![Ultrasound Scan ND 013](https://upload.wikimedia.org/wikipedia/commons/d/dd/Ultrasound_Scan_ND_013.jpg)
In
urology
Urology (from Greek οὖρον ''ouron'' "urine" and '' -logia'' "study of"), also known as genitourinary surgery, is the branch of medicine that focuses on surgical and medical diseases of the urinary-tract system and the reproductive org ...
, a Foley catheter (named for
Frederic Foley, who produced the original design in 1929) is a flexible tube that a clinician passes through the
urethra
The urethra (from Greek οὐρήθρα – ''ourḗthrā'') is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males. In human females and other primates, the urethra c ...
and into the
bladder
The urinary bladder, or simply bladder, is a hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination. In humans the bladder is a distensible organ that sits on the pelvic floor. Urine enters ...
to drain
urine
Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra.
Cellular ...
. It is the most common type of
indwelling urinary catheter.
The tube has two separated channels, or
''lumens'', running down its length. One lumen, open at both ends, drains
urine
Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra.
Cellular ...
into a collection bag. The other has a valve on the outside end and connects to a
balloon
A balloon is a flexible bag that can be inflated with a gas, such as helium, hydrogen, nitrous oxide, oxygen, and air. For special tasks, balloons can be filled with smoke, liquid water, granular media (e.g. sand, flour or rice), or light so ...
at the inside tip. The balloon is inflated with sterile
water
Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...
when it lies inside the bladder to stop it from slipping out. Manufacturers usually produce Foley
catheter
In medicine, a catheter (/ˈkæθətər/) is a thin tubing (material), tube made from medical grade materials serving a broad range of functions. Catheters are medical devices that can be inserted in the body to treat diseases or perform a surgi ...
s using
silicone or coated natural
latex
Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latexes are found in nature, but synthetic latexes are common as well.
In nature, latex is found as a milky fluid found in 10% of all flowering plants (angiosperms ...
. Coatings include
polytetrafluoroethylene,
hydrogel, or a silicon
elastomer – the different properties of these surface coatings determine whether the catheter is suitable for 28-day or 3-month indwelling duration.
![Section cut - Foley cath](https://upload.wikimedia.org/wikipedia/commons/5/55/Section_cut_-_Foley_cath.jpg)
Foley catheters should be used only when indicated, as use increases the risk of catheter-associated
urinary tract infection
A urinary tract infection (UTI) is an infection that affects part of the urinary tract. When it affects the lower urinary tract it is known as a bladder infection (cystitis) and when it affects the upper urinary tract it is known as a kidne ...
(UTI) and other adverse effects. While female sex is generally recognised as a risk factor for UTIs, the differences in biological sex are reduced or even diminished while carrying catheters.
History
The name comes from the designer,
Frederic Foley, a surgeon who worked in
Boston, Massachusetts in the 1930s.
His original design was adopted by
C. R. Bard, Inc. of
Murray Hill, New Jersey
Murray Hill is an unincorporated community located within portions of both Berkeley Heights and New Providence, located in Union County in northern New Jersey, United States.
It is the longtime central location of Bell Labs (part of Nokia s ...
, who manufactured the first prototypes and named them in honor of the surgeon.
Types
Foley catheters come in several types:
* ''Coudé'' (French for elbowed) catheters have a 45° bend at the tip that facilitates easier passage through an enlarged
prostate
The prostate is both an accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation. It is found only in some mammals. It differs between species anatomically, chemically, and phys ...
.
* ''Councill tip'' catheters have a small hole at the tip so they can be passed over a wire.
* ''Three-way'', or ''triple lumen'' catheters have a third channel used to infuse sterile saline or another irrigating solution. These are used primarily after surgery on the bladder or
prostate
The prostate is both an accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation. It is found only in some mammals. It differs between species anatomically, chemically, and phys ...
, to wash away blood and blood clots.
Sizes
The relative size of a Foley catheter is described using
French units (F). Alternatively, the size of a 10 F catheter might be expressed as 10 Ch (Charriere units – named after a 19th century French scientific instrument maker,
Joseph-Frédéric-Benoît Charrière
Joseph-Frédéric-Benoît Charrière (March 19, 1803 – April 28, 1876) was a Swiss-born French manufacturer of surgical instruments.
Charrière was born in Cerniat, in the Canton of Fribourg, Switzerland. He moved to Paris at age 13, and was ...
). The most common sizes are 10 F to 28 F. 1 F is equivalent to 0.33 mm = .013" = 1/77" of diameter. Foley catheters are usually color coded by size with a solid color band at the external end of the balloon inflation tube, allowing for easy identification of the size. Note: Colors for French sizes 5, 6, 8, 10 may vary significantly if intended for pediatric patients. Color for French size 26 may also be pink instead of black.
Medical uses
Urinary tract
Indwelling urinary catheters are most commonly used to assist people who cannot urinate on their own.
[, which cites
*
*
*
*
*
*
* ] Indications for using a catheter include providing relief when there is
urinary retention
Urinary retention is an inability to completely empty the bladder. Onset can be sudden or gradual. When of sudden onset, symptoms include an inability to urinate and lower abdominal pain. When of gradual onset, symptoms may include loss of bladd ...
, monitoring urine output for critically ill persons, managing urination during surgery, and providing
end-of-life care.
Foley catheters are used during the following situations:
* On patients who are
anesthesized or
sedated for surgery or other medical care
* On
comatose patients
* On some
incontinent patients
* On patients whose prostate is enlarged to the point that urine flow from the bladder is cut off
* On patients with acute urinary retention
* On patients who are unable due to paralysis or physical injury to use either standard toilet facilities or urinals
* Following urethral surgeries
* Following
ureter
The ureters are tubes made of smooth muscle that propel urine from the kidneys to the urinary bladder. In a human adult, the ureters are usually long and around in diameter. The ureter is lined by urothelial cells, a type of transitional epit ...
ectomy
* On patients with kidney disease whose urine output must be constantly and accurately measured
* Before and after
cesarean section
Caesarean section, also known as C-section or caesarean delivery, is the surgical procedure by which one or more babies are delivered through an incision in the mother's abdomen, often performed because vaginal delivery would put the baby or ...
* Before and after
hysterectomy
* On patients who have had
genital
A sex organ (or reproductive organ) is any part of an animal or plant that is involved in sexual reproduction. The reproductive organs together constitute the reproductive system. In animals, the testis in the male, and the ovary in the female, a ...
injury
* On
anorexic
Anorexia nervosa, often referred to simply as anorexia, is an eating disorder characterized by low weight, food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin. ''Anorexia'' is a term of Gre ...
patients who are unable to use standard toilets due to physical weakness and whose urine output must be constantly measured
* On patients with
fibromyalgia who cannot control their bladder
* On patients who have severe skin impairment and/or breakdown
Cervical
A Foley catheter can also be used to ripen the
cervix during
induction of labor
Labor induction is the process or treatment that stimulates childbirth and delivery. Inducing (starting) labor can be accomplished with pharmaceutical or non-pharmaceutical methods. In Western countries, it is estimated that one-quarter of pregnan ...
. When used for this purpose, the procedure is called ''extra-amniotic saline infusion''.
In this procedure, the balloon is inserted behind the cervical wall and inflated, for example with 30-80 mL of saline.
[ The remaining length of the catheter is pulled slightly taut and taped to the inside of the woman's leg. The inflated balloon applies pressure to the cervix as the baby's head would prior to labor, causing it to dilate. As the cervix dilates over time, the catheter is readjusted to again be slightly taut and retaped to maintain pressure. When the cervix has dilated sufficiently, the catheter drops out.
]
Other
They are also used in cases of severe epistaxis
A nosebleed, also known as epistaxis, is bleeding from the nose. Blood can flow down into the stomach, and cause nausea and vomiting. In more severe cases, blood may come out of both nostrils. Rarely, bleeding may be so significant that low bl ...
(nosebleed) to block blood from freely flowing down the nasal passage into the mouth.
Foley catheters are also used in abdominal surgery.
Contraindications
Indwelling urinary catheters should not be used to monitor stable people who are able to urinate or for the convenience of the patient or hospital staff. Urethral trauma is the only absolute contraindication to the placement of a urinary catheter. Examination findings such as blood at the urethral meatus, or a high riding prostate necessitate a retrograde urethrogram prior to insertion.
In the United States, catheter-associated urinary tract infection is the most common type of hospital-acquired infection
A hospital-acquired infection, also known as a nosocomial infection (from the Greek , meaning "hospital"), is an infection that is acquired in a hospital or other health care facility. To emphasize both hospital and nonhospital settings, it is so ...
. While UTIs are generally more common among females, the risk factor associated to anatomy is reduced while carrying catheters, some studies even showing no significant differences between the sex. Indwelling catheters should be avoided when there are alternatives, and when patients and caregivers discuss alternatives to indwelling urinary catheters with their physicians and nurses then sometimes an alternative may be found. Physicians can reduce their use of indwelling urinary catheters when they follow evidence-based guidelines for usage, such as those published by the Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention (CDC) is the national public health agency of the United States. It is a United States federal agency, under the Department of Health and Human Services, and is headquartered in Atlanta, Georgi ...
.
Adverse effects
All catheterised bladders become colonised with bacteria within 24 hours. This is not an infection and is very poorly understood by clinicians. Whilst the presence of a catheter does increase the incidence of bloodstream infections secondary to a urinary origin, there is a huge amount of unnecessary, and likely harmful, antimicrobial prescribing on the basis of detection of asymptomatic bacteriuria. The industry is moving to silver-coated catheters in an attempt to reduce the incidence of urinary tract infection
A urinary tract infection (UTI) is an infection that affects part of the urinary tract. When it affects the lower urinary tract it is known as a bladder infection (cystitis) and when it affects the upper urinary tract it is known as a kidne ...
s, although there is limited evidence of efficacy. An additional problem is that Foley catheters tend to become coated over time with a biofilm
A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular ...
that can obstruct the drainage. This increases the amount of stagnant urine left in the bladder, which further contributes to urinary tract infections. When a Foley catheter becomes clogged, it must be flushed or replaced. There is currently not enough adequate evidence to conclude whether washouts are beneficial or harmful.
There are several risks in using a Foley catheter (or catheters generally), including:
* The balloon can break as the healthcare provider inserts the catheter. In this case, all balloon fragments must be removed.
* The balloon might not inflate after it is in place. In some institutions, the healthcare provider checks the balloon inflation before inserting the catheter into the urethra. If the balloon still does not inflate after placement into the bladder, it is discarded and replaced.
* Urine stops flowing into the bag. The healthcare provider checks for correct positioning of the catheter and bag, or for obstruction of urine flow within the catheter tube.
* Urine flow is blocked. The Foley catheter must be discarded and replaced.
* The urethra begins to bleed. The healthcare provider monitors the bleeding.
* Catheterization introduces an infection into the bladder. The risk of bladder or urinary tract infection increases with the number of days the catheter is in place.
* If the balloon is opened before the Foley catheter is completely inserted into the bladder, bleeding, damage and even rupture of the urethra can occur. In some individuals, long-term permanent scarring and strictures of the urethra occur.
* Defective catheters may be supplied, which break in situ. The most common fractures occur near the distal end or at the balloon.
* Catheters can be pulled out by patients while the balloon is still inflated, leading to major complications or even death. This may occur when patients are mentally impaired (e.g. they have Alzheimer's) or are in a mentally altered state (e.g. they are coming out of surgery).
References
Sources
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{{Health care
Catheters
Urologic procedures