a chronic background may go unnoticed for days due to lack of pain.
Serum creatinine may be up to 1500uM
Renal function should return to normal over days
Some background impairment may remain.
Complications of obstructive uropathy
Hyperkalaemia Metabolic acidosis Post obstructive diuresis - require fluids Na/HCO3 losing nephropathy Infection
