Urinary Tract Obstruction Flashcards
When may a unilateral urinary tract obstruction be clinically silent?
If the other kidney is functioning normally
What are some examples of when a urinary tract obstruction requires urgent treatment?
If the obstruction is bilateral, or there is obstruction with infection
How does an acute upper urinary tract obstruction typically present?
Loin to groin pain
Symptoms of loin pain, renal failure, superimposed infection and polyuria suggest what type of urinary tract obstruction?
Chronic upper urinary tract obstruction
Why does chronic upper urinary tract obstruction cause polyuria?
There is a reduced concentrating ability of the kidney
How does an acute lower urinary tract obstruction typically present?
Acute urinary retention
Overflow incontinence can be a feature of which type of urinary tract obstruction?
Chronic lower urinary tract obstruction
If a patient presents with any signs/symptoms of urinary tract obstruction, what two bedside tests must always be done?
Bloods for U&Es, urine for MC&S
What is the first line imaging modality of choice for someone with a suspected urinary tract obstruction?
Ultrasound
When should a CT scan be arranged for someone with urinary tract obstruction?
If there is hydronephrosis or hydroureter on ultrasound scans
What are the two main treatment options for an upper urinary tract obstruction?
Nephrostomy or ureteric stent
What medication can be used to help reduce the pain associated with a ureteric stent?
Alpha blockers
How is a lower urinary tract obstruction treated?
Insert a catheter and treat the underlying cause if possible
What are the two main causes of urinary retention?
Obstruction, or reduced detrusor muscle power
What are the two main causes of acute urinary retention?
Prostatic enlargement and urethral strictures
What group of medications are a recognised cause of acute urinary retention?
Anti-cholinergic medications
If a patient is in acute urinary retention and fails to void, how should they be treated?
Catheterisation and an alpha blocker (e.g. tamsulosin)
How are patients who are in acute urinary retention as a result of clot retention treated?
3-way catheter and bladder washout
Why should patient’s U&Es always be monitored closely after catheterisation for acute urinary retention?
Risk of post-obstructive diuresis and salt-losing nephropathy
Why may chronic urinary retention lead to renal failure?
Bilateral obstructive nephropathy
Treating the underlying cause is the best way to manage chronic urinary retention. What else can be used to help control the condition, regardless of the underlying cause?
Intermittent self catheterisation
In patients with chronic urinary retention, an episode of acute urinary retention may only be recognised when what symptom develops?
Overflow incontinence
After placing a catheter in someone with acute-on-chronic urinary retention, what may happen with regards to their renal function?
There may be a significant rise in creatinine, but this usually returns to baseline after a few days
If you suspect obstructive uropathy, what imaging investigation should always be requested?
Renal ultrasound
What can be done to try and avoid post-obstructive diuresis in patients who have been catheterised as a result of urinary retention?
Give resuscitation fluids, and then match input with output
What can be done to try and avoid salt-losing nephropathy in patients who have been catheterised as a result of urinary retention?
Give isotonic (1.26%) sodium bicarbonate solution and withhold any nephrotoxic drugs
What type of disorder is idiopathic retroperitoneal fibrosis?
Autoimmune
What type of urinary tract obstruction is caused by retroperitoneal fibrosis?
Progressive, bilateral urinary tract obstruction
What type of malignancy is a recognised secondary cause of retroperitoneal fibrosis?
Lymphoma
Who does retroperitoneal fibrosis typically present in?
Middle aged males
How does retroperitoneal fibrosis typically present?
Vague loin/back/abdominal pain and hypertension
What is the first line imaging test for retroperitoneal fibrosis and what would it show?
Ultrasound- would show dilated ureters and hydronephrosis
If an US scan is suggestive of retroperitoneal fibrosis, what is the next best investigation to do and what would it show?
CT or MRI- would show a peri-aortic mass
How is retroperitoneal fibrosis treated?
Bilateral retrograde stenting
Other than prostatic enlargement, what is another commonly recognised cause of bladder outflow obstruction?
Urethral strictures
How is a urethral stricture causing bladder outflow obstruction usually managed?
Dilatation
BPH causes hyperplasia of which cells of the prostate?
Both stromal and epithelial cells
Which zone of the prostate is typically affected by BPH?
Transitional zone
Is BPH a pre-malignant disease?
No
What investigation can be used to identify incomplete emptying in those with suspected BPH?
Uroflowmetry
What should always be done before a PR exam in someone presenting with suspected prostatic enlargment?
Bloods for PSA
What investigations are done to exclude a malignancy in someone presenting with suspected BPH?
PSA bloods, TRUS +/- biopsy
What is the first line group of drugs for the management of BPH- give an example?
Alpha blockers e.g. tamsulosin
What is the second line group of drugs for the management of BPH- give an example?
5 alpha reductase inhibitors e.g. finasteride
How does tamsulosin work in the treatment of BPH?
Decreases smooth muscle tone of the bladder and prostate
How does finasteride work in the treatment of BPH?
Reduces dihydrotestosterone levels (and hence the size of the prostate)
Finasteride can take up to how long to be effective in the treatment of BPH?
6 months
What are some side effects of finasteride?
Impotence and decreased libido
What is the surgical treatment of choice for bladder outflow obstruction caused by BPH?
Trans-urethral resection of the prostate (TURP)
What happens in the complication of a TURP procedure known as trans-urethral resection syndrome?
Acute hyponatraemia
What is a transient complication that sometimes occurs after a TURP procedure but rarely becomes a persistent problem?
Incontinence
What are some potential complications of a TURP procedure, to do with sexual function?
Impotence and retrograde ejaculation
For how long after a TURP procedure should patients avoid driving and sexual activity?
2 weeks
What complication may be expected in the first 2 weeks following a TURP procedure, and patients should be warned not to worry about?
Haematuria
Initially following a TURP procedure, patients may need to urinate more frequently than usual. How long will it take for the procedure to work and this complication to stop?
6 weeks
