What are the risks of intra-urethral Foley catheter balloon inflation in spinal cord-injured patients. How can urethral trauma be prevented during catheterisation. What are the key parameters for designing safer urethral catheter systems. How effective is a novel safety device in preventing urethral injury.

Understanding Urethral Catheterisation and Associated Risks

Urethral catheterisation is a common medical procedure, with approximately 25% of hospitalized patients requiring catheterization during their stay. However, this routine task can lead to serious complications if not performed correctly. One of the most significant risks is urethral injury, which typically occurs in men when the catheter’s anchoring balloon is inadvertently inflated inside the urethra instead of the bladder.

Complications arising from urethral injury can be categorized into short-term and long-term effects:

• Short-term complications:
  • Pain
  • Bleeding
  • Acute urinary retention
• Long-term complications:
  • Urethral stricture disease
  • Potential need for urethral reconstruction in severe cases

Investigating Urethral Strain Thresholds for Rupture

Prior to this study, there was a lack of research demonstrating urethral strain thresholds for rupture during traumatic urethral catheterisation. To address this gap, researchers aimed to investigate two key parameters:

1. Internal urethral diametric strain
2. Threshold maximum inflation pressure

These parameters were studied to determine at what point urethral rupture occurs during inadvertent inflation of a catheter anchoring balloon in the urethra.

Methodology of the Study

The research was conducted using the following methods:

• Inflation of urethral catheter anchoring balloons in the bulbar urethra of 21 ex vivo porcine models
• Use of 16 Fr catheters
• Characterization and grading of urethral trauma with retrograde urethrography
• Correlation of urethral rupture with internal urethral diametric strain (%) and maximal urethral pressure threshold values in kilopascals (kPa)
• Calculation of internal urethral diametric strain by averaging urethra luminal diameter proximal and distal to the traumatized site, and maximum luminal diameter at the traumatized site

Development and Evaluation of a Novel Safety Device

In addition to investigating urethral strain thresholds, the researchers designed and evaluated a novel safety device. This device was developed with the goal of preventing urethral trauma, even in cases of inadvertent balloon inflation in the urethra.

Testing the Safety Device

The evaluation of the safety device involved the following steps:

• Inflation of urethral catheters in the bulbar urethras of seven fresh male cadavers
• Comparison between a standard syringe and the prototype safety-syringe
• Standard syringe: Plunger depressed until opposing resistance pressure from the urethra prevented further inflation
• Prototype safety-syringe: Plunger depressed until sterile water decanted through an activated safety threshold pressure valve

Key Findings on Urethral Rupture Thresholds

The study revealed crucial information about the conditions under which urethral rupture occurs:

• Porcine urethral rupture consistently occurred at:
  • Internal urethral diametric strain >40%
  • Maximum inflation pressure >150 kPa

These findings provide valuable insights into the thresholds at which urethral injury is likely to occur, informing the development of safer catheterisation practices and devices.

Effectiveness of the Prototype Safety-Syringe

The evaluation of the prototype safety-syringe yielded promising results:

• Mean maximum human urethral threshold inflation pressure to activate the safety prototype syringe pressure valve: 153±3 kPa
• Mean maximum inflation pressure using the standard syringe: 452±188 kPa
• The difference between the two was statistically significant (p<0.001)

These results demonstrate that the prototype safety-syringe effectively limits the inflation pressure to a safer level, potentially reducing the risk of urethral injury during catheterisation.

Implications for Safer Urethral Catheter Systems

The study’s findings have significant implications for the design of safer urethral catheter systems. By identifying the critical parameters of internal urethral diametric strain and threshold maximum inflation pressures, manufacturers can develop catheters with lower intrinsic threshold inflation pressures, thereby reducing the risk of urethral trauma.

Transition from Bench to Bedside

The researchers have taken steps to validate their findings and implement the safety device in clinical practice:

• Validation of porcine and cadaver findings in human male-to-female transgender urethral models
• Implementation of the safety device into clinical practice at Tallaght Hospital, Dublin, Ireland
• Recognition of the bench-to-bedside transition at the European Association of Urology (EAU) in March 2017

Future Directions in Urethral Catheterisation Safety

The research presented in this study opens up several avenues for future developments in urethral catheterisation safety:

1. Further refinement of safety devices based on the established thresholds
2. Development of training programs for healthcare professionals to increase awareness of urethral injury risks
3. Integration of safety mechanisms into standard catheterisation equipment
4. Exploration of alternative catheterisation techniques that may further reduce the risk of urethral trauma
5. Long-term studies to assess the impact of safety devices on reducing catheter-related complications

Can urethral trauma be completely eliminated during catheterisation. While complete elimination may be challenging, the findings of this study suggest that significant reductions in urethral trauma are possible through the use of safety devices and adherence to established inflation pressure thresholds.

The Role of Healthcare Professionals in Preventing Urethral Trauma

Healthcare professionals play a crucial role in preventing urethral trauma during catheterisation. To enhance patient safety, consider the following recommendations:

• Proper training and education on catheterisation techniques
• Awareness of the risks associated with inadvertent balloon inflation in the urethra
• Familiarity with the use of safety devices and their importance
• Regular assessment of catheterisation practices within healthcare facilities
• Implementation of protocols that prioritize patient safety during catheterisation procedures

How can healthcare institutions ensure the widespread adoption of safer catheterisation practices. Institutions can promote safer practices by:

1. Implementing mandatory training programs for all staff involved in catheterisation
2. Regularly updating guidelines based on the latest research findings
3. Investing in safety devices and equipment that reduce the risk of urethral trauma
4. Conducting audits to monitor adherence to safety protocols
5. Encouraging a culture of open communication about catheterisation-related incidents and near-misses

Patient Education and Involvement

Empowering patients with knowledge about catheterisation can also contribute to safer practices:

• Providing clear information about the catheterisation procedure and its potential risks
• Encouraging patients to communicate any discomfort or concerns during the procedure
• Educating patients on proper catheter care and maintenance
• Involving patients in decision-making processes regarding their catheter management

Do patients have a role in preventing urethral trauma during catheterisation. While the primary responsibility lies with healthcare professionals, informed and engaged patients can contribute to their safety by being aware of the procedure and reporting any unusual sensations or concerns promptly.

Advancing Research in Urethral Catheterisation Safety

The study presented here marks a significant step forward in understanding and preventing urethral trauma during catheterisation. However, there is still much to be explored in this field. Future research directions may include:

• Investigation of urethral strain thresholds in diverse patient populations
• Development of advanced imaging techniques for real-time monitoring during catheterisation
• Exploration of materials science to create catheters with inherent safety features
• Studies on the long-term outcomes of patients catheterized with safety devices
• Economic analysis of the impact of reduced catheter-related complications on healthcare systems

How can technological advancements contribute to safer catheterisation practices. Emerging technologies such as smart materials, miniaturized sensors, and artificial intelligence could potentially revolutionize catheterisation safety by providing real-time feedback, automatic pressure regulation, and predictive analytics to prevent complications.

Collaboration and Knowledge Sharing

Advancing the field of urethral catheterisation safety requires collaboration across various disciplines and institutions:

1. Interdisciplinary research teams combining expertise in urology, biomedical engineering, and materials science
2. Partnerships between academic institutions and medical device manufacturers
3. International collaborations to study catheterisation practices and outcomes across different healthcare systems
4. Establishment of databases and registries to collect and analyze catheterisation-related data on a large scale
5. Regular symposia and conferences dedicated to catheterisation safety and innovation

What role do professional organizations play in promoting safer catheterisation practices. Professional organizations such as urological societies and nursing associations can significantly impact practice by:

• Developing and disseminating evidence-based guidelines
• Providing continuing education opportunities focused on catheterisation safety
• Advocating for the adoption of safer technologies and practices in healthcare settings
• Facilitating research collaborations and knowledge sharing among members
• Recognizing and promoting innovative approaches to catheterisation safety

Ethical Considerations in Catheterisation Research and Practice

As research in catheterisation safety advances, it is crucial to consider the ethical implications of new technologies and practices:

• Ensuring informed consent for catheterisation procedures and related research
• Balancing the need for innovation with patient safety
• Addressing disparities in access to safer catheterisation technologies
• Protecting patient privacy in the collection and use of catheterisation-related data
• Considering the environmental impact of disposable catheterisation devices

How can researchers and clinicians navigate the ethical challenges associated with catheterisation research and practice. By establishing clear ethical guidelines, involving ethics committees in research design, and maintaining open dialogue with patients and stakeholders, the field can progress responsibly while prioritizing patient well-being and safety.

The Future of Catheterisation: A Holistic Approach

As we look to the future of urethral catheterisation, a holistic approach that considers all aspects of patient care is essential:

1. Integration of safer catheterisation practices into comprehensive patient care plans
2. Consideration of alternative methods to manage urinary issues when appropriate
3. Focus on prevention of conditions that lead to the need for catheterisation
4. Development of personalized catheterisation strategies based on individual patient characteristics
5. Incorporation of patient feedback and experiences into the design of catheterisation devices and protocols

Can the need for urethral catheterisation be reduced in the future. While catheterisation will likely remain a necessary procedure for many patients, advancements in medical treatments, minimally invasive surgeries, and preventive care may help reduce the overall need for catheterisation, thereby minimizing the risk of associated complications.

Preventing Urethral Trauma During Catheterisation

Authors:

^*Niall F. Davis,^1,2
Rory O’C. Mooney,²
Conor V. Cunnane,²
Eoghan M. Cunnane,²
John A. Thornhill,¹
Michael T. Walsh²

1. Department of Urology, Tallaght Hospital, Dublin, Ireland
2. Centre for Applied Biomedical Engineering Research, Materials and Surface Science Institute, University of Limerick, Castletroy, Ireland
*Correspondence to: [email protected]

Citation:

EMJ Urol. 2017;5[1]:60-61. Abstract Review No. AR19.

Keywords:

Urethral trauma,
urethral catheterisation,
urethral rupture,
urethral injury,
urethral catheter,
safety device,
safety syringe

Each article is made available under the terms of the Creative Commons Attribution-Non Commercial 4.0 License.

Urethral catheterisation is a routine task that is frequently performed within a healthcare setting. Almost 25% of hospitalised patients are catheterised during their inpatient stay.¹ Urethral injury typically occurs in men when the catheter’s anchoring balloon is inadvertently inflated inside the urethra.² Short-term complications include pain, bleeding, and acute urinary retention.² Urethral rupture can lead to the long-term complication of urethral stricture disease and may require urethral reconstruction in severe cases.²

There are currently no studies that demonstrate urethral strain thresholds for rupture during traumatic urethral catheterisation. Our aim was to investigate internal urethral diametric strain and threshold maximum inflation pressure as parameters for urethral rupture during inadvertent inflation of a catheter anchoring balloon in the urethra. In addition, we also designed and evaluated a novel safety device with the inability to cause urethral trauma, despite inadvertent balloon inflation in the urethra based on these parameters.

Inflation of a urethral catheter anchoring balloon was performed in the bulbar urethra of 21 ex vivo porcine models using 16 Fr catheters. Urethral trauma was characterised and graded with retrograde urethrography. Urethral rupture was correlated with internal urethral diametric strain (%) and maximal urethral pressure threshold values in kilopascals (kPa). Internal urethral diametric strain was calculated by averaging urethra luminal diameter proximal and distal to the traumatised site, and maximum luminal diameter at the traumatised site. Urethral catheters were then inflated in the bulbar urethras of seven fresh male cadavers using a standard syringe and a prototype safety-syringe prototype safety-syringe (Figure 1). The plunger of the standard syringe was depressed until opposing resistance pressure generated by the urethra prevented further inflation of the anchoring balloon. The plunger of the prototype safety-syringe was depressed until sterile water in the syringe decanted through an activated safety threshold pressure valve (Figure 1).

Figure 1: The prototype syringe used to determine urethral resistance pressure. The safety valve (arrow) is activated at threshold resistance pressure, allowing fluid to vent out of the activated valve.

Retrograde urethrography demonstrated that porcine urethral rupture consistently occurred at an internal urethral diametric strain >40% and a maximum inflation pressure >150 kPa (Figure 2). The mean±standard deviation maximum human urethral threshold inflation pressure required to activate the safety prototype syringe pressure valve was 153±3 kPa. In comparison, the mean maximum inflation pressure was significantly greater using the standard syringe than the activated prototype syringe (452±188 kPa, [p<0.001]).

Figure 2: Maximum catheter balloon/urethral pressure and internal diametric strain recorded for each of the 21 urethral samples tested.
This figure clearly demonstrates a safety cut-off of >40% internal urethral diametric strain and/or maximum balloon pressure cut-off of 150 kPa before urethral rupture (red dashed lines). Open circles indicate ruptured urethral samples. Filled circles indicate unruptured samples.

Internal urethral diametric strain and threshold maximum inflation pressures are important parameters for designing a safer urethral catheter system with lower intrinsic threshold inflation pressures. We have validated our porcine and cadaver findings in human male-to-female transgender urethral models and have recently implemented our safety device into clinical practice in Tallaght Hospital, Dublin, Ireland for patients requiring urethral catheterisation. This transition of a safety device from bench to bedside was commended during my presentation during March 2017, held at the European Association of Urology (EAU) congress, hosted in London, UK.

References

Chenoweth C, Saint S. Preventing catheter-associated urinary tract infections in the intensive care unit. Crit Care Clin. 2013;29(1):19-32.
Davis NF et al. Incidence, Cost, Complications and Clinical Outcomes of Iatrogenic Urethral Catheterization Injuries: A Prospective Multi-Institutional Study. J Urol. 2016;196(5):1473-7.

Misplaced Catheter Causes Significant Urological Damage

This case involves a misplaced catheter resulting in serious, long-term urological damage.

On the date of the incident in question, the patient was admitted to the hospital undergo a hip replacement. Pre-surgery, the patient was anaesthetized, and the nurse attempted to place a Foley catheter. However, the Foley catheter balloon was inflated in the patient’s urethra instead of his bladder. The balloon remained in the urethra for hours, despite not producing a good return of urine, and the patient did not recieve a urology consultation. This misplacement necessitated a surgical procedure to implant a temporary suprapubic tube and additional surgery of the urethra. Due to this misplacement, the patient ultimately spent multiple days in intensive care and suffered permanent disability and disfigurement.

Question(s) For Expert Witness

1. Are you able to address standard of care/ongoing complications as it relates to using a Foley catheter improperly?

Expert Witness Response E-014220

I am very familiar with current standard of care for Foley catheter placement and management (especially for inpatients) and catheter related complications, such as trauma related complications and catheter associated UTIs (CAUTIs). I’m familiar with risk factors associated with catheter related complications (i.e. traumatic catherizations) which include but not limited to prior lower urinary tract surgery/procedure (ex. TURP, RRP/RALP etc), presence of urinary tract device, such as sphincter or sling, and prior lower urinary tract trauma or infections. In 2012 I was a member of a multidisciplinary committee at my institution addressing catheter associated complications, such as UTIs and traumatic injury due to placement of Foley catheter. Our committee’s findings led to significant changes in urethral catheter management in inpatients. Protocols were created for placement and subsequent management of Foley catheters for all inpatients. This included, specific to minimizing risk of traumatic catheterization, that the catheter balloon should not be inflated until the catheter is completely in and there is return of urine. Also, if the patient has risk factors for catheter related complications (as described above), developed blood per urethra upon initial attempts to catheterize, or requires a Coude cath (specialized catheter) Urology should be consulted. These are typically patients on trauma service, ICU/CCU, and surgical services. This often involves urgent or semi-urgent placement of a Foley catheter by a nurse or intern/junior resident in the ER, trauma unit, resuscitation bay, ICU or operating room. The malposition is not recognized for hours or days (and sometimes week(s)) later. The subsequent history usually involves blood/urine bypassing around the catheter and poor drainage/urine output via catheter. Significant number of these patients has encountered long term sequelae from the injury due to the inflation of the balloon within the urethra. This injury inevitably leads to a urethra stricture which typically requires treatment either endodcopically, i.e. urethral dilation and/or DVIU (incising the stricture) or surgical repair/reconstruction, what is known as urethroplasty.

FAQ

When and why is intermittent catheterization recommended?

Intermittent catheterization is an effective and safe urinary diversion method that offers patients independence and significantly improves quality of life. In recent years, intermittent catheterization has become the preferred method for managing patients with neurogenic bladder dysfunction, paraplegia, diseases such as spina bifida or multiple sclerosis.

The choice of method of intermittent catheterization is carried out only after this method is recommended by the doctor in each case. Catheterization is carried out by emptying the bladder at regular intervals with disposable catheters.

How is intermittent catheterization performed in children?

Children with neurogenic bladder dysfunction can be catheterized by a parent or healthcare professional, always using asepsis. Parents should ask their doctor or medical professional who will explain and demonstrate the correct catheterization procedure. Only by carefully preparing you can be sure that you are performing the catheterization procedure correctly.

For infants and small children, the following sizes are generally used: 2.0-2.7 mm (Ch06-Ch08).

How many times a day should the bladder be catheterized?

The normal frequency of emptying the bladder is approximately 56 times a day. The frequency of catheterizations depends on the individual and factors such as how much you drink, medication, etc. Your healthcare provider can recommend how often you need to catheterize your bladder. You can determine for yourself when and how it will be best for you to carry out catheterization.

How much fluid should you drink every day?

This may vary depending on how active you are. You should aim to drink about 1.5-2 liters of fluid per day. Try to avoid drinks that contain caffeine, such as tea or coffee.

What should I do if I have difficulty inserting a catheter?

Sit in a comfortable position, try to relax and wait a while before performing the catheterization procedure. If you are unable to insert the catheter on your own, contact your healthcare provider.

What if I have difficulty removing the catheter?

Try not to worry and wait a while before trying again. Coughing can sometimes help insert or remove a catheter.

Are there any signs or symptoms I should be aware of?

Don’t wait until your bladder is full. The following symptoms may indicate that your bladder is too full:

• tense and swollen lower abdomen,
• headache,
• feeling of heat and sweating.

What should I do if urine does not come out of the catheter?

If urine does not come out through the catheter, remove it and try a new one. Make sure the catheter is in the bladder. If you feel that your bladder is still full, check with your doctor.

Possible complications of intermittent catheterization

One of the most common complications of catheterization is urinary tract infection. There may also be blood in the urine, bleeding from the urethra, or difficulty inserting a catheter. If you have any of these signs, contact your doctor.

Other tips

The following is a list of symptoms that may indicate a urinary tract infection:

• burning sensation,
• fever,
• fever,
• bad smell of urine .

If you have any of these signs, contact your doctor.

Placement, replacement and care of the Foley catheter.

The structure of the bladder

Placement of the Foley catheter.

Hygiene procedures must be carried out before insertion of the catheter.

The specialist should wash the patient’s hands and perineum with soap and water, disinfect with an antiseptic, and put on sterile gloves. Prepare the catheter (take with sterile tweezers, treat with a lubricant if necessary).

Catheter insertion procedure for women:

Lying on your back, bend and spread your legs.

After parting the labia and finding the opening of the urethra, carefully insert the catheter. As soon as urine has gone through the catheter, you should stop.

After that, through one of the passages at the outer end of the catheter, inject sterile water with a syringe in a volume sufficient to inflate the balloon. Then attach the urine collection bag to the outer end. It is necessary to ensure that the bag is always below the level of the belt in order to avoid backflow of urine through the catheter.

Catheter insertion procedure for men:

Catheter insertion is more difficult for men. Since the urinary canal is longer and has physiological constrictions. The patient needs to lie on his back and slightly bend his knees, relax, the catheter is inserted into the urethra slowly and smoothly, with rotational movements, clamping the catheter with 5 and 4 fingers of the right hand, and first the genital organ must be held vertically, and then tilted down. Carefully advance the catheter. The presence of urine indicates that the catheter is placed correctly.

For children:

When placing a catheter, it is necessary to ensure the psychological comfort of the child.

Disinfect the genital area twice and wrap it with a sterile drape. Lubricate the end of the catheter, such as Vaseline.

Do not force the catheter if an obstruction is felt – this can damage the urethra.

The procedure for inserting the catheter is similar to that for adults, but the insertion depth is less because the urethra is shorter.

Urinary Catheter Care:

Wash the area around the catheter with soap and water several times a day to avoid irritating the infection. Do this after every bowel movement. Women are washed from front to back.

Drain the bag in time, keeping it below the level of the bladder to avoid urine flowing back into the catheter.

Change of catheter:

In case of normal urine outflow, the catheter is changed according to the recommendation of the doctor and instructions for use of the catheter.

Silicone have a shelf life of up to 30 days, latex up to 7 days, silicone with silver up to 90 days.