MD Notes

creation date: 2026-04-29 16:10
tags: Interventions

Urinary Catheterization

Background

Relevant Anatomy and Physiology

Urine is produced in the kidneys which drain through the ureters to the bladder. The bladder’s walls consist of smooth muscle known as the detrusor muscle and contraction results in emptying of the bladder during voiding.

Sensation of bladder filling occurs around 100-150 mL. A desire to void occurs at 200-300 mL and a marked feeling of fullness at 400-500 mL.

Over-distension of the bladder can result in pyelonephritis, hydronephrosis, and eventually renal failure.

Micturition is prevented by contraction of external urethral sphincter, which is under voluntary control, innervated by nerves originating from the sacral area.

Indications

Intermittent catheterization

  • Collection of sterile urine sample
  • Provide relief of discomfort from bladder distention (bladder decompression)
  • Measure residual urine
  • Management of patients with spinal cord injury, neuromuscular degeneration, or incompetent bladders

Short-term indwelling catheterization

  • Post surgery and in critically ill patients to monitor urinary output
  • Prevention of urethral obstruction from blood clots with continuous or intermittent bladder irrigations Instillation of medication into the bladder
  • Surgical procedures involving pelvic or abdominal surgery repair of the bladder, urethra, and surrounding structures
  • Urinary obstruction (eg. enlarged prostate), acute urinary retention

Long-term indwelling catheterization

  • Refractory bladder outlet obstruction and neurogenic bladder with urinary retention
  • Prolonged and chronic urinary retention
  • To promote healing of perineal ulcers where urine may cause further skin breakdown

Risks

  • Urethral trauma and bleeding from inappropriate catheter size or use of force
  • Urinary tract infections related to poor sterile technique or long-term catheterization
  • Bladder spasms and pain

Preparation

Catheter Sizes and Types

Catheter sizes are described by the French scale which represents the outer diameter of the catheter. 3Fr = 1mm.

Catheter types include:

  • Straight-single use
  • 2-way Foley catheter (retention catheters) - has inflatable balloon, and 2-lumens (1 for drainage, 1 for fluid/medication)
  • Curved or Coude - curved tip used for older male patients with enlarged prostates
  • 3-way Foley catheter - third lumen allows for flush, medication, and drainage

Catheter Selection

Choosing the appropriate catheter depends on:

  • Size of the patient’s urethral canal
  • Expected duration of catheterization (eg. intermittent or indwelling)
  • Allergies to latex or plastic
  • Indications for catheterization (ie. clot retention, child, bladder instillation)

For pediatric:

  • 5, 6, 8, 10 Fr, or even smaller are used depending on urethra size and age of child
  • Rarely indwelling; typically used to obtain sterile urine sample

For adults:

  • Size 12-14 Fr for women draining clear urine
  • Size 14-16 Fr for men draining clear urine
  • Size 16-18 Fr for patients with debris or mucous in their urine
  • Sizes in excess of 18 Fr for patients with hematuria (and 3-way Foley)
  • Size 22 Fr for continuous bladder irrigations (CBI’s)

Equipment

Prior to the procedure, ensure the following are at bedside.

  • Catheterization tray (which includes disposable sterile gloves, drapes, lubricant, cotton balls with container, forceps, prefilled 10cc syringe with sterile water for balloon)
  • Sterile catheter
  • Chlorhexidine 2% aqueous solution
  • Sterile water
  • Catheter-secure device or adhesive tape
  • Urinary drainage bag
  • Medicated lubricant (Urojet)

Procedure

Female Catheterization

Catheterize the patient as follows:

  1. Place the patient in the supine position with the knees flexed and separated and feet flat on the bed, about 60 cm apart
    • If this position is uncomfortable, flex only one knee and keep the other leg flat on the bed, or to spread their legs as far apart as possible
    • A lateral position may also be used for elderly or disabled patients
  2. With the thumb, middle and index fingers of the non-dominant hand, separate the labia majora and labia minora. Pull slightly upward to locate the urinary meatus. Maintain this position to avoid contamination during the procedure.
  3. With your dominant hand, cleanse the urinary meatus, using forceps and chlorhexidine soaked cotton balls. Use each cotton ball for a single downward stroke only
  4. Place the drainage basin containing the catheter between the patient’s thighs
  5. Pick up the catheter with your dominant hand
  6. Insert the lubricated tip of the catheter into the urinary meatus
  7. Advance the catheter about 5 cm, until urine begins to flow then advance the catheter a further 1-2 cm
  8. Attach the syringe with the sterile water and inflate the balloon. It is recommended to inflate the 5cc balloon with 7-10cc of sterile water, and to inflate the 30cc balloon with 30-35cc of sterile water
    • Improperly inflated balloons can cause drainage and leakage difficulties
  9. Gently pull back on the catheter until the balloon engages the bladder neck

Note: if the catheter slips into the vagina, leave it there to assist as a landmark. Attempt again with another sterile, lubricated catheter. Remove catheter from vagina after drainage starts from correctly placed catheter.

Male Catheterization

Catheterize the patient as follows:

  1. Place the patient in the supine position with legs extended and flat on the bed. Place a sterile drape under the patient’s buttocks and the fenestrated (drape with hole) drape over the penis
  2. Apply water-soluble lubricant to the catheter tip
  3. With your non-dominant hand, grasp the penis just below the glans and hold upright
    • If the patient is uncircumcised, retract the foreskin. Replace the foreskin at the end of the procedure
  4. With your dominant hand, cleanse the glans using chlorhexidine soaked cotton balls. Use each cotton ball for a single circular motion
  5. Place the drainage basin containing the catheter on or next to the thighs
  6. With your non-dominant hand, gently straighten and stretch the penis. Lift it to an angle of 60-90 degrees
    • At this time you may use the urojet to anesthetize the urinary canal, which will minimize the discomfort
  7. With your dominant hand, insert the lubricated tip of the catheter into the urinary meatus
  8. Continue to advance the catheter completely to the bifurcation ie. until only the inflation and drainage ports are exposed and urine flows
    • Tis is to ensure proper placement of the catheter in the bladder and prevent urethral injuries and hematuria that result when the foley catheter balloon is inflated in the urethra
    • If resistance is met during advancement of the catheter: Pause for 10-20 seconds. Instruct the patient to breathe deeply and evenly. Apply gentle pressure as the patient exhales
    • If you still meet resistance, stop the procedure and repeat above steps
  9. Attach the syringe with the sterile water and inflate the balloon. It is recommended to inflate the 5cc balloon with 7-10cc of sterile water, and to inflate the 30cc balloon with 35cc of sterile water.
    • Improperly inflated balloons can cause drainage and leakage difficulties.
  10. Gently pull back on the catheter until the balloon engages the bladder neck
  11. Attach the urinary drainage bag and position it below the bladder level. Secure the catheter to the thigh.  Avoid applying tension to the catheter.

Note: never inflate a balloon before establishing that the catheter is in the bladder and not just in the urethra. If the patient reports discomfort, withdraw the fluid from the balloon and advance the catheter a little further, then re-inflate the balloon.

References

Tools / Guidelines

Additional Reading