23 Urinary Tract Obstruction Flashcards
What are some non malignant causes of changes to urinary flow? (5)
- BPH
- UTI
- Urinary tract stone disease
- Urological emergencies (urinary retention, acute loin pain, acute renal failure, systemic sepsis, spinal cord compression)
- Urological trauma
Causes for urinary obstruction can be classified as either intraluminal, intramural or extraluminal. Give an example of a cause for each category.
- Intraluminal: stones, sloughed papilla (papillary necrosis), clots
- Intramural: PUJO, benign strictures from TB or surgery
- Extraluminal: retroperitoneal malignancy, retroperitoneal fibrosis, bladder cancer, prostate cancer
How does acute ureteric obstruction present, what is it usually caused by and how do we diagnose it?
Presentation:
- Acute severe flank pain radiating to groin
Causes:
- Renal colic due to calculus (stone)
- Can be pyonephrosis on top
Diagnosis:
- Need plain CT or ultrasound
- Emergency as can develop sepsis*
How does chronic ureteric obstruction present, what is it usually caused by and how do we diagnose it?
Presentation:
- Painless
Cause:
- Often due to external obstruction
(Bi or uni lateral)
Diagnosis:
- Often found incidentally or during renal failure
What is the definition of obstructive uropathy? How can it cause hyperkalaemia?
Renal impairment due to bilateral or uni lateral ureteric obstruction, or high pressure chronic retention
Hyperkalaemia: -high pressure chronic retention –> reflux back into kidneys
What is pyonephrosis?
Infection of the kidneys’ collecting system due to obstruction. Pus collects in the renal pelvis and causes distension of the kidney. It can cause kidney failure and sepsis so treat like septic patient
Apart from CT and ultrasound, how can we diagnose that a dilated kidney is due to obstruction?
What is the presentation of ureteric colic?
How can you treat ureteric obstuction?
Decompress if emergency as risk of sepsis and then one of these procedures
How is a pelviureteric junction obstruction usually caused?
- Often congenital but can present at any stage in life or be asymptomatic and found on imaging by hydronephrosis
- Often loin pain worse after heavy fluid intake or alcohol
- Laproscopic pyeloplasty
What is retroperitoneal fibrosis? How can it be caused and how is it treated?
What?: Fibrosis around the aorta that can pull the ureters in and cause an obstruction
Treatment: Need to decompress, exclude malignancy and give immunosuppression
What is the difference between acute and chronic urinary retention?
What is the definition of urinary retention?
- Inability to voluntarily urinate
- Acute urinary retention is the sudden and often painful inability to void despite having a full bladder
- Chronic urinary retention is painless retention associated with an increased volume of residual urine
What are some causes of urinary retention in men and women?
How do we treat acute urinary retention?
- Catheterise and record residual volume first (to relieve pain)
- History
- Exam e.g abdomen, DRE, genitalia
- Urine Dip
- Treat causes like constipation or alpha blocker for prostate issues
How should you treat someone with acute urinary retention due to issues with their prostate?
- Alpha blocker
- TWOC after 1-2 weeks of blocker (trial without catheter)
- If fails do TURP (transurethral resection of prostate)
What is the difference between high and low pressure chronic urinary retention?
How should we manage chronic urinary retention?
High pressure: same as acute e.g catheterise etc, but cannot TURP so need constant catheter
Low pressure: TURP works in 50% but usually intermittent self catheterisation or long term catheter
Monitor overnight for post obstructive diuresis
What is post-obstructive diuresis?
Prolonged urine production for at least two consecutive hours immediately following the relief of urinary retention. Can lead to dehydration and electrolyte imbalance so might need fluids
