Urinary Catheters

Background

Urinary catheters are used in the inpatient and outpatient settings to assist in draining the bladder of urine. Indwelling catheters are placed in about 25% of hospitalized patients during their hospital stay. Indwelling catheters (commonly called “Foley catheters”) have been in use since the 1930s. The origin of the word “catheter” comes from ancient Greek word kathiénai , meaning “to thrust into” or “to send down.” There are several forms of catheters including external devices (e.g., condom catheters), catheters used intermittently (e.g., “straight cath”), or catheters that remain in the bladder (e.g., indwelling urethral catheters or suprapubic catheters). There are two forms of indwelling catheters: 1) Foley catheters that are typically inserted through the urethra into the bladder and 2) suprapubic catheters that are surgically placed through the abdomen into the bladder.

How to Use It

Urinary catheters are used for a variety of indications and based on the indication, used for varying lengths of time. About 70% to 80% of hospital-acquired urinary tract infections (UTIs) are catheter-associated UTIs. To prevent potential complications and catheter-associated infections, catheters should only be placed in the appropriate patients and should be removed as soon as medically feasible. A Foley catheter should be inserted as aseptically as possible to prevent potential infectious complications. Long-term catheter use is classified as being in place more than 30 days.

Catheters historically have been made from latex, but are more recently being made with silicone due to adverse effects from latex. Foley catheters are typically approximately 400 mm in length and have two channels, one for drainage of urine and another to allow the balloon at the end of the catheter to be inflated to keep the catheter anchored within the bladder. Some catheters have a third channel that can be used for continuous bladder irrigation. Coudé or biCoudé catheters are curved and designed to decrease risk of urethral trauma during insertion. The curved tip of the catheter has holes in the end to allow urine to flow through the catheter. The catheter can be connected to tubing that can then be attached to a collection device so that urine can be measured or collected.

Urinary catheters can be external, as with a condom catheters, or more invasive, as with catheters used intermittently or indwelling and suprapubic catheters. There are advantages and disadvantages to each type of catheter.