“Foley” Catheter Articles

Present-day healthcare employs several types of invasive devices, including urinary catheters, to improve medical wellness, the clinical outcome of disease, and the quality of patient life. Among urinary catheters, the Foley catheter is most commonly used in patients for bladder drainage and collection of urine.

External bladder drainage with an indwelling transurethral catheter is standard during kidney transplant. Difficult Foley catheter placement is a frequent problem and one of the most common reasons for intraoperative urology consults.

PURPOSE:Foley catheters cause a variety of harms, including infection, pain and trauma. Although symptomatic urinary tract infection and asymptomatic bacteriuria are frequently discussed, genitourinary trauma receives comparatively little attention.

MATERIALS AND METHODS:A dedicated Foley catheter nurse prospectively reviewed the medical records of inpatients with a Foley catheter at the Minneapolis Veterans Affairs Medical Center from August 21, 2008 to December 31, 2009. Daily surveillance included Foley catheter related bacteriuria and trauma. Data were analyzed as the number of event days per 100 Foley catheter days.

RESULTS:During 6,513 surveyed Foley catheter days, urinalysis/urine culture was done on 407 (6.3%) days. This testing identified 116 possible urinary tract infection episodes (1.8% of Foley catheter days), of which only 21 (18%) involved clinical manifestations. However, the remaining 95 asymptomatic bacteriuria episodes accounted for 39 (70%) of 56 antimicrobial treated possible urinary tract infection episodes (for proportion of treated episodes with vs without symptomatic urinary tract infection manifestations, p = 0.005). Concurrently 100 instances of catheter associated genitourinary trauma (1.5% of Foley catheter days) were recorded, of which 32 (32%) led to interventions such as prolonged catheterization or cystoscopy. Trauma prompting an intervention accounted for as great a proportion of Foley catheter days (0.5%) as did symptomatic urinary tract infection (0.3%) (p = 0.17).

CONCLUSIONS: In this prospective surveillance project, intervention triggering Foley catheter related genitourinary trauma was as common as symptomatic urinary tract infection. Moreover, despite recent increased attention to the distinction between asymptomatic bacteriuria and symptomatic urinary tract infection in catheterized patients, asymptomatic bacteriuria accounted for significantly more antimicrobial treatment than did symptomatic urinary tract infection. Elimination of unnecessary Foley catheter use could prevent symptomatic urinary tract infection, unnecessary antimicrobial therapy for asymptomatic bacteriuria and Foley catheter related trauma.

Written by:
Leuck AM, Wright D, Ellingson L, Kraemer L, Kuskowski MA, Johnson JR. Are you the author?
VA Medical Center, University of Minnesota, Minneapolis, Minnesota, USA.

Reference: J Urol. 2012 May;187(5):1662-6. doi: 10.1016/j.juro.2011.12.113.

 http://jurology.com/article/S0022-5347(11)06062-9/abstract

Evaluation of a catheter design which protects its tip with the retaining balloon when inflated, and has eyeholes at the base of the balloon to improve drainage.

Preclinical tests included assessment of retaining balloon performance, and microbiological blockage.

What is an Indwelling Catheter?

An indwelling urinary catheter (IUC), generally referred to as a “Foley” catheter, is a closed sterile system with a catheter and retention balloon that is inserted either through the urethra or suprapubically to allow for bladder drainage. External collecting devices (e.g. drainage tubing and bag) are connected to the catheter for urine collection 

Indwelling urinary catheters are recommended only for short-term use, defined as less than 30 days (EAUN recommends no longer than 14 days.) The catheter is inserted for continuous drainage of the bladder for two common bladder dysfunction: urinary incontinence (UI) and urinary retention.

Urologic Catheters: Indwelling | Intermittent | External

Indwelling urinary catheters (IUCs) are semi-rigid, flexible tubes. They drain the bladder but block the urethra. IUCshave double lumens, or separate channels, running down it lengthwise. One of the lumen is open at both ends and allows for urine drainage by connection to a drainage bag.



The other lumen has a valve on the outside end and connects to a balloon at the tip; the balloon is inflated with sterile water when it lies inside the bladder, and allows for retention in the bladder.  These are known as two-way catheters.  

The name of the Foley catheter comes from the designer, Frederic Foley, a surgeon working in Boston, Massachusetts, in the 1930s. His original design was adopted by C. R. Bard, Inc. who manufactured the first prototypes and named them in honor of the surgeon.

Foley Catheter Sizes

Catheter sizes are colored-coded at the balloon inflation site for easy identification

The relative size of a Foley catheter is described using French units (Fr).  In general, urinary catheters range in size from 8Fr to 36Fr in diameter. 1 Fr is equivalent to 0.33 mm = .013" = 1/77" in diameter.  

The crosssectional diameter of a urinary catheter is equal to three times the diameter.

Since urethral mucosa contains elastic tissue which will close around the catheter once inserted, the catheter chosen should be the smallest catheter that will adequately drain urine.  

Size Considerations

• The routine use of large-size catheters diameters can cause more erosion of the bladder neck and urethral mucosa, can cause stricture formation, and do not allow adequate drainage of peri-urethral gland secretions, causing a buildup of secretions that may lead to irritation and infection. 
• Larger Fr sizes (e.g., 20-24 Fr) are most commonly used for drainage of blood clots.  
• The most commonly utilized indwelling transurethral and suprapubic catheters range from 14 to 16Fr in both adult females and males. 
• A 14 or 16 Fr is also the standard catheter in most commercially available IUC insertion kits or trays.
• In adolescents, catheter size 14 Fr is often used but for younger children, pediatric catheter sizes of 6-12 Fr are preferred.  

Shape and Design Variations

The distal end of most urinary catheters contains two ports (lumen or channel or dual lumen).  One is a funnel shaped drainage channel to allow efflux of urine once the catheter is placed and the other is the inflation/deflation channel for infusion of water into the retention balloon.  The infusion port for the balloon is usually labeled with the size of the balloon (5cc or 30 cc) and the size of the catheter.

 
Three-way catheters are available with a third channel to facilitate continuous bladder irrigation or for instillation of medication.  This catheter is primarily used following urological surgery or in case of bleeding from a bladder or prostate tumor and the bladder may need continuous or intermittent irrigation to clear blood clots or debris. 

The catheter should have a smooth surface with two drainage eyes at the tip that allow for urine drainage.

Drainage eyes are placed either laterally or opposed. Opposing drainage eyes generally facilitate better drainage.

Catheter products have changed significantly in their composition, texture, and durability since the 1990s.

The challenge is to produce a catheter that matches as closely as possible to the normal physiological and mechanical characteristics of the voiding system, specifically the urethra and bladder. Foley catheters come in several subtypes, which are described in the area designs. 

References

1. Jahn P, Beutner K, Langer G. Types of indwelling urinary catheters for long-term bladder drainage in adults. Cochrane Database of Systematic Reviews 2012, Issue 10. Art. No.: CD004997. DOI: 10.1002/14651858.CD004997.pub3.Newman DK, Cumbee RP, Rovner ES. Indwelling (transurethral and suprapubic) catheters. In: Newman DK, Rovner ES, Wein AJ, editors. Clinical Application of Urologic Catheters and Products.  Switzerland: Springer International Publishing;2018,  47-77.
2. Newman DK. Devices, products, catheters, and catheter-associated urinary tract infections. In: Newman DK, Wyman JF, Welch VW, editors. Core Curriculum for Urologic Nursing. 1^st ed. Pitman (NJ): Society of Urologic Nurses and Associates, Inc; 2017, 439-66.
3. Newman DK. The indwelling urinary catheter: Principles for best practice. JWOCN. 2007;34:655-61 DOI: 10.1097/01.WON.0000299816.82983.4a
4. Newman DK, & Wein AJ. Managing and Treating Urinary Incontinence, Second Edition.  Baltimore: Health Professions Press;2009a;445-458.

Bacteriuria is anticipated in long-term indwelling catheter (IDC) use, and urinary tract infections (UTIs) and related issues are common. Defence mechanisms against infection are undermined by the presence of a Foley catheter, and adjustments to design could influence UTI risk.

Endovascular infra-renal abdominal aortic aneurysm repair (EVAR) has proven to be an effective, less invasive alternative to open aortic aneurysm repair with decreased 30-day mortality. Historically, urinary drainage catheters were routinely placed preoperatively before EVAR in our institution.