Technique And Use Of The Foley Catheter

The Foley catheter is a type of flexible catheter that drains urine from the bladder to the outside. For this reason, it is also known as a urinary catheter or a bladder catheter.

The tube is usually made of latex, as this material is more comfortable for patients. However, if the person is allergic to latex, there is another type of plastic that manufacturers use to maintain catheter sterility. This will help prevent infections.

In addition, it should be noted that these catheters are named after Dr. Foley, an American surgeon. As we will explain later, they are often used by patients in the medical world.

How is the Foley catheter designed?

The doctor inserts the Foley catheter through the urethra to reach the bladder. It must therefore be able to adapt to different sizes. There are therefore  a number of different pipes for men, women and children. In addition, there are also different thickness gauges so that they can better adapt to the peculiarities of the anatomy of each patient.

There is a scale that describes the size of the catheters. It is the French scale of Charrière, where one unit corresponds to 33 cm.

The number of Charrière units corresponds to the size of the catheter circumference in millimeters. This means that, using the number of Charrière units (represented by the symbol F), we can know the diameter of the catheter and therefore the urethra.

Despite the large selection of catheters, they all have something in common. They all have a balloon attached to the tube that comes without air. The balloon is the crucial part of the Foley catheter. This part helps the tube to function properly, as it is the only element in the design that prevents the catheter from coming loose.

How to place the Foley catheter?

Before inserting it, the doctor must make sure that the catheter is not defective. Today, the production performs very strict quality controls. Still, it is not uncommon to come across a catheter that has a simple defect.

To check that the catheter is working , the doctor should put some sterile water in the nozzle that is in the balloon. If the balloon begins to swell and no leaks occur, the catheter can be used on the patient.

Remember that the patient’s genitals must be completely clean. Using a little lubricant, the doctor gently inserts the catheter into the urethra. To make it easier to insert the tube into the bladder, you can put some pressure on the stomach by using different breathing maneuvers or by stimulating urination.

Once the tube is inside the bladder, the balloon must be filled to prevent the tube from sliding out. Using a syringe, fill the balloon with air or sterile water using the nozzle with the small valve.

Finally, the catheter valve itself is connected to a bag where the urine is stored. To make the measurement of the volume easier, there are also graduation marks on the bag, usually in millimeters.

What is it used for?

The most common uses of the Foley catheter are:

• Urinary incontinence : This is common in the elderly and in patients with neurological injuries where the nerves responsible for urination are damaged.

• Any situation that prevents complete emptying of the bladder : for example, prostate cancer.
• Patients who have undergone surgery and need to control the volume of urine expelled.

What are the disadvantages?

The main problem when using the Foley catheter is the risk of a urinary tract infection. The catheter is still a foreign body in an area where bacteria can enter from the outside of the genitals into the bladder. One must therefore be careful with the hygiene in this area.

In addition, it is important to prevent the drainage bag from twisting so that the urine flows continuously and does not accumulate in the tube. An easy way to do this is to hold the catheter in place by taping it to the thigh. On the other hand, if the patient is bedridden, the bag can be left under the bed so that the urine flows by gravity.