Session 9 Urinary Flashcards
Features of urinary tract obstruction
Can occur at any level
Unilateral or bilateral, complete or incomplete, gradual or acute onset
Increases risk of UTI, reflux and stone formation
Causes of urinary tract obstruction
Causes of urinary retention
Calculi
Pregnancy
Benign prostatic hypertrophy BPH
Recent surgery
Drugs
Urethral strictures
Why does pregnancy cause urinary retention
High levels of progesterone relax muscle fibres in the renal pelvis and ureters and cause a dysfunctional obstruction
Other causes of urinary retention
Pelviureteric junction obstruction
Pelvic masses
Constipation
Inflammation
Tumours
Neurogenic disorders
Neurogenic disorders that impact urinary retention result from
Congenital abnormalities affecting the spinal cord
External pressure on the cord or lumbar nerve roots
Trauma to the spinal cord
What are Calculi
Kidney stones
Hard deposits made of minerals and salts that form inside kidneys
Acute vs chronic urinary retention
Acute- painful inability to void, residual volume 300-1500ml
Chronic- painless, may still be voiding, residual volume 300-4000ml
Management of acute urinary retention
Catheterise and record residual urinary volume
History
Examination (abdomen, external genitalia, DRE)
Investigations: Urine dip, Us and Es
Treat any obvious cause e.g. constipation,
BPH- alpha blocker, may trial without catheter after 1-2 weeks
Management of chronic urinary retention
Catheterise and record residual volume
History
Exam
urine dip, Us and Es
Plan for long term catheterisation or intermittent self-catheterisation. Wouldn’t attempt TWOC
Types of chronic urinary retention
High pressure: abnormal U and Es, hydronephrosis, repeat episodes = permanent renal scarring and CKD
Low pressure: Normal renal function, no hydronephrosis
what is post-obstructive diuresis
Following resolution of urinary retention through catheter, kidneys can often over-diurese
Leads to worsening AKI. Monitor urine output for 24hrs post catheterisation
Patients with high urine volumes should be supported with IV fluids
What is Diuresis
Losing large amounts of water
What is hydronephrosis
Dilation of the renal pelvis and calyces due to obstruction at any point in the urinary tract causing increased pressure and blockage
Unilateral - upper urinary tract obstruction
Bilateral- lower urinary tract obstruction
Consequences of hydronephrosis
Progressive atrophy of the kidney develops, the back pressure from the obstruction is transmitted to the distal parts of the nephron
GFR declines, if bilateral, renal failure
Hydronephrosis and Hydroureter anatomy
Obstruction at the pelviureteric junction causes
Hydronephrosis
Obstruction at the ureter causes
Hydroureter, eventually leading to hydronephrosis
Obstruction of the bladder neck/urethra causes
Bladder distension, hypertrophy, eventually hydroureter and hence hydronephrosis
Features of acute ureteric obstruction
Results in renal colic
Usually caused by calculus- can be due to blood clots or sloughed papilla
Usually unilateral
Leads to acute renal failure if bilateral (presents as Anuria or oliguria)
Pyonephrosis can develop- infected, obstructed system
Why does GFR decline in hydronephrosis
So much fluid in Bowman’s capsule = pressure bigger than capillaries
Fluid pushed from nephron back into capillaries
What is a sloughed papilla
Filling defect in collecting system and ureter
Renal pyramid falls down and blocks urine
What is Pyonephrosis
Infected, obstructed kidney
Urological emergency
Failure to promptly decompress may lead to death from sepsis and permanent loss of renal function
Diagnosis of upper urinary tract obstruction
CT or USS- show structure not function
Diuretic Renography (MAG3) is a functional test
How do you drain upper urinary tact
Nephrostomy
JJ stent
Features of Urolithiasis (urinary Calculi)
10% of population, more common in men and Caucasians
Dehydration = predisposing factor
High recurrence rate 60-80%
Kidney stones form
Anywhere in urinary tract.
3 common sites:
- Pelviureteric junction
- Pelvic brim
- Vesicoureteric junction
Diagnosis of kidney stones
CT scan of kidneys, ureter and bladder
Compositions of urinary Calculi
5 types
- Calcium Oxalate stones (most common)
- Mixed calcium phosphate and calcium oxalate stones
- Magnesium ammonium phosphate stones
- Uric acid stones
- Cystine stones
What are calcium oxalate stones associated with
Hyeprcalcemia and primary hyperparathyroidism and hyperoxaluria
What are mixed calcium phosphate and calcium oxalatate stones associated with
Alkaline urine
What are magnesium ammonium phosphate stones associated with
Urea splitting bacteria
What are uric acid stones associated with
Gout and myeloproliferative disorders
What are cystine stones associated with
Patients with inherited cystinuria
Clinical presentation of kidney stone
Depends on site
- Dull continuous ache in loins
- Renal colic
- Strangury
- Recurrent and untreatable UTIs, haematuria or renal failure
- Aasymptomatic
Why do ureteric stones cause classical renal colic
Increase in peristalsis in the ureters in response to the passage of a small stone
Radiated from loin to groin, patient appears sweaty, pale and restless with nausea and vomiting
What is Strangury
The urge to pass something that will not pass
Main stream treatment for urinary stones
Adequate analgesia and a high fluid intake
Urine is Sieved for analysis
Stones of 4-5mm or less usually pass spontaneously
Larger stones might require surgical intervention
Other treatment options for kidney stones
Extracorporeal shock wave lithotripsy- show waves shock Calculi into small pieces which will then pass into urine
Prevention of further stone formation is achieved with a
High fluid intake, correction of any underlying metabolic abnormality
Disorders of the prostate
Where is the prostate gland
Main pathogens for prostatitis
E. coli, proteus and staphylococcus
STI = C trachomatis and Neisseria gonorrhoea
Presentation of acute prostatitis
Inflammation can be focal or diffuse
Malaise, rigours and fever
Difficulty in passing urine, dysuria and perineal tenderness
Rectal examination reveals a soft, tender and enlarged prostate
Why does chronic prostatitis occur
Inadequately treated infection
Some antibodies cannot penetrate the prostate effectively
History of recurrent prostatic and urinary tract infections
Management of chronic prostatitis
Some patients asymptomatic- prevent with no preceding acute phase
Diagnosis confirmed by: histological examination showing neutrophils, plasma cells and lymphocytes
Positive culture from prostatic secretion
What is chronic non-bacterial prostatitis
Most common type of prostatitis, results in enlargement of the prostate
Often no history of recurrent UTIs
Usually pathogen = C trachomatis (sexually active men affected)
Fibrosis as a result of chronic inflammation
What does this show
Chronic non-bacterial prostatitis
Fibrosis as a result of chronic inflammation
What is BPH
Non-neoplastic enlargement of the prostate gland, can lead to bladder outflow obstruction
Detectable in nearly all men over 60
Cause unknown but may be related to male sex hormones (testosterone)
Presentation and examination for BPH
Enlarging prostate gland compresses on the prostatic urethra
Men present with obstructive lower urinary tract symptoms:
- Difficulty or hesitancy in starting to urinate
- A poor stream
- Dribbling post micturition
- Frequency and nocturia
Digital rectal examination for the prostate, which is firm, smooth and rubbery
Untreated BPH presentation
Acute urinary retention + distended and tender bladder- desperate urge to pass urine
Or
Progressive bladder distension- chronic painless retention and overflow incontinence
Can lead to bilateral upper tract obstruction and renal impairment with the patient presenting in CKD
Treatment for BPH
Alpha blockers, relax smooth muscle at bladder neck and within prostate
Finasteride (5a-reductase inhibitor)
Surgery- transurethral resection of the prostate TURP
How does Finasteride work
Prevents the conversion of testosterone to the more potent androgen dihydrotestosterone
