MedSchool: Ace Your OSCEsThe Medical Company
GET - On the App Store
Urinary Catheters
Urinary Catheters

Urinary Catheter Insertion

March 4th, 2023


Urinary catheters are used for a wide variety of indications including to relieve urinary retention, measure urine output and collect urine samples.
Male catheterisation can be more difficult and higher risk than female catheterisation due to the length and course of the male urethra.
  • Indications for catherisation are:
  • Bladder drainage - for relief of acute urinary retention or bladder outlet obstruction
  • Prevention of urinary retention due to clots
  • Measurement of urine output
  • Perioperative use - urologic surgery, prolonged surgery, large volumes of intraoperative infusion or diuretics, intraoperative urine output measurement
  • Urine specimen collection in patients who are unable to voluntarily void
  • To assist in the healing of perineal wounds in incontinent patients
  • Instillation of medications into the bladder
  • Contraindications to catheterisation include:
  • Urethral trauma - e.g. due to pelvic fracture
  • Urethral stricture
  • Recent urologic surgery (men) - discuss with a urologist first
Urinary catherisation is not always appropriate - particularly given the risk of infection while a catheter is in situ. Catheters should not be used to control urinary incontinence, or manage confused patients. Prolonged bed rest is also not an indication for insertion. While catheters are often inserted to allow measuring of urine output, this is generally not required and in fact invasive then hourly urine output measuring is not required.

Equipment and Preparation

  • The following are required for catheter insertion:
  • Choosing a catheter

  • A larger catheter is usually easier - go up a size rather than down if insertion is difficult.
  • There are several types of catheters:
  • Straight, single lumen - for collection of urinary specimens
  • Double lumen (with balloon) - most patients
  • Triple lumen - continuous irrigation for patients with clots or haematuria or post urologic surgery
  • Catheter Size Guide

  • 6-10 French - paediatric patients
  • 12-14 French - most patients
  • 16-20 French - patients with clots or haematuria
  • 22 French (triple lumen) - continuous irrigation for patients with clots or haematuria or post urologic surgery

Catheter Insertion

  • Introduction

  • Preparation

  • Insertion

  • Finishing Up


  • Potential complications of urinary catheterisation include:
  • Traumatic insertion - resulting in haematuria, false passage creation or urethral strictures
  • Urinary tract infection - cystitis, pyelonephritis or sepsis
  • Iatrogenic hypospadiasErosion of the urethral meatus due to downward pressure
  • Bladder stonesParticularly with long-term catheterisation
  • Bladder cancerRate, but long-term catheterisation is a risk factor
  • Traumatic Insertion

  • While inserting an indwelling catheter, it is possible to damage the urethral mucosa or even perforate the urethral wall, creating a false passage.
Clinical features of traumatic insertion include haematuria (blood in the urine bag) or urinary retention due to clots.
This can be prevented by using adequate lubrication, and inserting the catheter gently - don't push too hard against resistance.
  • Urinary Tract Infection

  • Catheterisation, and particularly long-term catheterisation, is associated with infection - this may manifest as cystitis, pyelonephritis or sepsis.
The catheter acts as a bridge for ascension of bacteria into the bladder; and residual urine within the bladder increased the risk of infection. Biofilms may develop which make the infection more difficult to eradicate.
Clinical features of cystitis (bladder infection) include burning around the catheter, the urge to urinate, lower abdominal pain, cloudy or bloody urine, and foul-smelling urine. Pyelonephritis (kidney infection) may manifest with fevers, nausea, vomiting and flank pain.
Catheter-associated UTIs can be prevented by inserting catheters only when clinical indicated; by rationalising the duration of the catheter; and by changing the catheter regularly if it is in long-term.
  • Iatrogenic Hypospadias

  • Erosion of the urethral meatus may occur following catheter insertion in males. This occurs due to continuous downward pressure of a long-term catheter on the meatus. 
This may manifest early with erythema surrounding the meatus, and eventually the mucosa will start to break down and erosion can occur. This may be associated with infection.
This complication can be prevented by fixing the catheter to the lower abdomen, in order to prevent downward pressure.
Next Page
Want more info like this?
  • Your electronic clinical medicine handbook
  • Guides to help pass your exams
  • Tools every medical student needs
  • Quick diagrams to have the answers, fast
  • Quizzes to test your knowledge
Sign Up Now

Snapshot: Initialising...