Urinary retention

Acute retention

  • The bladder is usually tender containing around 600ml of urine
  • In men it is usually caused by BPH precipitated by;
    • Anticholinergics
    • Holding on
    • Constipation
    • Pain
    • Anaesthetics
    • Alcohol
    • Infection
  • Examine
    • Abdomen
    • PR
    • Perianal sensation
  • Tests
    • MSU, FBC, U&Es, PSA
    • US
  • Prevention
    • Finasteride - reduces prostate size
    • Tamulosin - reduces risk of need recatheterised after acute rejection

Chronic retention

  • Bladder capacity may be 1.5l
  • May present with;
    • Overflow incontinence
    • Acute on chronic retention
    • Lower abdominal mass
    • UTI
    • Renal failure
  • Causes;
    • Prostatic enlargement
    • Pelvic malignancy
    • Rectal surgery
    • DM
    • CNS disease e.g. transverse myelitis/MS
  • Only catheterise if there is pain, urinary infection or renal impairment

Benign prostatic hypertrophy

  • Common
  • Associated with;
    • Frequency
    • Urgency
    • Voiding difficulties
  • Management
    • PR exam
    • MSU, U&Es
    • Ultrasound
    • Rule out cancer - PSA, transrectal ultrasound and biopsy
  • Treatment
    • Watch and wait
    • Transurethral resection of the prostate
      • Consider peri-operative antibiotics e.g cefuroxime
      • Risk of impotence
      • Beware excessive bleeding post-op and clot retension
    • Transurethral incision of the prostate
      • Involves less destruction than the TURP and less risk to sexual function
      • Best surgical option for those with small glands
    • Retropubic prostatectomy
      • Open operation
    • Transurethral laser induced prostatectomy
    • Drugs;
      • ?-blockers eg. Tamsulosin, these reduce smooth muscle tone SE - drowsiness, depression, dizziness, reduced BP, dry mouth, ejaculatory failure, extra-pyramidal signs
      • 5?-reducatase inhibitors e.g finasteride, these reduce testosterones conversion to dihydroxytestosterone. It is excreted in semen so warn them to use condoms and that women shouldn’t handle crushed pills. SE - impotence and reduced libido

 

Management of obstructive uropathy

  • Insert catheter
  • Get urgent US of renal tract
  • Treat hyperkalaemia
  • Metabolic acidosis - on ABG there is likely to be a respiratory compensated metabolic acidosis
  • Post-obstructive diuresis - after relief of obstruction, kidneys can produce a lot of urine - provide resuscitation fluids to match input to output
  • Sodium-bicarbonate losing nephropathy - replace with isotonic 1.26% sodium bicarbonate solution
  • Infection - treat, keeping in mind that raised WCC and CRP may be due to the stress response

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Disclaimer: These notes are my own personal study aid - DO NOT use them for medical advice!