In a new review, Anne P. Cameron, MD, and Glenn T. Werneburg, MD, both of the Department of Urology, University of Michigan, Ann Arbor, explore the evolution, optimal use, complication risks, and management strategies surrounding Foley catheters, offering timely guidance for clinicians across specialties.

Ubiquity and Risks of Foley Catheters

Globally, an estimated 100 million urinary catheters are used annually. In U.S. hospitals, roughly 20% of patients have a catheter at any given time. Despite their utility, Foley catheters carry significant risks, particularly catheter-associated urinary tract infections (CAUTIs), encrustation, bladder spasms, and mechanical injuries.

The review underscores that best practices in catheter selection, insertion, maintenance, and removal are essential to minimize harm. Avoiding unnecessary catheter use remains the single most effective strategy for preventing complications.

Indications and Misuse: Getting It Right

Appropriate indications for Foley catheterization include acute urinary retention, neurogenic bladder dysfunction, accurate urine output monitoring in critically ill patients, wound protection in urogenital or sacral areas, and select postoperative situations. Catheter use is also justified for comfort care in end-of-life scenarios or in patients requiring prolonged immobilization, such as unstable spinal or pelvic fractures.

Conversely, inappropriate use persists—such as catheterizing for incontinence management, convenience in toileting, or specimen collection when a clean-catch sample is feasible. Clinicians are urged to reassess catheter necessity frequently and to remove catheters as soon as they are no longer clinically needed.

Catheter Types, Sizing, and Materials

Choosing the right catheter requires consideration of size, tip geometry, and material. The French (Fr) scale remains the standard, with 1 Fr equal to 0.33 mm of diameter. A typical adult male would often require a 16F or 18F catheter, while females generally require a 14F or 16F size.

Tip geometry is critical: straight-tipped catheters suffice for most, but coudé-tipped catheters are recommended for males with known or suspected prostate enlargement to navigate the prostatic urethra more easily.

Latex catheters are widely preferred for long-term use due to patient-reported comfort but are contraindicated in individuals with latex allergies or spina bifida. Silicone catheters offer a latex-free alternative but may cause greater urethral irritation. Balloon size selection is equally important, with standard 10 mL balloons used in most cases and larger 30 mL balloons reserved for specialized scenarios like post-prostatectomy hemostasis.

Insertion and Removal: Techniques That Matter

Insertion must always be performed with strict sterile technique. Proper lubrication and patient positioning are vital to ease catheter advancement, especially in male patients where resistance at the external sphincter is common. The catheter should only be inflated after urine return is confirmed to avoid balloon inflation in the urethra—a critical pitfall.

During removal, full balloon deflation is mandatory. Kinked tubing preventing full deflation must be corrected; otherwise, specialist referral is warranted. If significant urethral bleeding occurs during insertion, clinicians should suspect false passage creation, necessitating urologic evaluation.

Special Challenges in Catheterization

Patients with difficult anatomy—such as those with strictures, obesity, or altered vaginal anatomy—may require special positioning (e.g., lithotomy) or adjuncts like coudé catheters. Visualization tools, including specula, can assist with identifying the female urethral meatus.

In patients with spinal cord injuries or altered cognition, catheter securement is paramount to prevent traumatic dislodgement and urethral injury.

Managing Long-Term Indwelling Catheters

Maintenance protocols emphasize:

• Regular perineal hygiene with soap and water

• Maintaining a closed drainage system

• Keeping the drainage bag dependent below bladder level

• Switching between day and night bags properly disinfected

• Timely emptying of collection bags when half-full

Routine catheter change every 4 weeks is common practice, although no universal consensus exists.

"Management of incontinence in hospitalized men can be performed with a condom catheter, a body-worn urinal attached to the penis collecting urine without instrumenting the urinary tract," noted Dr. Cameron and Dr. Werneburg.

Complications: Prevention and Management

Catheter-Associated Urinary Tract Infections (CAUTIs): CAUTI remains the most prevalent complication, occurring at a rate of 3% to 7% per catheterized day. Prevention includes minimizing breaks in the closed system, using the smallest appropriate catheter size, and rigorous hand hygiene. Asymptomatic bacteriuria is common and should not prompt antibiotic treatment unless specific symptoms arise.

Encrustation and Blockage: Biofilm formation and encrustation affect nearly half of long-term catheter users, driven primarily by bacterial species like Proteus mirabilis. Regular catheter changes and home irrigation with saline can mitigate clogging. New research suggests aminoglycoside bladder instillations might reduce infection risk, but broader adoption remains limited.

Bladder Stones and Cancer Risk: Chronic catheter use elevates the risk of bladder stone formation and, over long periods (over 10 or more years), bladder cancer. Clinicians should maintain vigilance for hematuria in catheter-dependent patients, as it may signal malignancy.

Bladder Spasms and Bypass Leakage: Bladder spasms are common in catheterized patients and may cause leakage around the catheter. Management includes using oral agents like anticholinergics or β-3 agonists while monitoring for side effects like dry mouth, constipation, and delirium.

Urethral Erosion and Traumatic Hypospadias: Prolonged catheterization can lead to urethral erosion, creating complex management challenges such as traumatic hypospadias or full penile fileting. Prevention involves using appropriate catheter sizes, ensuring securement, and transitioning to suprapubic tubes when long-term drainage is necessary.

Alternatives to Indwelling Catheters

For long-term bladder management, suprapubic tubes are increasingly favored over urethral catheters, given their reduced risk of erosion and better patient comfort. Clean intermittent catheterization remains the gold standard where feasible.

Innovations such as external urinary collection devices (e.g., PureWick) for both male and female patients offer new avenues to manage incontinence without urethral instrumentation, reducing infection risk.

Team-Based Approach 

Catheter management should be a multidisciplinary effort, involving nurses, primary physicians, and urologists to optimize patient safety and comfort. Protocols for early catheter removal and ongoing reassessment of necessity can significantly reduce CAUTI rates and other catheter-related harms.

Clinicians are encouraged to refer to the American Urological Association's guideline "Indwelling Urinary Catheter Management of the Acute Patient," which offers detailed toolkits and resources to implement evidence-based practices.

Conclusion

While Foley catheters are indispensable in modern health care, their risks necessitate judicious use and meticulous management. By adhering to best practices in catheter selection, insertion, maintenance, and removal, clinicians can optimize bladder drainage while minimizing infections, trauma, and long-term complications. Alternatives should be considered whenever feasible, and a proactive team-based strategy is key to ensuring patient safety and improving outcomes.

Source: JAMA Surgery