An indwelling catheter is a medical device consisting of a flexible, hollow tube inserted into the body to drain urine from the bladder. The term “indwelling” signifies that the device is designed to remain inside the body for an extended period, which can range from a few days to several weeks or months. This continuous drainage helps manage various conditions that interfere with normal bladder function.
What Defines an Indwelling Catheter and Why It Is Used
The main function of an indwelling urinary catheter is to provide an unrestricted path for urine to flow from the bladder into a closed drainage bag. This is necessary when a patient cannot empty their bladder naturally, a condition known as urinary retention. Retention can be caused by obstructions like an enlarged prostate, blood clots, or certain types of surgery.
The catheter is held securely inside the bladder by a small, inflatable balloon located at the tip. After insertion, sterile water is injected through a separate channel to inflate this balloon, preventing the catheter from slipping out. This retention mechanism allows for continuous drainage.
Catheters are used during and following major surgery to ensure the bladder remains empty and to monitor fluid output. They are also necessary for managing severe urinary incontinence when alternatives fail, or to assist in the healing of open wounds, such as sacral pressure ulcers, that require constant dryness.
Key Differences Between Indwelling Catheter Types
Indwelling catheters are differentiated by their insertion site, with the two main types being the Foley catheter and the suprapubic catheter. The Foley catheter, the most common type, is inserted transurethrally (through the urethra into the bladder). This procedure is straightforward and often managed by nursing staff.
The suprapubic catheter involves a minor surgical procedure where the tube is inserted directly into the bladder through a small incision in the lower abdomen, above the pubic bone. This approach is used when the urethra is blocked, damaged, or when long-term catheterization is anticipated and a urethral route is less suitable for comfort or hygiene.
Catheters are manufactured from different materials, such as latex, silicone, or Teflon, with the choice relating to the expected duration of use. Silicone catheters are preferred for longer-term placement due to their lower irritation and resistance to encrustation. Most indwelling catheters are recommended for short-term use, but the specific material and patient need determine the replacement schedule.
Essential Care and Recognizing Complications
Proper care of an indwelling catheter minimizes the risk of infection and maintains patient comfort. The insertion site, whether urethral or suprapubic, should be cleaned daily with soap and water to prevent bacteria from traveling along the tube into the bladder. Consistent hand hygiene is mandatory before and after handling any part of the catheter system.
The closed drainage system must be managed carefully to ensure continuous flow and prevent backflow of urine into the bladder. The collection bag should always be positioned below the level of the bladder to allow gravity to assist drainage and should be emptied when it is about half full. The catheter tubing must be secured to the leg or abdomen to prevent tension or pulling, which can cause trauma to the bladder neck and urethra.
The most common complication is a Catheter-Associated Urinary Tract Infection (CAUTI), which occurs when bacteria colonize the catheter or the urine in the bladder. Signs of a potential CAUTI include fever, chills, cloudy or foul-smelling urine, or pain in the lower abdomen or back. Other issues include blockage, indicated by a lack of urine output or urine leaking around the insertion site, or general discomfort. Any sudden change in urine output, color, or the development of systemic symptoms requires immediate attention from a healthcare provider.