Urinary Retention

Question 1

What is acute urinary retention (AUR)?

Answer 1

Acute urinary retention (AUR) describes a symptomatic inability to completely empty the bladder.

Question 2

What are the clinical features of AUR?

Answer 2

• Little or no urine passed in the post-operative period
• A sensation of needing to void, without being able to micturate
  
  • The retention of urine may be painless in patients with previous chronic urinary retention
• A suprapubic mass that is dull to percussion

Question 3

What are the common causes of AUR?

Answer 3

Patients presenting with urinary retention should be assessed for any underlying causes. Common causes for acute retention post-operatively include uncontrolled pain, constipation, infection or anaesthetic agents (e.g. spinal or epidural use)

Question 4

What are the risk factors for AUR?

Answer 4

• Age >50yrs
• Male gender
• Previous retention
• Type of surgery
  
  • Including pelvic or urological surgery
• Anaesthetic type (spinal or epidural)
• Neurological or urological co-morbidities
• Medication (e.g. antimuscarinics, alpha agonists, opiates)

Question 5

What investigations should be ordered for AUR?

Answer 5

Together with a thorough clinical assessment, the most important investigation is the ultrasonic bladder scan to identify the post-void residual urine volume.

Check for any potential underlying reversible causes and that there is adequate pain control. Check the patient has a stable renal function (as worsening renal function may suggest a high-pressure retention that is impacting renal function).

Question 6

Briefly describe the management of AUR

Answer 6

A conservative approach may be taken in many patients; the majority of post-operative urinary retention will resolve spontaneously given time and withdrawal of any causative agents.

In those that do not resolve, any significant retention will require catheterisation (at least overnight). Patients can have their catheter removed shortly after (often termed a Trial Without Catheter (TWOC)).

For those that fail their TWOC and re-enter retention, a new catheter should be reinserted and patients for repeat TWOC in 1-2 weeks in the community. Importantly, make sure to re-assess any potential reversible causes why the patient may have failed their TWOC that can be addressed