Urinary Catheter

A urinary catheter is a thin, flexible tube inserted through the urethra into the bladder to drain urine continuously. It is connected to a sealed collection bag, allowing accurate measurement of urine output without the patient needing to use a toilet. A balloon at the tip, inflated with sterile water after insertion, holds the catheter in place within the bladder. This type is called a Foley catheter and is the most commonly used in hospital settings.In critical care following cardiac arrest, urinary catheterisation is performed routinely as part of post-resuscitation management. Continuous monitoring of urine output is essential because it provides real-time information about kidney perfusion and function. A normal urine output of at least 0.5 millilitres per kilogram per hour indicates adequate renal blood flow. In the post-arrest period, acute kidney injury is a recognised complication, caused by hypoperfusion during the cardiac arrest and the inflammatory response of post-cardiac arrest syndrome. A falling urine output is an early warning sign that prompts review of fluid balance, vasopressor doses and kidney function blood tests.Urinary catheters are also used during and after cardiac surgery, when patients are anaesthetised and unable to manage their own bladder function, and during prolonged procedures where fluid management requires precise monitoring. Outside the intensive care unit, catheters may be needed for patients with urinary retention caused by medications, prostate enlargement or neurological problems.Catheters are associated with a risk of urinary tract infection (catheter-associated UTI, or CAUTI), which is the most common healthcare-associated infection. To minimise this risk, catheters are removed as early as clinically possible, and strict aseptic technique is used during insertion and management. Patients who have had a urinary catheter should be aware that some discomfort or a burning sensation on first passing urine after...