Catheters

A catheter is a flexible tube inserted into the body to drain fluids, deliver medications, or access the body for procedures. Catheters are used briefly during procedures or for longer-term therapy and are classified by purpose, duration, and insertion site, such as urinary, vascular, or gastrointestinal catheters.

Urinary catheters include indwelling Foley catheters with a retention balloon for bladder drainage, and intermittent catheters used for short-term drainage. Suprapubic catheters traverse the abdominal wall into the bladder. Vascular catheters include peripheral venous lines, midline catheters, central venous catheters (non-tunneled, tunneled, or implanted ports), and arterial catheters for access, monitoring, or sampling. Other catheters provide dialysis access (peritoneal dialysis catheter) or drainage (nephrostomy tube).

Catheters are made from latex, silicone, or polyurethane. Sizes are expressed in French units; many have features such as retention balloons, multiple lumens, side holes, or radiopaque markers.

Complications include infection, blockage, dislodgement, trauma to insertion sites, thrombosis, and encrustation. Risk increases with duration of use. Prevention emphasizes aseptic insertion, closed drainage systems when possible, regular care, securement, and prompt removal when no longer needed.

Catheters are common in hospitals, long-term care, and some home settings, with guidelines aimed at balancing therapeutic benefit against infection and mechanical risks. See also urinary catheterization and central venous catheterization.