Obstructive Uropathy

Question 1

Outline the pathogenesis of obstructive uropathy

Answer 1

• Interruption of the urinary flow
  
  • Renal stones, BPH, prostate cancer, bladder tumours
• Back-pressure on kidney
  
  • Decreased GFR, RAAS increase
• ATN and interstitial renal fibrosis
  
  • Loss of urinary concentration ability

Question 2

What are some risk factors for obstructive uropathy?

Answer 2

• BPH
• Constipation (associated finding, generally)
• Diuresis (EtOH, diuretics)
• Drugs (anticholinergics, narcotics, a-agonists)
• Urolithiasis
• Neuropathy affecting bladder
• Malignancy
• Clot retention

Question 3

What might be some history/examination findings in a patient with obstructive uropathy?

Answer 3

• Distended abdomen
• Inability to urinate
• LUT symptoms
• Palpable bladder
• Cause-related/complications
  
  • Fever, flank pain

Question 4

What tests could be considered to confirm a diagnosis of obstructive uropathy?

Answer 4

• Renal ultrasound
• CT pyelogram
• FBE/UEC (infection?)

Question 5

Outline the prinicples of management of obstructive uropathy

Answer 5

• Establish drainage (catheter)
• Calculi
  
  • Analgesia and rehydration
  • Alpha-blockers/surgical removal and/or stenting, nephrostomy
• Non-calculi
  
  • Analgesia and antibiotics
  • Stent/nephrostomy/TURP as required (treatment of underlying cause)
• Trial of void