Urinary Retention

Question 1

What is Acute Urinary Retention?

Answer 1

When a person suddenly (hours) becomes unable to voluntarily pass urine - the commonest urological emergency.

Question 2

Epidemiology of Acute Urinary Retention.

Answer 2

Commoner in men (especially above 60).

Question 3

Aetiology of Acute Urinary Retention.

Answer 3

1. BPH (commonest).
2. Urethral Strictures.
3. Calculi.
4. Cystocoele.
5. Constipation.
6. Masses.
7. Medications e.g. Anticholinergics, TCAs, Antihistamines, Opioids, Benzodiazepines.

Question 4

Clinical Presentation of Acute Urinary Retention (4)

Answer 4

1. Inability to Pass Urine.
2. Lower Abdominal Discomfort.
3. Considerable Pain/Distress.
4. Acute Confusional State.

Question 5

Examination Findings of Acute Urinary Retention (2).

Answer 5

1. Palpable Distended Bladder.

2. Lower Abdominal Tenderness.

Question 6

Investigation of Acute Urinary Retention.

Answer 6

US - Volume More than 300cc.

Question 7

Management of Acute Urinary Retention.

Answer 7

Decompress Bladder via Catheterisation.

Question 8

How can the management be used to investigate Acute Urinary Retention?

Answer 8

1. A volume less than 200cc drained in 15 minutes = no urinary retention acutely.
2. A volume greater than 400cc drained in 15 minutes = catheter should be left in place.

Question 9

Complication of Acute Urinary Retention.

Answer 9

Post-Obstructive Diuresis - loss of medullary concentration-gradient means kidneys increase diuresis so time is taken to re-equilibrate, leading to volume depletion and worsening of any AKI.

Question 10

Clinical Presentation of Chronic Urinary Retention.

Answer 10

Painless and insidious.

Question 11

Clinical Presentation of Acute on Chronic Urinary Retention.

Answer 11

Overflow Incontinence.

Question 12

High-Pressure Retention vs. Low-Pressure Retention.

Answer 12

High-Pressure : Impaired Renal Function and Bilateral Hydronephrosis (due to BOO)
Low-Pressure : Normal Renal Function and No Hydronephrosis.

Question 13

What can occur commonly after catheterisation for chronic urinary retention?

Answer 13

Decompression haematuria - rapid decrease in intravesical pressure.