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Flashcards in Urinary Tract Obstruction Deck (39):
1

What is the definition of acute urinary retention?

Painful inability to void with a palpable and percussible bladder

2

How much do residuals vary in acute urinary retention?

500ml to >1L depending on time lag in seeking medical attention

3

What is the main risk factor for acute urinary retention?

BPO

Can also occur independently of BPO
-(e.g. UTI, urethral stricture, alcohol excess, post-op causes, acute surgical or medical problems)

4

For people with BPO when can acute urinary retention occur?

Spontaneously (i.e. natural progression of BPO)

Triggered by an unrelated event (e.g. constipation, alcohol excess, post-op causes, urological procedure)

5

What is the immediate treatment of acute urinary retention?

Catheterisation (either urethral or suprapubic)

Will feel better straight away

6

What are the complications of catheterisation in acute urinary retention?

UTI

Post decompression haematuria

Pathological diuresis

Renal failure

Electrolyte abnormalites

7

After catheterisation in acute urinary retention what is the next step?

Treat underlying trigger if present.

If no renal failure, start alpha blocker immediately and remove catheter in 2 days (60% will void successfully);
-If fail to void, recatheterise and organise TURP (after 6 weeks)

8

What is the definition of chronic urinary retention?

Painless, palpable and percussible bladder after voiding

9

How much do residuals vary in chronic urinary retention?

patients often able to void but with residuals ranging from 400ml to >2L depending on stage of condition (i.e. wide spectrum)

10

What are the main aetiological factors in chronic urinary retention?

Detrusor underactivity which can be primary (i.e. primary bladder failure) or secondary (i.e. due to longstanding BOO, such as BPO or urethral stricture)

11

How does chronic urinary retention present?

LUTS

Or complications:
-UTI, bladder stones, overflow incontinence, post-renal or obstructuve renal failure) or incidental finding

12

When does overflow incontinence and renal failure occur in chronic urinary retention?

Severe end of spectrum, when bladder capacity is reached and bladder pressure is in excess of 25cm water

(i.e. decompensated chronic urinary retention or acute-on-chronic urinary retention or high pressure chronic urinary retention)

13

When should you treat in chronic urinary retention?

Asymptomatic patiens with low residuals so not necessarily need treatment

Patients with symptoms or complications need treatment (but no role for medical therapy!)

14

What is the immediate treatment in chronic urinary retention?

Catheterisation (either urethral or suprepubic initially, followed by CISC if appropriate)

15

What is CISC?

Clean Intermittant Self Catheterisation

16

What are the complications of catheterisation in chronic urinary retention?

UTI

Post decompression haematuria

Pathological diuresis

Electrolyte abnormalities (hyponatraemia, hyperkalaemia, metabolic acidosis),

Persistant renal dysfunction due to acute tubular necrosis

17

What are the features of pathological diuresis?

Urine output >200ml/hr
+
Postural Hypertension (systolic differential >20mmHg between lying and standing)
+
Weight loss
+
Electrolyte abnormalities

18

How do you manage someone after immediate treatment in chronic urinary retention?

Manage with IV fluids (total input = 90% of output) and monitor closely; liase with renal team
- This is to prevent post-obstructive diuresis

Subsequent treatment is with either long term urethral or suprapubic catheter, CISC or TURP

19

What is Post obstructive diuresis (pathological diuresis)?

Postobstructive diuresis is a polyuric response initiated by the kidneys after the relief of a substantial bladder outlet obstruction. In severe cases this condition can become pathologic, resulting in dehydration, electrolyte imbalances, and death if not adequately treated

20

Chronic urinary retention is further divided into high and low pressure CUR.

What is the difference?

The presence or absence of intrinsic detrusor pressure is what differentiates them.

High-pressure CUR results from an obstruction with the presence of detrusor muscle activity, while low-pressure CUR involves detrusor failure with low intravesical pressure.

This distinction is important, as high detrusor pressure can lead to upper urinary tract damage and present with new-onset hypertension, peripheral edema, or renal dysfunction.

21

How does TURP success in chronic urinary retention compare to acute urinary retention?

Less successful outcome in chronic than fro acute retention; however, patients with high pressure chronic retention have better outcome with TURP than with low pressure chronic retention.

22

What are the two types of urinary tract obstruction?

Upper tract
- i.e. supra-vesical

Lower tract
- i.e. bladder outflow obstruction

23

Where can upper urinary tract obstruction occur?

Pelvi-Ureteric Junction

Ureter

Vesico-Ureteric Junction

24

Where can lower urinary tract obstruction occur?

Bladder neck
Prostate
Urethra
Urethral meatus
Foreskin (e.g. phimosis)

25

What kinds of things may cause upper tract obstruction?

PUJ obstruction (physiological or crossing vessel)

Stone or blood clot

Ureteric tumour (TCC)

Lymph nodes or abdominal mass

bladder tumour

26

What are the symptoms and signs of upper tract obstruction?

Symptoms:
-Pain
-Frank haematuria
-Symptoms of complications

Signs
-Palpable mass
-Microscopic haematuria
-Signs of complications

27

What are the complications of upper tract obstruction?

Infection and sepsis
Renal failure

28

When do you really need to worry about upper tract obstruction and act fast?

Infection
Acute retention
Renal failure

29

What is involved in resiscitation in upper tract obstruction?

ABCs

IV access, bloods, ABG, urine and blood cultures, fluid balance monitoring

IV fluids, broad spectrum antibiotics (if appropriate)

Analgesics

HDU care +/- renal replacement therapy if appropriate

30

What is involved in the emergency treatment of upper tract obstruction?

For unremitting pain or complications

-Percutaneous nephrostomy insertion

OR

-Retrograde stent insertion

(This buys you time for definitive treatment)

31

What is percutaneous nephrostomy insertion?

Percutaneous nephrostomy is an interventional radiology/surgical procedure in which the renal pelvis is punctured whilst using imaging as guidance.

A nephrostomy tube may then be placed to allow drainage.

32

What is a retrograde stent insertion?

A ureteric stent
is a thin plastic tube placed in your ureter
to allow urine to drain freely from your kidney
to the bladder.

Wire up ureter into bladder to feed tube

33

What is the definitive treatment of obstruction in Upper tract obstruction?

Treat underlying cause

e.g. stone
-Uteroscopy and laser lithotripsy +/- basketing or ESWL

e.g. ureteric tumour
-Radical nephro-ureterectomy

e.g. PUJ obstruction
-laparoscopic pyeloplasty

34

How does lower tract obstruction present?

LUTS
-Including urinary incontinence

Acute or chronic urinary retention

Recurrent UTI and sepsis

Frank haematuria

Formation of bladder stones

Renal failure

35

What is involved in resuscitation in lower tract obstrcution?

ABCs

IV access, bloods, ABG, urine and blood cultures, fluid balance monitoring

IV fluids, broad spectrum antibiotics (if appropriate)

Analgesics

HDU care +/- renal replacement therapy if appropriate

36

What investigations can you carry out in upper tract obstruction?

USS renal tract

CT

37

What investigations can you carry out in lower tract obstruction?

Bladder scan

USS renal tract

38

What is the emergency treatment of obstrcution in lower tract obstruction?

For unremitting pain or complications

-Urethral catheterisation

OR

-Suprapubic catheterisation

39

What is the definitive treatment of lower tract obstruction?

Treat underlying cause

e.g. BPE
-TURP

e.g. Urethral stricture
-Optical urethrotomy

e.g. Meatal stensosis
-Meatal dilatation

e.g. Phimosis
-Circumcision