Urinary catheter

At a Urinary catheter it is a medical instrument for passive emptying of the urinary bladder. It is also possible to obtain urine with it.

What is a urinary catheter?

A urinary catheter is understood to be a hose or tube made of plastic. This instrument is used to empty, fill, flush or probe the human urinary bladder. In addition to plastic, the material of the catheter can also consist of silicone, glass, latex or metal.

A urinary catheter is used primarily to drain accumulated urine from the urinary bladder. This is necessary when the affected person is no longer able to empty their bladder on their own. A urinary catheter can be used for both therapeutic and diagnostic purposes.

Urinary catheters have been used since ancient times. The oldest instrument of this type, made of bronze, was found in Pompeii. The late antique doctor Oreibasios (325-403 AD) resorted to a parchment, which he attached with a goose quill. Once inserted into the urethra, this early urinary catheter remained in the urethra for three days, causing the parchment to swell and thereby dilate the urethra.

In the 19th century, urinary catheters were made from rubber. The balloon catheter in use today comes from the US urologist Frederic Eugene Basil Foley (1891-1966), who manufactured it in 1927 and used it as an indwelling catheter.

Shapes, types & types

Urinary catheters can be divided into transurethral disposable or indwelling catheters and suprapubic catheters. Medicine uses indwelling catheters to ensure that urine is permanently drained. Disposable catheters, on the other hand, are used to drain urine once or to make a diagnosis.

A transurethral urinary catheter is inserted into the urinary bladder via the urethra. A distinction is made between transurethral disposable or indwelling catheters. The indwelling catheters are also called indwelling catheters. They have a balloon at their tip and are therefore self-retaining.

Today, indwelling transurethral catheters are basically balloon catheters. They have different shapes at their tips. Depending on how many openings you have, we speak of a 2-way catheter or a 3-way catheter. A 2-way catheter is provided with a channel that drains the urine and a channel through which the balloon is filled. It acts as a permanent drain for the urine.

A 3-way catheter is also known as a flushing catheter and is also equipped with a third channel with which flushing solutions can be introduced. In urology, it is mainly used after transurethral interventions when there is heavy bleeding in the bladder. Flushing can counteract the clotting of the blood within the urinary bladder.

A suprapubic urinary catheter is a catheter that is intended for permanent urine drainage. It differs from transurethral catheters in that it is not inserted through a natural opening. Instead, it enters the bladder via the abdominal wall above the pubic region.

Structure & functionality

The structure and materials of a urinary catheter have changed in the history of the instrument. In the early days, only glass or various metals were used. The doctors later resorted to rubber. Nowadays, silicone, latex or PVC are used instead of rubber. Modern catheters now also have a hydrophilic coating. This increases the gliding ability of the instrument.

Catheters that are used for long-term use can also be equipped with coatings made of diamond-like carbon. This reduces the colonization of germs. Which material is ultimately best suited for the application depends on the length of time the catheter has been in place.

The introduction of a catheter into the urinary bladder must always be sterile. Otherwise there is a risk that harmful germs can settle in the bladder. In the case of a transurethral catheter, the urethral region is disinfected with a mucosal antiseptic. The next step is to insert a lubricant into the urethra. The urinary catheter can then be inserted into the urethra. Once the catheter is at its destination, the existing balloon is filled with sterile water. The insertion of suprapubic catheters must take place under local anesthesia.

Medical & health benefits

A urinary catheter can provide great medical benefits. It is one of the standard methods for both therapeutic and diagnostic procedures. A urinary catheter is always used when the patient is no longer able to urinate on their own. This circumstance can occur, for example, through enlargement of the male prostate, neurogenic voiding disorders, bladder inflammation or inflammation of the urethra, as well as urinary retention caused by drugs.

The use of a urinary catheter is also considered useful if the urethra is injured or if you are confined to bed for long periods. The catheter takes over the drainage of the urine for a certain time. It is also suitable for palliative care patients who no longer have the strength to go to the toilet.

Furthermore, a urinary catheter is used to introduce drugs into the urinary bladder and to flush it. The catheter can also serve useful diagnostic purposes. A catheter can be used to assess the kidney function of patients over a period of 24 hours. An examination of different germs is also possible.

Further examinations with a urinary catheter include checking the residual urine, determining the size of the urethra, measuring the bladder pressure and imaging the urinary tract.