Hospital Medicine

Foley Catheters

I. Problem/Challenge.

Foley catheters are the most widely utilized type of indwelling urinary drainage system. They were designed in the 1930's by the urologist Frederic Foley. Modern Foley catheters have dual lumen tubes, with one lumen dedicated to urinary drainage, and the other used for balloon inflation. The balloon can be filled with air or sterile water (normal saline should be avoided, as crystal formation may prevent balloon deflation). It is inflated after catheterization to help maintain catheter position.

Foley catheters are usually made of latex or silicone rubber. Latex is inexpensive, and if you order a "Foley" in a hospital in the United States, your patient will likely receive a dual lumen latex catheter with a water inflation balloon system. Latex has been associated with urethral inflammation and is susceptible to encrustation. It should be avoided in patients with latex allergies.

Foley catheters are sized according to their outside diameter using the French scale. One French (Fr) equals 0.33mm. They vary in size between 12 Fr (4 mm) and 30 Fr (10 mm). Size 12 Fr is large enough to relieve urinary obstruction in most adults, although practitioners typically choose size 14 to 16 Fr for initial catheterization. Larger diameter catheters may be required for adequate drainage of hematuria or clots. The catheter is typically attached to a drainage bag.

Closed catheter urinary drainage systems reduce the incidence of bacteruria, and have become the standard of care. Pre-connected systems and catheters coated with antimicrobial agents may reduce bacteruria, but have not consistently been shown to reduce the incidence of urinary tract infection.

Other commonly used balloon tipped indwelling urinary catheters include three outlet devices (also known as a "triple lumen catheter" or "three-way Foley") and Coude catheters. Triple lumen catheters have an extra port for bladder irrigation, and are available in large diameters (i.e. 20 to 24 Fr) to facilitate blood clot expulsion. Coude catheters have a curved tip designed to ease passage through the prostatic urethra.

Up to 50% of hospitalized patients receive indwelling catheters during their stay. The prevalence of Foley catheter use in longterm care facilities ranges from 7.5% to10%. Many of these catheters are unwarranted, placed for inappropriate indications such as urinary incontinence (in the absence of an attempt at conservative therapy) or nursing/patient preference. The next section will review appropriate indications for indwelling catheter placement, as well as acceptable alternatives and strategies to avoid or reduce the duration of catheterization.

II. Identify the Goal Behavior.

Absolute indications for catheterization:

  • Acute urinary retention (functional or anatomic)

  • Monitoring urine output in critically ill patients (i.e. sepsis, severe hemorrhage, decompensated heart failure)

  • Management of gross hematuria with clots

  • Intraoperative assessment of fluid status during major surgery

  • Perioperative management of urine outflow in certain genitorurinary or adjacent structure surgeries (i.e. gynecologic or colorectral)

  • Management of perineal or sacral wounds in patients with incontinence

  • Pharmacologic infusions (i.e. BCG in bladder cancer)

  • Chronic neurogenic bladder

  • Patient comfort at end of life

Relative indications for catheterization:

  • Obtaining a urine sample in a patient who cannot reliably provide a "clean catch"

  • Management of urinary incontinence after failure of alternative therapies

Absolute contraindication for catheterization (urologic consultation mandatory):

  • Documented or suspected acute traumatic urethral injury

Relative contraindications for catheterization (urologic consultation strongly advised):

  • Urethral stricture

  • Artificial urethral sphincter

  • Recent surgery of urethra or bladder


The two most important strategies for avoiding complications from urinary catheters are avoiding unnecessary catheterization and removing indwelling catheters when no longer needed. Indications for continued catheterization should be evaluated on a daily basis. The use of specific Foley catheter protocols, daily checklists, automatic stop orders, and multidisciplinary rounds have all been shown to reduce urinary catheter utilization and catheter associated urinary tract infections. Whenever possible, alternatives to internal catheterization should be considered.

Alternatives to Foley catheters:

  • External catheter systems. Available as penile sheath catheters (i.e. condom catheters) for men or urinary pouches for women (and men with a small or retracted penis). Advantages include reduced incidence of urinary tract infection, improved comfort, and minimization of mechanical complications associated with indwelling catheter placement (see below). Disadvantages include penile injury through ulceration, scarring, and tissue ischemia. Patients with penile skin sensory loss must be monitored closely and are at higher risk for serious complications. Urine output cannot be reliably measured (due to leakage), and external catheters have no role in relieving urinary retention.

  • Intermittent catheterization. The bladder is decompressed with recatheterization on a regular basis (i.e. every 6 hours). It avoids complications associated with chronic indwelling catheters and has been shown to reduce the incidence of catheter associated urinary tract infections. Strict sterility is not thought to be crucial, and randomized trials comparing clean intermittent catheterization (where soap and water are used to clean the urethral meatus prior to catheterization) with sterile techniques have not shown a difference in infection rates. Single use catheters have no clear advantage over multiple use systems.

III. Describe a Step-by-Step approach/method to this problem.

Technique for transurethral Foley catheter placement

Patient is placed in the supine position (frog leg position for women). Catheter balloon should be inflated to check for defects, then deflated for insertion. Periurethral region is cleaned with antiseptic system (usually provided with catheter kit). Sterile gloves are worn (sterile gown, mask, and cap are not required). Sterile lubricant is applied to the catheter tip (lidocaine based lubricants can be used and may reduce patient discomfort). Sterile drapes are placed around urethral meatus.

For men, the penis is grasped firmly with the non-dominant hand and held perpendicular to patient (i.e. towards the ceiling). In women, the non-dominant hand spreads the labial folds for improved urethral meatus exposure. The catheter is then advanced slowly into the urethra (when using Coude catheters, the curved tip should point caudally). The external sphincter may provide some resistance in men. The catheter should be advanced to the hub. The balloon is inflated only after urine is seen. Once inflated, the catheter is withdrawn until slight resistance is felt. Drainage tubing should be anchored to the leg to prevent excessive catheter traction.

If urine is not obtained, suprapubic pressure may initiate flow. In women, check for vaginal catheterization. Gentle irrigation using 10 to 20 ml of sterile saline may return urine mixed with saline, suggesting appropriate placement. Consider urologic consultation if unable to obtain urine, or if urethral injury is suspected.

Catheter care:

  • Cleanse with soap and water around catheter. There is no known advantage to using antimicrobial agents.

  • If leakage occurs, catheter can be replaced with larger version (i.e. upgrade 14 Fr catheter to 16 or 18 Fr)

  • Empty collection bag regularly

  • Do not routinely replace catheter, as long as urinary flow is adequate

  • No known role for antimicrobial irrigation

  • Catheter may be irrigated with sterile saline if draining poorly

  • Keep drainage bag below level of bladder

IV. Common Pitfalls.


The most common complications of Foley catheters include mechanical trauma, bleeding, and infection. Less common complications include catheter blockage and urinary outflow obstruction. The catheter can erode through the bladder wall and cause perforation and/or fistula. It can become entrapped, occasionally requiring surgical intervention. Spontaneous rupture of the urinary catheter balloon can occur, and any catheter that "falls out" should be examined for balloon integrity (cystoscopy should be performed if balloon fragments cannot be located). Bladder stone formation can also occur.

Urethral trauma should be suspected in the presence of bleeding and pain following attempted catheter insertion. Potential sequelae include creation of a false passage, infection, urethrocutaneous fistula, and urethral stricture. Urethral inflammation may lead to urinary retention post-catheter discontinuation. Urinary incontinence following catheterization is also common, and usually temporary.

The balloon may fail to deflate due to a faulty valve or crystal formation in balloon channel. The first step is to cut the balloon valve from the catheter. If water does not drain, urology consultation is mandatory.


Twenty percent of hospital acquired bacteremias originate from infected urinary catheters, resulting in significant morbidity, mortality and costs. Rates of catheter colonization are up to 10% per catheter day, and almost all indwelling catheter systems will be colonized within a few weeks of placement. Catheter associated urinary tract infection can occur up to 48 hours after catheter removal, and bacteria tend to have greater antibiotic resistance than typical ambulatory uropathogens. Risk factors for infection (other than each additional day of urinary catheterization) include diabetes mellitus, female sex, substandard catheter placement and care, and bacteruria.

If an infection is suspected, the indwelling catheter should be removed prior to obtaining a urine sample. Culturing urine from the drainage bag should be avoided, as results may represent colonization rather than an active pathogen. If unable to obtain a mid-stream urine sample, the bladder can be recatheterized. There is no known role for prophylactic antibiotics in preventing infection.

Routine cultures are not warranted for patients with indwelling catheters.

V. National Standards, Core Indicators and Quality Measures.

Surgical Care Improvement Project (SCIP):

Foley catheters must be removed by midnight of post-operative day 2. Exceptions are made for urologic, gynecologic, or perineal surgery. Physicians must document reason for leaving catheter in beyond allowable time period.

VI. What's the evidence?

Niël-Weise, BS, van den Broek, PJ. "Urinary catheter policies for short-term bladder drainage in adults". Cochrane Database Syst Rev.

Cravens, D, Zweig, S. "Urinary catheter management". Am Fam Physician. vol. 61. 2000. pp. 369-376.

Johnson, JR, Kuskowski, MA, Wilt, TJ. "Systematic review: antimicrobial urinary catheters to prevent catheter-associated urinary tract infection in hospitalized patients". Ann Intern Med. vol. 114. 2006. pp. 116-126.

Meddings, J, Rogers, MA, Macy, M, Saint, S. "Systematic review and meta-analysis: reminder systems to reduce catheter-associated urinary tract infections and urinary catheter use in hospitalized patients". Clin Infect Dis. vol. 51. 2010. pp. 550-560.

Igawa, Y, Wyndaele, JJ, Nishizawa, O. "Catheterization: possible complications and their prevention and treatment". Int J Urol. vol. 15. 2008. pp. 481-485.

Daneshmand, S, Youssefzadeh, D, Skinner, EC. "Review of techniques to remove a Foley catheter when the balloon does not deflate". Urology. vol. 59. 2002. pp. 127-129.

Holroyd-Leduc, JM, Sands, LP, Counsell, SR, Palmer, RM, Kresevic, DM, Landerfeld, S. "Risk factors for indwelling urinary catheterization among older hospitalized patients without a specific medical indication for catheterization". J Patient Saf. vol. 1. 2005. pp. 201-207.

Schumm, K, Lam, TBL. "Types of urethral catheters for management of short-term voiding problems in hospitalised adults". Cochrane Database Syst Rev.

Hooton, TM, Bradley, SF, Cardenas, DD, Colgan, R, Geerlings, SE, Rice, JC. "Diagnosis, prevention, and treatment of catheter-associated urinary tract infection in adults: 2009 international clinical practice guidelines from Infectious Disease Society of America". Clin Infect Dis. vol. 50. 2009. pp. 625-663.

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