Indwelling Catheter Management: From Habit-based to Evidence-based Practice

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     Indwelling urinary catheters are used in the care of more than five million patients per year. Prevalence rates range from 4% in home care to 25% in acute care. Catheter-associated urinary tract infections account for more than 40% of all nosocomial infections and can be associated with significant complications. Clinical practices in catheter management vary widely and frequently are not evidence-based. Effective nursing measures include: identifying patients who no longer need indwelling catheters, discussing appropriate catheter alternatives, and providing patient and caregiver education. Many catheter-associated problems can be avoided by selecting a closed catheter system with a small size catheter (14 to 18 French with a 5-cc balloon), following manufacturer’s recommendations for inflation/deflation, maintaining a closed system, securing the catheter, and properly positioning the drainage bag. Practices such as routine catheter irrigation should be avoided. Current recommendations related to the management of encrustation and blockage also are discussed. Providing evidence-based catheter management strategies may reduce the rate of catheter-associated urinary tract infection, catheter encrustation, and leakage as well as the discomfort and costs associated with these complications.

     Over the past 65 years, the indwelling urinary catheter has become one of the most commonly used medical devices in hospitals, long-term care facilities, and the home. Although nurses routinely manage patients with indwelling catheters, studies indicate that clinical practices vary widely and frequently are not evidence-based.1,2 Caregivers and patients sometimes fail to realize that catheters can be associated with significant complications and that preventive care is critical. The goal [2]throughout healthcare today is evidence-based practice, and all nursing interventions should be guided by this principle. This article provides a review of current knowledge and recommendations regarding indwelling catheter management.

Indications for Use

     Approximately five million patients are treated with indwelling catheters per year.3 Prevalence rates range from 4% in home care4 to 25% in acute care.5 Short-term catheter use (ie, <30 days) is indicated for a variety of reasons, including management of acute retention, intra- and postoperative bladder decompression, and monitoring urinary output.3,6 Short-term catheter use is usually well tolerated, although urinary tract infection is a significant issue. In contrast, long-term catheter use (>30 days) can be associated with multiple complications including infection, bladder spasms, urethral erosion, hematuria, stones, epididymitis, urethritis, periurethral abscess, unprescribed removal, pain, fistula formation, obstruction secondary to encrustation, and leakage.7 For this reason, long-term indwelling urinary catheters should be used only for patients who cannot satisfactorily be managed with less invasive options. Specific indications for long-term catheter use include retention management in patients who are not candidates for intermittent catheterization, Stage III or Stage IV pressure ulcers on the trunk, and palliative or terminal care.6-8 Patients with indwelling catheters should be periodically assessed to determine the potential for catheter removal.

Types of Catheters:

Suprapubic versus Urethral

     Long-term catheters may be placed into the bladder via the urethra or a suprapubic incision. Although suprapubic catheters are thought to have advantages such as lower infection rates, increased patient acceptance, and ease of self-care, they are not without problems.6 Suprapubic catheters are contraindicated in patients with intrinsic sphincter deficiency or chronic unstable bladders.7 Complications such as urinary tract infection, leakage from the urethra or stoma, bladder spasms,9 and difficult catheter removal10 all have been reported. European studies indicate that patients with suprapubic catheters have lower rates of urinary tract infection; however, they have a significant increase in bladder stone formation.11,12 In the US, scant research has produced few clinical articles regarding the use, indications, and complications of suprapubic catheterization.

     An important aspect of management of the patient with a suprapubic catheter is catheter securement. Unsecured catheters lead to enlargement of the stoma tract, leakage, and the need for larger diameter catheters. Difficult removal with trauma and bleeding from the stoma tract can occur from balloon cuffing on deflation, especially with silicone catheters.13

Catheter Materials

     Urinary catheters are available in latex and silicone. Hydrogel, silicone elastomer, and antimicrobials are common catheter coatings, designed to provide a smooth surface that protects against irritation of the urethral mucosa and encrustation. Each coating varies somewhat in its performance and benefits. Quality catheters have coatings applied to inner and outer surfaces.

     Latex. Latex catheters are soft, flexible, conformable, and low cost — they continue to be one of the best catheter choices available.6 Red rubber latex catheters have the added benefit of being radiopaque; the addition of barium to the latex also makes these catheters firmer and less likely to kink. Due to the rise in latex sensitivity, some facilities are removing all latex products and going “latex free.”
     Although latex sensitivity can be an issue for some patients, the actual prevalence of latex allergy in the general public is low (around 1%).14 Latex sensitivity most commonly occurs in medical personnel, rubber industry workers, or patients with repeated exposure, such as children with spina bifida.15 In addition, individuals with a history of atopy or allergies to bananas, avocado, kiwi, or chestnuts may cross-react to latex15; therefore, taking a thorough history to identify latex-sensitive patients is important. Strict latex precautions, including use of latex-free catheter kits and drainage systems, should be followed with latex-sensitive patients. Since 1998, the Food and Drug Administration (FDA) has required that medical devices containing latex be identified by including a latex warning statement on the product label.16 Nurses should check labeling before selecting a catheter for patients with known latex sensitivity.

     Silicone. Silicone catheters are available uncoated or hydrogel-coated. Studies have shown that silicone is more biocompatible with urethral tissue than latex, leading to reduced incidence of urethritis and possibly of urethral strictures.17 However, animal studies of catheters used for more than 6 weeks showed no difference between silicone and latex catheters in terms of inflammatory changes.17 Some catheter manufacturers use a leaching process to remove latex proteins and processing chemicals that could lead to reactions. One advantage of silicone catheters is that the thinner walls provide larger internal lumens per external diameter and are less prone to collapse during aspiration.18 This feature results in greater flow and is advantageous for patients with blood clots or sediment in their urine. A disadvantage of silicone catheters is the permeability of the balloons, resulting in loss of fluid over time18; silicone balloons should be checked regularly, adding fluid as needed. Another disadvantage of silicone catheters is the tendency of the balloons to form creases or cuffs when deflated, which can lead to painful and difficult removal.10,13 Finally, patients may complain that silicone catheters are firmer and cause more discomfort than softer latex catheters.

     Silicone-elastomer. Silicone-elastomer coated catheters are sometimes confused with 100% silicone catheters; these catheters are actually latex catheters coated inside and out with silicone. The difference between silicone-coated and 100% silicone catheters is worth noting for two reasons: 1) patients who are latex-sensitive should be managed with all-silicone catheters, not silicone-coated catheters, and 2) patients who are not latex-sensitive may prefer silicone-coated catheters to all-silicone catheters because these catheters combine the strength and flexibility of latex with the durability and reduced encrustation typical of all-silicone catheters.

     Hydrogel coating. Hydrogel-coated catheters (eg, Lubricath®, C.R.Bard, Inc. Covington., Ga.) are soft and highly biocompatible. Because they are hydrophilic, they absorb fluid to form a soft cushion around the catheter; thus, reducing friction and urethral irritations.

     Antimicrobial coatings. The newest technology involves the use of antimicrobial coatings designed to reduce bacterial attachment, colonization, and migration with the goal of preventing catheter-associated urinary tract infection (CAUTI) and nosocomial urinary tract infections (NUTI). One type of coating combines a thin layer of silver alloy with hydrogel (Bardex® IC, C.R. Bard, Inc. Covington, Ga.). Multiple studies have shown this coating to be effective in reducing CAUTI without causing bacterial resistance.3,19 A randomized double blind study of 850 catheterized patients demonstrated that use of these catheters for up to 20 days provided a 30% reduction in CAUTI.3 Numerous randomized studies support the effectiveness of these catheters against NUTI3,19; as yet, these catheters have not been studied in patients with long-term indwelling catheters to determine efficacy and cost effectiveness. Silver-hydrogel coated catheters are available in latex and silicone.

     A catheter coated with nitrofurazone is also available. Studies have shown that this catheter (Release-NF, Rochester Medical, Stewartville, MN) can reduce UTI rates for up to 7 days; however, they failed to provide a significant reduction in infections caused by organisms resistant to nitrofurazone, and clinicians are concerned that this coating could lead to selective antimicrobial resistance.3

Catheter Size

     The prevailing guideline for catheter size is to use the smallest diameter that will provide good drainage, typically a 14 to 18 French unless the patient has blood clots or sediment that occlude the lumen. Larger catheters are uncomfortable for the patient, can lead to urethral erosion, and impair paraurethral gland function. The paraurethral glands produce mucous that protects against ascending bacteria; compression of these glands can result in urethritis or ascending infection.20 Nurses commonly ask about management of a patient who already has a large catheter (>18 French) in place. In this case, the catheter should be downsized with each catheter change until the catheter is in an acceptable size range.

Straight-tipped versus Coude-tipped Catheters

     For routine catheterization, a straight-tipped catheter should be used. Coude-tipped catheters have a firm, curved tip designed to negotiate the male prostatic curve and may be helpful for difficult insertions. Coude-tipped catheters should be inserted with the tip pointed upward towards the patient’s umbilicus.

Catheter Balloons

     Confusion exists among nurses regarding selecting and filling catheter balloons for routine catheterization; many use 5-cc and 30-cc balloons interchangeably. Either a 1.5-cc or 3-cc (pediatric) or 5-cc (adult) balloon should be used for routine catheterization, filled per manufacturer directions. Catheter balloons are designed to secure the catheter in the bladder, not occlude the urethra or prevent leakage. When filled, the 30-cc balloon weighs approximately 48.2 g and sits high in the bladder.20 The added pressure on the bladder neck and pelvic floor can lead to bladder spasms and leakage. Over time, this can damage the bladder neck, resulting in inability to retain a catheter. In addition, the large balloon results in stasis because the drainage eyes sit above the balloon and, therefore, above the urine.21

     Patients with long-term catheters are at significant risk for bladder stones that can puncture the retention balloon. Any patient who experiences repetitive, spontaneous balloon deflation should be evaluated by the urologist for the presence of bladder calculi.

Guidelines for Insertion

Guidelines for catheter insertion are outlined in Table 1.
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Handwashing

     Handwashing is considered the single most important action to prevent infections.22 Patients and caregivers alike should be taught to wash their hands with antibacterial soap or alcohol-based hand cleaners before and after catheter insertion, changing drainage systems, or manipulating the catheter.

Male Catheterization

     Male catheterization can be particularly difficult due to the greater urethral length and the prostatic curve. Copious lubrication is essential. Injecting 10 cc of water-soluble lubricant directly into the urethra distends the urethra and places the lubricant high in the urethra where it is needed.23 Using lidocaine jelly 2% reduces discomfort and can prevent urethral spasm; catheter insertion should be delayed for 2 to 5 minutes in order for the anesthetic to take effect.24 The catheter should be advanced almost to the bifurcation to avoid inflation of the balloon in the urethra. Placement should be confirmed by urine return before the balloon is inflated. Lubricating jelly in the drainage eyes may delay urine return; gentle aspiration of urine can confirm placement.

Female Catheterization

     Identification of the female urethra may be difficult, as landmarks vary with each woman. In older women, the urethra may prolapse into the upper vaginal wall. The catheter should be inserted with the patient in the supine position. Insertion of a catheter from the rear, as recommended in nursing procedure manuals, may introduce fecal bacteria into the bladder and should be avoided unless the patient has limited mobility or restricted range of motion, preventing a supine position. In female patients, it is important to identify the urethra before beginning the sterile procedure. If the catheter is inadvertently placed into the vagina, it should be left temporarily as a landmark and a new catheter obtained for insertion into the bladder. Good lighting is essential, and an assistant may be needed to maintain sterile technique, especially with elderly or combative patients.

Balloon Pretesting

     Pretesting catheter balloons is commonly recommended as a way to prevent insertion of a defective catheter. Some catheter manufacturers no longer recommend pretesting because their balloons are pretested during the manufacturing process. Pretesting silicone balloons is not recommended; the silicone can form a cuff or crease at the balloon area that can cause trauma to the urethra during catheter insertion.10,13

Inflation

     Much confusion exists about the proper volume to be used for balloon inflation. The guiding principle is to follow the manufacturer’s instructions. Catheter manufacturers test their balloons to determine the amount of fluid required to obtain a symmetrical balloon. Under- or overinflation can result in an asymmetrical balloon, which can deflect the catheter tip to one side. This deflection can cause occlusion of the drainage eyes, irritate the bladder wall, and lead to bladder spasms (see Figure 1 and Figure 2). In general, a 5-cc balloon requires about 10 cc of fluid for symmetrical inflation. Manufacturers recommend that sterile water be used to fill catheter balloons; normal saline can lead to crystal formation in the inflation lumen (and difficulty deflating the balloon), and inflation with air will cause the balloon to float in the [4]bladder.24 Silicone catheter balloons can lose fluid over time as fluid diffuses out into the urine; therefore, fluid levels should be checked at least every 2 weeks and fluid added as needed.25

Catheter Securement

     All urinary catheters should be secured, yet securement is not routinely performed in practice. Unsecured urinary catheters can lead to bleeding, trauma, pressure sores around the meatus, and bladder spasms from pressure and traction.26 It is recommended that the catheter be secured to the thigh for women and to the upper thigh or lower abdomen for men. The lower abdominal position in men decreases the potential for pressure necrosis and urethral erosion at the penile-scrotal junction.24 Ambulatory men may find abdominal securement difficult; these patients can be instructed to secure the catheter to the upper thigh in the daytime and to change the position to the lower abdomen for sleep.

     Many securement devices are available, including adhesive, non-adhesive straps and catheter-specific anchors. A new catheter specific anchor (StatLock Foley™, Venetec International®, Inc. San Deigo, Calif. ) offers advantages that include a reclosable locking mechanism that swivels as the patient moves and an adhesive comfort pad that can be left in place for up to 1 week without altering skin integrity.26 Whatever product is selected, nurses should instruct patients in the proper use and removal of the securement device.

Urine Collection

     Drainage bags now come with a special “safe sampling” port designed to obtain urine specimens while maintaining a closed system. The CDC recommends that urine specimens be obtained directly through these ports using an aseptic technique.8 The drainage tubing is occluded below the port temporarily, allowing the urine to collect in the tubing. The port is swabbed with alcohol, and the urine is withdrawn following manufacturer’s instructions using a needle, blunt cannula, or luer lock syringe. Urine for a culture and sensitivity should be obtained from a newly inserted catheter and drainage bag to avoid culturing the system (catheter and drainage bag) rather than the urine.

Catheter Irrigation

     Catheter irrigation is not recommended unless obstruction with clots or mucous is anticipated8; breaking the catheter drainage bag connection (closed system) is a major point of bacterial entry into the system.3 Closed, continuous irrigation with a three-way catheter may be necessary for patients with repeated obstructions.8 The CDC recommends that catheter irrigations conform to aseptic technique with sterile saline and sterile syringe for each irrigation, but home care agencies may have a policy for cleaning and reuse of irrigation supplies. Vigorous irrigation and aspiration can be damaging to delicate bladder mucosa and should be avoided.27

Catheter Change Interval

     No evidence exists to support routine monthly catheter changes. Rather, nurses should monitor patients closely for signs of blockage or encrustation and should change the catheter based on specific patient needs.7,8

Catheter Removal

     Traditionally, nurses have been taught to aspirate fluid from catheter balloons for removal of fluid. Recent studies have demonstrated that aspiration by pulling on the syringe plunger may result in collapse of the inflation lumen; encourage formation of creases, ridges, or cuffing at the balloon area; and increase the catheter balloon diameter size on deflation.10,13 This enlargement of the balloon area can result in difficult removal and urethral trauma. One major catheter manufacturer is now recommending that the fluid be allowed to return to the syringe by gravity and not by aspiration. (CountItDown, C.R. Bard, Covington, Ga.) Due to the small diameter of the inflation lumen, it may take up to 30 seconds for all of the fluid to return (see Table 2). Manufacturer’s instructions for deflation should be followed. [5]

Cleaning and Reuse

     Over the past few years, technique has shifted from sterile to clean in the home care setting. Cleaning and reusing catheter drainage bags and irrigation supplies are now common. Manufacturers do not recommend cleaning and reuse of products labeled “single use sterile” because these products have not been tested to see how various cleaning products may effect them. Cleaning medical products can be an added burden to patients or caregivers who may be confused regarding cleaning procedures. Cleaning procedures must be individualized and take patient and caregiver needs and their ability to follow the procedure into consideration.4 Recommended solutions for cleaning urine drainage bags or irrigation equipment include full strength vinegar, one part vinegar to three parts water (1:3),22 and 4 oz of bleach (5.25%) to 1 gallon of water.

     Vinegar has been used safely in the home for many years — it decrystalizes sediment that may build up and changes the pH balance, which inhibits bacterial growth.25 Bleach solutions have been found to have excellent antimicrobial activity but lose strength quickly; hence, they must be mixed daily.4,28,29 If bleach is used, patients must be taught proper handling, which includes avoiding inhalation and contact with the skin, eyes, and clothing. Solutions should be instilled down the tubing and into bag. Care should be taken to avoid wetting the air vent located on the top of the drainage bag; a wet vent can lead to impaired drainage due to air lock. After cleaning, the product should be rinsed thoroughly and air should be instilled into the bag to promote drying. After drying, items should be stored in a covered container.

Routes of Infection

     Studies indicate that bacteria enter the bladder by three routes: the catheter-meatal junction, catheter-drainage tubing connection, and the drainage bag outlet device3 (see Figure 3). Current prevention and management strategies focus on these [6]three routes of entry.

     Catheter-meatal junction. Bacteria enter the bladder from periurethral contamination at time of catheter insertion or later due to capillary action.3 Periurethral bacterial colonization has been found to be an important risk factor in both men and women; however, extra-luminal migration at the catheter-meatal junction is thought to occur more frequently in women, due to their short urethra.3,30 Nursing procedure manuals recommend washing the perineal area thoroughly with soap and water before the sterile catheterization procedure begins; in practice this is not routinely done unless the patient has fecal incontinence. This important step should not be omitted.

     Insertion of an indwelling catheter is a sterile procedure and strict aseptic technique should be followed. Either a 10% povidone iodine or 1% to 2% aqueous chlorhexidine solution can be used to clean the meatus and surrounding area.8 Although routine perineal care is recommended, catheter manipulation should be avoided because it is thought to contribute to bacterial migration into the bladder around the catheter-meatal junction.8 At one time, scheduled meatal care was considered to be effective and necessary after catheter insertion; however, studies have not demonstrated that meatal care with soap, water, povidone iodine, or antibacterial ointments or creams decreases the incidence of CAUTI.8 Petrolatum-based creams or ointments can degrade latex catheters and should be avoided.

     Catheter drainage bag tubing connection. Maintaining a closed drainage system has been found to be key in preventing CAUTI.3 Studies have shown that bacteriuria occurs within 4 days when open systems are used compared to 30 days when a closed system is used.3,31 Nurses should select catheter kits that have the catheter preconnected and sealed at the catheter-drainage bag junction.

     Closed system maintenance can be difficult for home care patients who frequently switch from standard drainage bags at night to leg bags during the day. These frequent breaks in the system greatly increase the risk of CAUTI. Currently, no leg bag systems have been designed to hold the urine volume produced during sleep. However, nurses can attach a sterile leg bag to the catheter at the time of insertion and use extension tubing to attach the standard drainage bag to the leg bag at bedtime. The standard drainage bag is removed and cleaned each morning. In light of the importance of maintaining a closed system, further product development is needed in this area.

     Drainage bag outlet device. Studies have shown that retrograde bacterial migration from the urine drainage bag outlet tube to be a major source of bacterial contamination.3 A study by Maki et al32 found that allowing the drainage tubing to drop lower than the drainage bag was associated with a significant increased risk of CAUTI. Infection control drainage bags with microbicidal outlet tubes and complete bacteriostatic urine collection systems with microbicidals compounded throughout the drainage bag are now available.

     Drainage bags are designed with either an anti-reflux valve or anti-reflux chamber to prevent reflux of contaminated urine from the bag into the tubing. Drainage bags should be positioned below the level of the patient’s bladder. Drainage bags should be hung on the end of the bed with the tubing in a straight line, avoiding looping or kinking to promote unobstructed urine flow.8 Transporting patients with drainage bags positioned on the patients abdomens or between their legs should be avoided. Stainless steel drainage bag holders are available from medical supply companies, or the patient can be taught to use a new plastic trashcan or tub to hang the bag properly.

     Patients and caregivers should receive instructions regarding the following points:
     • Keep drainage bags off the floor below the level of the bladder
     • Do not allow the outlet tube to touch the collection container or floor when emptying
     • Disinfect the urine collection containers after use
     • Empty the drainage bag when 1/2 to 2/3 full to avoid traction on the catheter from the weight of the drainage bag.

     Nurses should be aware that patients might have strong preferences regarding the type of outlet device that works best for them. Patients with disabilities or limited mobility may require a special type of outlet device.

Common Catheter-associated Complications

     Catheter-associated UTI. Much of the recent research on indwelling catheters has focused on the role of biofilms in the development of CAUTI, NUTI, antibiotic resistance, and catheter encrustation leading to blockage. With an understanding of biofilms, nurses can better understand how CAUTIs and catheter encrustations develop.

     Biofilms develop on urinary catheters when bacteria adhere to and multiply on catheter surfaces, forming mushroom-like colonies protected in a polysaccharide matrix.33 Once these bacteria attach, they multiply quickly, swarm over the inner-luminal and extra-luminal surfaces of the catheter, and advance in a retrograde fashion.3 Bacteria frequently come from the hands of healthcare workers, cross contamination from other patients, or from the patient’s own colonic or perineal flora.19 Biofilms are of particular concern in the medical community because they can develop on any indwelling device, including intravenous catheters, needleless connectors, endotracheal tubes, pacemakers, mechanical heart valves, and urinary catheters, and they are highly resistant to traditional antimicrobial treatment.34 The longer a urinary catheter is left in place, the higher the risk of biofilm formation leading to infection. For this reason, urinary catheters should be removed as soon as possible.3,8 Studies have shown that all traditional catheter materials are subject to biofilm development.35

     Risk factors for CAUTI. Risk factors for catheter-related infection include prolonged catheterization (>6 days), female gender, inserting the catheter outside the operating room, diabetes, malnutrition, renal insufficiency, monitoring of urine output, and positioning the drainage tubing below the drainage bag outlet.3 Other contributing factors are contamination during insertion, fecal incontinence (contamination by Escherichia coli in women), and interruption of the closed-catheter system.3 The most important, potentially modifiable, risk factor is prolonged catheterization (>6 days) — by day 30 of catheterization, essentially all patients are infected.3

     Identification and treatment of CAUTI. Catheter-associated urinary tract infection is the most frequently reported complication of urinary catheterization. More than 40% of all nosocomial infections are catheter-associated.3 More than 1 million patients per year in hospitals and extended care facilities will acquire a CAUTI, and studies suggest that CAUTIs are associated with substantially increased death rates.3 Although not all CAUTIs can be prevented, it is believed that a large number could be prevented by proper catheter management.8 The CDC guideline (see Table 3) addresses prevention of CAUTI for the care of patients with short-term urinary catheters; however, patients with chronic indwelling catheters may have different needs.8 Catheter-associated urinary tract infections have been identified as a leading source of [7]nosocomial antibiotic- resistant pathogens,3 and silver alloy-hydrogel catheters are recommended to reduce infection rates and cost.3,19

     Diagnosis of urinary tract infection can be difficult in a patient with a long-term indwelling catheter, especially because patients may be asymptomatic.36 Specific guidelines for initiation of treatment for UTI in catheterized patients are outlined in Table 4.37,38 Because bacteriuria is present in all patients with indwelling catheters, colony counts are used to distinguish between colonization and actual clinical infections. Urine cultures obtained from the drainage bag safe-sampling [8]port that show colony counts of >102-3 cfu/mL are considered to be indicative of a true CAUTI.3

     Changing the catheter when antibiotics are started is important, as studies show this intervention hastens clinical improvement, reduces febrile days, and decreases the rate of relapse.37

     Catheter leakage. No other catheter management issue causes more unnecessary catheter changes than leakage or bypassing. Catheter leakage is thought to affect as many as 25% to 65% of patients with indwelling catheters.39 Long-term indwelling catheters can lead to small non-compliant bladders, and leaking can occur with small amounts of urine in the bladder. Causes of leakage include bladder spasms, infection, fecal impaction or constipation, luminal occlusion, catheter encrustation, and loss of elasticity of the urethra (female).39-41

     The nurse must focus first on identifying the cause of the leakage; interventions then can be tailored to the cause of the problem. Changing the catheter is indicated if the lumen is occluded, but practices such as adding fluid to a catheter balloon or increasing the catheter or balloon size can lead to increased spasm and leakage and are contraindicated (see Table 5).

     Bladder spasms are involuntary contractions of the bladder and are common in patients with urinary catheters, spinal cord injuries, or diseases that lead to neurological deficits.39 Bladder spasms can be strong enough to push the catheter out of the urethra with the balloon inflated. Antispasmodic drugs such as oxybutynin and flavoxate can be effective at treating bladder spasms, but may have undesirable central anticholinergic effects.6 Known bladder irritants such as caffeine and alcohol should be [10]avoided in patients with known bladder spasms, as well as large-sized catheters and balloons that may add pressure on the sensitive trigone area. Symmetrical balloon inflation, catheter securement, and adequate fluid intake all help reduce the risk for bladder spasms and resultant leakage. Several studies have shown a direct correlation between increased bladder spasms, leakage, and infection.40

     Stool in the rectal vault or colon can occlude the catheter lumen or increase pressure in the bladder, leading to bladder spasm and leakage. In a study by Ziemann et al,39 81% of all patients with leakage had constipation or fecal impaction. This finding underscores the importance of bowel management programs designed to eliminate or promptly correct constipation.

     Over time, large-sized catheters stretch the urethra. Urethral dilation should be suspected in a patient with a long-term catheter who has a history of large catheters or large balloons and who has persistent leakage with no apparent cause. These patients should be referred to a urologist and evaluated for other management options.

     Blood clots, sediment, mucus, and crystal precipitate are commonly seen in catheterized patients and can lead to occlusion of the drainage eyes or catheter lumen. Irrigation with normal saline can remove clots or debris, but saline is ineffective at removing occlusions caused by catheter encrustations.27 If sediment or blood clots are causing frequent occlusion, a larger catheter and catheter irrigations may be necessary.

     Catheter encrustation. Catheter encrustation occurs in up to 50% of long-term catheterized patients and can lead to emergency room visits and frequent catheter changes.27 Encrustation is caused by infection of the urinary tract by Proteus mirabilis or other urease-producing bacteria. The activity of the urease raises the urinary pH (>7), causing precipitation of calcium and magnesium phosphates that attach to biofilm on the catheter inner and outer surfaces.33 Studies have shown that antibiotics or antiseptic solutions are ineffective at eradicating biofilms.42 Patients are classified as either “blockers”(patients who consistently and repeatedly develop encrustations, resulting in decrease urine flow) or “non-blockers.”27,35 Acidifying the urine with cranberry juice or pills or vitamin C has not been shown to delay or decrease encrustation and blockage; however, a recent study found that increasing fluids decreased time until blockage.43 In addition, studies have shown that acidic irrigant solutions instilled into the bladder can dissolve encrustations, although further studies are needed regarding optimal volume and frequency and the effects on bladder mucosa.27 In patients with frequent blockage due to encrustations, a prescription citric acid bladder irrigant solution (Renacidin®, Guardian Laboratories, Hauppauge, NY) may be instilled into the bladder to dissolve encrustation.

     Current recommendations or management of encrustation and blockage include the following:
     • Inspect and palpate the catheter for signs of encrustation
     • Schedule catheter changes based on blockage history (ie, usual time to blockage)
     • Increase fluid intake
     • Keep extra catheter kits available
     • Perform two sequential bladder washouts with <50 cc acidic bladder irrigant solution instilled by gravity no more than every other day.27

Conclusion

     In caring for patients with indwelling catheters, nurses should aim for consistent and standardized practices based on current research. Nursing measures should include identifying patients who no longer need indwelling catheters and providing suggestions for appropriate alternatives. Many catheter-associated problems can be avoided by selecting a small size catheter with a 5-cc balloon, following manufacturer’s recommendations for insertion/removal, maintaining a closed system, securing the catheter, and properly positioning drainage bags. Habit-based practices such as adding fluid to catheter balloons to control leakage using 5-cc and 30-cc ballooned catheters interchangeably and routine saline irrigations should be avoided. With current knowledge of how catheter encrustation, blockage, and leakage occur, nurses can develop a plan of care that will prevent emergency visits and long-term complications. It may not be possible to prevent CAUTI, but by maintaining a closed system and following CDC guidelines, these infections may be delayed or reduced. Teaching the patient and caregiver about the catheter can lead to better acceptance of the device and reduce complications.