A bladder catheter is used to drain collected urine from the bladder. It is always necessary when a patient can no longer urinate independently, for example due to a narrowing of the urinary tract or a nerve dysfunction. Read all about the procedure, when it is performed and the risks involved.
What is a Foley catheter?
A bladder catheter is a plastic tube through which urine is drained and then collected in a bag. It usually consists of solid silicone or latex.
A distinction is made between the transurethral catheter and the suprabic catheter. The transurethral bladder catheter is inserted into the bladder via the urethra. The suprapubic bladder catheter, on the other hand, is placed directly into the bladder through a puncture in the abdominal wall.
Furthermore, the catheter types can be distinguished by their tip. Examples of different catheter tips are:
Nelaton catheter (blunt tip, mostly used in women)
Tiemann catheter (conical, curved tip, well suited for difficult catheter systems)
Mercier catheter (similar to the Tiemann catheter)
Stoerer catheter (flexible tip)
The outer diameter of the bladder catheter is given in Charrière (Ch). One Charrière corresponds to about one third of a millimeter. Commonly used diameters for men are 16 or 18 Ch, while catheters between 12 and 14 Ch are usually used for women.
When do you need a bladder catheter?
The urinary catheter is a standard procedure that is used both for therapeutic reasons and for diagnostic purposes.
Bladder catheter for therapy
Basically, the bladder catheter is used when the patient can no longer urinate independently. This can be the case with the following basic diseases:
Neurogenic voiding disorder
Enlargement of the prostate gland
urinary retention due to medication
inflammation of the bladder or urethra
The catheter can also be used temporarily to drain urine when the patient is bedridden or if the urethra has been injured, for example, in an accident or during surgery. For palliative patients who are already too weak to go to the toilet frequently, urine diversion via the bladder catheter is an alternative.
The urinary catheter is also used to flush the bladder or to introduce medication.
Bladder catheter for diagnostic purposes
If the doctor wants to check the kidney function, he can assess the patient’s urine over a period of 24 hours with regard to quantity and concentration. He can also examine the collected urine for various germs.
Other examinations where a bladder catheter can be used are:
-Imaging of the urinary tract (contrast medium injection via the catheter)
-Residual urine control
-Bladder pressure measurement (urodynamics) to check the bladder function
-Determination of the urethral width
How do you place a Foley catheter?
If the doctor or nurse wants to place the urinary catheter, it is important to ensure thorough hygiene and sterile working conditions to prevent infections.
The patient lies in a supine position with her legs spread to one side for the application of the bladder catheter. The doctor or nurse now carefully cleans the genital area with a disinfectant that is especially suitable for the sensitive mucous membranes. Using sterile tweezers, he now grips the catheter tube and coats it with a little lubricant. This way he can easily insert the bladder catheter and push it all the way into the bladder.
If the catheter is correctly positioned in the bladder, urine will immediately flow through the tube. The so-called catheter balloon is then dilated with about five to ten milliliters of distilled water so that the catheter can no longer slip out of the bladder.
Transurethral catheter: Man
For the insertion of the transurethral bladder catheter the patient lies on his back. The doctor covers the genital area sterilely, carefully pulls back the patient’s foreskin and cleans the penis with a disinfectant suitable for the mucous membrane. Using a syringe, he injects five to ten millilitres of a lubricant into the urethra. With gentle pressure, the doctor now slides the bladder catheter over the urethra into the bladder and fixes it there with the catheter balloon.
Suprapubic bladder catheter
After carefully disinfecting the abdominal wall, the doctor covers the patient’s abdomen with a sterile cloth, leaving out the puncture area. After a local anaesthetic, the doctor stabs the abdominal wall with a syringe about two to three centimetres above the pubic bone, about five centimetres deep into the abdominal wall. If he can suck in urine with the syringe, the correct position in the bladder is ensured. However, he usually checks the position and filling level of the bladder again using ultrasound.
Using a special scalpel he then opens the abdominal wall so that he can insert a hollow needle. This already contains the catheter tube. When urine flows through it, the doctor withdraws the hollow needle and fixes the catheter to the abdominal wall with a superficial suture. The exit point is now sterilely connected.
What are the risks of a bladder catheter?
The most important complication when placing a catheter is an infection of the urinary tract. Germs can migrate through the catheter tube and spread in the urinary tract. The doctor calls this an ascending infection, which in the worst case can lead to blood poisoning (sepsis). The longer the catheter is placed, the greater the risk of infection. All the more important is careful catheter hygiene. In addition, when inserting the catheter, there may be an injury to the urethra, which, when it heals, can narrow the urethra.
A suprapubic catheter carries a lower risk of infection. However, in rare cases, the insertion of a suprapubic catheter can result in injury to abdominal organs or vessels.
What do I have to consider with a bladder catheter?
The catheter outlet should be thoroughly cleaned twice a day with water and unperfumed, pH-neutral washing lotion. During cleaning, encrustations and mucus are removed from the exit point with sterile disposable compresses. During this process, the urethra is always “wiped away” so that no bacteria are rubbed into the entry point. In uncircumcised men, the foreskin must be brushed forward again after cleaning.
In order for the urine to flow off optimally, you should neither kink nor pull the catheter tube. Always store the collection bag below the level of the bladder, otherwise there is a risk that the urine will run back over the catheter tube.
With a lying bladder catheter you should make sure that you drink at least 1.5 litres of liquid. To prevent germs, you can also acidify the urine slightly by drinking cranberry or cranberry juice instead of water.
If the doctor wants to remove transurethral bladder catheters, he will drain the distilled water from the small balloon with a syringe at the end of the catheter tube and pull the catheter out through the urethra. An anaesthetic is not necessary for this. To remove the suprapubic bladder catheter, the doctor pulls the stitches of the skin suture and removes the catheter tube.