A Foley catheter is a sterilized, thin tube — most often made of latex rubber — that is inserted into the urethra to catch urine. The catheter can be used in patients who are undergoing surgery or in cases of urinary incontinence. When the medical device is used, typically in a hospital or medical setting, it is usually inserted by trained personnel. There are risks that can be associated with the use of a Foley catheter, including possible infection of the urethra, infection of the bladder and blocked urine flow.
The Foley catheter is named for its inventor, Frederic Foley — a surgeon who came up with the device while a medical student. It was created with three important elements, the balloon, the drainage tube, and the bag. The balloon is typically made in 5 cc or 30 cc sizes, these numbers refer to the amount of sterile water the balloon will hold once inserted into the bladder.
The drainage tube of a Foley catheter is measured based on French units. The sizes range from 10 F to 28 F, with other sizes being less popular. One French unit measures about 0.013 inches (0.33 millimeters). The size needed for insertion into the urethra for urinary catheterization is often determined by the size of the urethra opening.
The Foley catheter bag is attached to the end of the drainage tube to catch the contents of the bladder. Once the bag is full, the bag must be removed and replaced or emptied. If the bag is left full for an extended period of time, an infection of the bladder could occur, as the urine will no longer be able to drain into the bag.
Once the Foley catheter is inserted into the urethra, the drainage tube will be fed into the body until the tip of the tube has reached the bladder. Sterile water is pushed into a tube located next to the drainage port. This sterile water fills the balloon at the end of the tubing to hold the catheter in place.
There can be risks associated with Foley catheter insertion. If a sterile environment is not established before insertion, the catheter could carry bacteria into the urethra. Once the bacteria are present, a urinary tract infection, or UTI, could occur.
Foley catheterization is not only used for draining the bladder. In some instances, the catheter can be fed through the cervical opening during labor to place pressure on the cervix. This pressure can result in a cervix that ripens more quickly, facilitating delivery.