In urinary catheterization, or "cathing" for short, a plastic tube known as a urinary catheter is inserted into a patient's bladder via their urethra. Catheterization allows the patient's urine to drain freely from the bladder for collection, or to inject liquids used for treatment or diagnosis of bladder conditions. The procedure of catheterization will usually be done by a clinician, often a nurse, although self-catheterization is possible as well.

[edit] Catheter types

A Tiemann -type catheter installed for a male doll in an exercise.

Catheters come in several basic designs:^[1]

• A Foley catheter is retained by means of a balloon at the tip which is inflated with sterile water. The balloons typically come in two different sizes: 5 cc and 30 cc. They are commonly made in silicone rubber or natural rubber.
• A Robinson catheter is a flexible catheter used for short term drainage of urine. Unlike the Foley catheter, it has no balloon on its tip and therefore cannot stay in place unaided.
• A Coudé catheter is designed with a curved tip that makes it easier to thread the catheter pass the prostate or obstructions in the urethral canal. A Coudé catheter tip may be provided with a balloon or not.
• An irrigation catheter has a separate lumen to carry irrigation fluid into the bladder. This is useful following endoscopic surgical procedures or in the case of gross hematuria.^[1]
• An external Texas or condom catheter is used for incontinent males and carries a lower risk of infection than an indwelling catheter.^[2]

Catheter diameters are sized by the French catheter scale (F). The most common sizes are 10 F (3.3mm) to 28 F (9.3mm). The clinician selects a size large enough to allow free flow of urine, but large enough to control leakage of urine around the catheter. A larger size can become necessary when the urine is thick, bloody or contains large amounts of sediment. Larger catheters, however, are more likely to cause damage to the urethra. Some people develop allergies or sensitivities to latex after long-term latex catheter use making it necessary to use silicone or Teflon types. Silver alloy coated urinary catheters may reduce infections.^[3]

[edit] Sex differences

In males, the catheter tube is inserted into the urinary tract through the penis. A condom or Texas catheter can also be used. In females, the catheter is inserted into the urethral meatus, after a cleansing using povidone-iodine. The procedure can be complicated in females due to varying layouts of the genitalia (due to age, obesity, Female genital cutting, childbirth, or other factors), but a good clinician should rely on anatomical landmarks and patience when dealing with such a patient. In the UK it is generally accepted that cleaning the area surrounding the urethral meatus with 0.9% sodium chloride solution is sufficient for both male and female patients as there is no reliable evidence to suggest that the use of antiseptic agents reduces the risk of urinary tract infection.^[4]

Common indications to catheterize a patient include acute or chronic urinary retention - (which can damage the kidneys), orthopedic procedures that may limit a patient's movement, the need for accurate monitoring of input and output (such as in an ICU), benign prostatic hyperplasia, incontinence, and the effects of various surgical interventions involving the bladder and prostate.

For some patients the insertion and removal of a catheter causes excruciating pain, so a topical anesthetic is used. Catheterization should be performed as a sterile medical procedure and should only be done by trained, qualified personnel, using equipment designed for this purpose, except in the case of intermittent self catheterization where the patient has been trained to perform the procedure himself or herself. If correct technique is not used there may be trauma to the urethra or prostate (male), urinary tract infection, or a paraphimosis in the uncircumcised male.

[edit] Catheter maintenance

A catheter that is left in place for more than a short period of time is generally attached to a drainage bag to collect the urine. This also allows for measurement of urine volume. There are two types of drainage bags: The first is a leg bag, a smaller drainage device that attaches by elastic bands to the leg. A leg bag is usually worn during the day, as it fits discreetly under pants or skirts, and is easily emptied into a toilet. The second type of drainage bag is a larger device called a down drain that may be used overnight. This device is usually hung on the patient's bed or placed on the floor nearby.

During long-term use, the catheter may be left in place during the entire time, or a patient may be instructed on a procedure for placing a catheter just long enough to empty the bladder and then removing it (known as intermittent self-catheterization). Patients undergoing major surgery are often catheterized and may remain so for some time. The patient may require irrigation of the bladder with sterile saline injected through the catheter to flush out clots or other matter that does not drain.^[5]

[edit] Effects of long term use

The duration of cathetarization can have significance for the patient. Incontinent patients commonly are catheterized to reduce their cost of care. However, long-term catheterization carries a significant risk of urinary tract infection. Because of this risk catheterization is a last resort for the management of incontinence where other measures have proved unsuccessful. Other long term complications may include blood infections (sepsis), urethral injury, skin breakdown, bladder stones, and blood in the urine (hematuria). After many years of catheter use, bladder cancer may also develop.

[edit] Combating infection

Everyday care of catheter and drainage bag is important to reduce the risk of infection.^[6] Such precautions include:

• Cleansing the urethral area (area where catheter exits body) and the catheter itself.
• Disconnecting drainage bag from catheter only with clean hands
• Disconnecting drainage bag as seldom as possible.
• Keeping drainage bag connector as clean as possible and cleansing the drainage bag periodically.
• Use of a thin catheter where possible to reduce risk of harming the urethra during insertion.
• Drinking sufficient liquid to produce at least two liters of urine daily
• Sexual activity is very high risk for urinary infections, especially for catheterized women.

Recent developments in the field of the temporary prostatic stent have been viewed as a possible alternative to indwelling catheterization and the infections associated with their use. ^[7]

[edit] See also

• French catheter scale
• Prostatic stent

[edit] References

[edit] External links

• New England Journal of Medicine Video on Urinary Catheterization