Lecture 16 - Urinary Obstruction And Prostate Disorders Flashcards by Callum Donoher

What are the most common locations for stones obstructing the urinary tract?

Pelvic brim
Pelviureteric junction
Vesicouteric junction

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What is a stag horn calculus?

The calcification/hardening that occurs in the renal pelvis taking on a stag horn shape

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What do urinary obstructions increase the risk of?

UTIs
Urinary Reflux
Stone formation

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What can cause urinary retention?

Calculi (stones)
Pregancy
Benign prostatic hyperplasia
Recent surgery
Drugs
Urethral strictures
Tumours
Neurogenic disorders
Inflammation

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What are some broad types of neurogenic disorders that can cause urinary retention?

Congenital abnormalities affecting spinal cord
External pressure on cord or lumbar nerve roots
Trauma to spinal cord

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How does acute urinary retention present?

What is their residual volume like?

PAIN (cant void)

Residual volume (300ml - 1500ml)

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How does chronic urinary retention present?

What is their residual volume?

PAINLESS

Possible to still be voiding by not completely so can have a large residual volume

300 - 4000ml

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What is acute on chronic?

Have chronic urinary retention but you then get something else casuing acute urinary retention

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How is an acute urinary retention managed?

Catheter is and record residual volume

Hx
Abdo (shouldn’t normally be able to palpate bladder, ext genitalia and Digital Rectal Exam)
Urine dip
U&Es
Treat obvious cause
Give alpha blockers if BPH

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How is chronic urinary retention managed?

Catheter is and record residual volume
Hx
Exam
Urine dip
U+Es

Often long term catheterisation

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Why are U+Es abnormal (urea + electrolytes) when a patient has hydro nephrosis in chronic urinary retention?

Kidney can’t function properly so things like K+ may build up

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How does a high pressure chronic urinary retention present differently to a low pressure chronic urinary retention?

High pressure:
-abnormal U+Es (hydronephrosis)
-repeat episodes can causes permanent renal scaring and CKD

Low pressure:
-normal renal function
-no hydronephrosis

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What are some questions you may ask a patient with urinary retention?

Last void
Does it feel like a complete
Any pain
Fluid intake
Stream (hesitant flow, dribble)

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What is a potential complication of catheterising a patient with urinary retention?

Post-obstructive diuresis

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What is post-obstructive diuresis?

After a patient with urinary retention is catheterised the kidney can excreted excessive amounts of water which can worsen an AKI

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Why can a patient with post-obstructive diuresis worsen an AKI?

More electrolytes are lost in the excess water they’ve lost

Can lead to hypovolaemia

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How should post-obstructive diuresis be managed?

Urine output monitored for 24hrs post catheterisation

IV fluids if high urine volumes

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What is hydronephrosis?

Dilation of renal pelvis and calyces due to an obstruction at anal point along the urinary tract causing increased pressure and blockage

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Where is the obstruction usually with a unilateral hydronephrosis?

Upper urinary tract obstruction like ureter of the kidney

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Where is the obstruction usually with a bilateral hydronephrosis?

Obstruction in lower urinary tract (e.g prostate)

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What happens to GFR in hydronephrosis?

Declines

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What causes GFR to decline in hydronephrosis of the kidney?

The hydrostatic pressure in the Bowmanns capsule is increased
This acts against the filtration from the glomerulus decreasing the GFR

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How can Hydronephrosis lead to an AKI?

Kidney progressively undergoes atrophy due to the back pressure of the obstruction being transmitted to the distal parts of the nephron

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Look at the last slide image labelled 1:

What is indicated by the CT scan?

Right hydronephrotic kidney

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When can a patient with hydronephrosis go into renal failure?

With bilateral hydronephrosis

What is hydroureter?

Urine accumulation in the ureter due to an obstruction

What occurs if theres an obstruction at the pelviureteric junction?

Hydronephrosis without hydroureter

What occurs if theres an obstruction at the ureter junction?

Hydroureter which then develops into hydronephrosis

What occurs if there’s an obstruction at the neck of the bladder/urethra?

Bladder distension/hypertrophy Leads to hydroureter Then hydronephrosis

What sort of pain does acute uteric obstruction cause?

Renal colic

What is renal colic pain?

Pain that occurs when the smooth muscle of the ureter contracts

What usually causes acute ureteric obstruction?

Calculus (stones) Blood clots Slough papillae

What happens if theres a bilateral acute ureteric obstruction?

Acute renal failure (Presents as Anuria or oliguria) Can get pyonephrosis

What is pyonephrosis?

When an obstructed kidney becomes infected

Why is pyonephrosis a urological emergency?

Failure to decompress may lead to death from sepsis and permanent loss of renal function

How can you diagnose an upper urinary tract infection?

CT Ultrasound Diuretic renography (radio opaque tracer given which then gets taken up by the kidney then monitored, a diuretic is then given)

Go to last slide and label the 4 graphs: Which one indicates normal, obstructed, dilatation + non obstructed and partially obstructed?

1 = normal 2 = obstructed 3 = dilated, non-obstructed 4 = partially obstructed

What are 2 ways to drain the upper urinary tract?

Nephrostomy (into renal pelvis) JJ Stent (passed up urethra all way to renal pelvis)

What is nephrostomy?

When a catheter is directly inserted into the kidneys to drain urine into a nephrostomy bag

What is a JJ Stent?

A urethral stent inserted through the urethra to the ureter inserting into the kidney

What is urolithiasis?

Formation of urinary calculi

What is a risk factor for urolithiasis/urinary calculi?

Men Caucasian Dehydration (HIGH CONC URINE)

Where are the 3 most common sites for urine stones?

Pelviureteric junction Pelvic brim Vesicoureteric junction

How do you diagnose kidney stones/urinary calculi?

CT of kidneys, ureters and bladder

What are the types of calculi? What is the most common type?

Most common = Calcium Oxalate stones Uric acid stones (associated with gout and myelproliferative disorders) Cystine stones (inherited cystinuria) Mg Ammonia PO4(3-) stones Mixed calcium phosphate and calcium oxalate stones

What are the most common calcium oxalate stones associated with? (Blood levels)

Hypercalcaemia And]primary hyperparathyroidism since increases Ca2+ and phosphate levels

How do renal stones present?

Depends on site oof stone Continous dull ache in loins Ureteric stones = renal colic Bladder stones cause strangury Recurrent and unstable UTIs, Haematuria or renal failure Asymptomatic

What is meant by renal colic experience with ureteric stones?

Pain experienced with peristalsis in ureters Radiates from loin to groin Patient sweaty, apple and restless with nausea and vomiting

How are urinary calculi treated? (Urinary stones)

Analgesia High fluid intake Urine sieved for analysis Large stones surgery

What type of diuretic can be given to help with Urinary calculi by reducing urinary Ca2+ levels?

Thiazide diuretics

How do thiazide diuretics work to help urinary calculi?

Reduces urinary calcium levels BLOCKS Na+/Cl- symporter in DCT Less Na+ moved into DCT cell Na+/Ca2+ antiporter on basolateral membrane works more moving more Na+ into DCT cell from lumen so more Ca2+ moved into cell from lumen into the vasa recta (less Ca2+ in lumen/urine)

What are some interventional treatments for urinary stones?

Extracorporeeal SHOCKWAVE Lithotripsy Ureteroscopy Percutaneous Nephrolithotomy

What is Extracorporeal Shock Wave Lithotripsy?

Non invasive procedure where shockwaves are sent to the stone causing it to break down into smaller more passible fragments

What is ureteroscopy?

Thin instrument visualisers and access the stones removing them or fragmenting them

What is Percutaneous nepholithotomy?

For larger stones Invasive Small incision needed to access and remove or break down the stones

Where is the prostate located?

Inferior to the bladder

How should a healthy prostate feel?

Semi firm

What is acute prostatitis?

Inflammation of the prostate usually as a result of infection

What are the main pathogens causing acute prostatitis?

E.coli = main Proteus spp Staphylococcus spp Normally caused by UTIs or STis

How does a patient with acute prostatitis present?

General symptoms: -malaise -rigours -fever Local symtoms: -difficult passing urine (location of prostatic urethra) -dysuria -perineal tenderness

What does a Digital Rectal Exam reveal if a patient has acute prostatitis?

Soft, tender and enlarged prostate

What causes Chronic prostatitis?

Inadequately treated infection Since antibodies can’t penetrate the prostate effectively Some can not have acute phase

How do you diagnose chronic prostatitis?

Histological exam showing neutrophils, plasma cells and lymphocytes Positive culture from sample of prostatic secretion

What is the most common type of prostatitis?

Chronic non—bacterial prostatitis

What is the usual cause for chronic non-bacterial prostatitis?

Chlamydia trachomatis

What is seen on histological exam with chronic non bacterial prostatitis?

Fibrosis due to chronic inflammation

What is Benign prostatic hyperplasia?

Non neoplastic enlargement of the prostate gland whihc can eventually obstruct bladder outflow

Who does BPH normally happen to?

Men over 60

What is thought to be the cause of BPH?

Levels of male sex hormones testosterone

What are some obstructive lower urinary tract symptoms of BPH?

Difficulty or hesitancy starting urination Poor stream Dribbling post micturition Frequency and nocturia

How does the prostate feel on digital rectal examination with BPH?

Firm smooth and rubbery

How can a patient present with untreated BPH?

Acute urinary retention Distended and tender bladder Or progressive bladder distension leading to chronic painless retention Bilateral upper tract obstruction and renal IMPAIRMENT causing CKD

What medical treatments are given for BPH?

Alpha blockers Finasteride

What is the function of alpha blockers used to treat BPH?

Relax the internal urethral sphincter and the smooth muscle at the neck of the bladder within the prostate

What is an example of an alpha blocker given to treat BPH?

Tamsulosin

What type of drug is finasteride? How does finasteride treat BPU?

5a REDUCTASE inhibitor Prevents the conversions of testosterone into its more potent androgen for:dihydrotestosterone

What 2 drugs are normally given to treat BPH (Benign Prostatic Hyperplasia)?

Finasteride (5a REDUCTASE inhibitor) Tamsulosin (alpha blocker)

What surgical treatment can be done for BPH?

Transurethral resection of the prostate (TURP) Removes part of prostate giving urethra more space

What is the typical causative organism of a previous UTI infection can lad to chronic non-bacterial prostatitis? How does a culture appear if a semen prostate secretion sample is taken?

Chlamydia trichomatis No bacteria appear on swab/agar