Bladder ultrasound imaging needs trained practitioners

Bladder volume scanning is now commonplace in hospitals throughout the UK, its widespread use fuelled by the availability of increasingly sophisticated portable ultrasound equipment. In an age when there is so much emphasis on evidence-based medicine, ultrasound scanning of the bladder remains largely unregulated. There is no obligation or requirement for formal training, and little by way of guidance for would-be practitioners.

In some hospitals, auxiliary nurses are expected to use bladder scanners without any training whatsoever, and without any real idea about how to calculate a post-void residual volume.

To all intents and purposes, currently available training in the NHS is virtually non-existent. Many hospitals rely on the “See one, do one, teach one” philosophy, with no formal training whatsoever. What training there is will often be given to individuals with no background in ultrasound and/or little anatomical knowledge. Such a strategy is wholly inadequate.

It requires a multi-disciplinary approach – not only radiology and medical physics, but urology, infection control and other interested parties – to provide agreed training schedules.

Ideally, bladder ultrasound practitioners should have a pre-designated skill level, achieved through approved and accredited training. Their day-to-day scanning practice should be regularly audited. Training should be delivered by a healthcare professional (HCP) with a technical background in imaging i.e. a radiographer/sonographer or medical physics technician.

Traditionally, medical physics personnel and radiographers have ruled the roost over the scanning domain. With some justification, perhaps, they and their professional bodies have expressed concern about the use of ultrasound equipment by untrained “outsiders”.1,2

As a result, they have been reluctant to sanction the use of bladder scanning equipment by other HCPs – in particular, the urology nurses and continence advisors whose patients would most benefit from its non-invasive investigative potential. However, they may also have failed to appreciate that bladder ultrasound is now a highly mobile technology. If it is to be truly cost-effective and clinically beneficial, it needs to be available on the wards and in the outpatients clinics, in the community or patient’s home – not static and inaccessible in a radiography department.

Not surprisingly, therefore, there still appears to be a great deal of uncertainty about what could be a potentially beneficial intervention for many thousands of patients with bladder dysfunction.

TRAINING VOID

Manufacturers of bladder ultrasound scanners have had to fill the training void left by the NHS.

Since July 2005, I have helped to supervise a number of training workshops sponsored by Bard Limited. These one-day courses have attracted widespread interest from urology nurses and continence advisors.

The main aims of the course are not only to provide HCPs with a basic knowledge and understanding of ultrasound technology for bladder scanning, but to explain why this technology plays a vital role in continence and bladder dysfunction assessment and the benefits it can bring to both PCT and NHS hospital Trust environments.

The course recognises that newcomers to bladder ultrasound scanning have a number of training requirements, and this is reflected in the expected learning outcomes, which include the following:

• A basic understanding of ultrasound physics.
• The ability to scan and measure residual urine volumes accurately and confidently.
• Ultrasound image recognition and interpretation of bladder abnormalities.
• The bladder scanning practitioner’s boundaries of responsibility and liability.

From a technical perspective, it is important that course participants understand that bladder ultrasound imaging is a non-invasive alternative to catheterisation – once considered the “gold standard” but uncomfortable for the patient and associated with an increased risk of urethral trauma and urinary infection.

Indeed, ultrasound scanning has been much simplified recently by the development of intelligent software that automatically calculates an accurate volume of residual urine as the procedure is taking place.

As an introduction to the use of this state-of-the-art “real-time” ultrasound, it is emphasised from the outset of the course that these scanners are specifically designed to measure the volume of urine in the bladder. While images may reveal abnormalities, the extent of the practitioner’s responsibility is to refer the patient to personnel more qualified to perform a diagnosis.

Correct interpretation of the ultrasound image, therefore, is a critical factor, with the emphasis on the following criteria:

• Recognising normal ultrasound bladder anatomy, as well as any abnormal changes that may be taking place.
• A basic understanding of the pathology of the bladder (e.g. bladder wall thickening due to inflammation or bladder cancer).
• A working knowledge of differential diagnoses (e.g. enlarged prostate, acute inflammation, calcification, diverticuli, bladder stones, dilated ureter).
• The need to assess both longitudinal/ sagittal and transverse images of the bladder for optimal results.

When to make appropriate referrals. Although a single ultrasound image is never conclusive, the sequence of images made possible with B-mode “real-time” scanning reduces the risk of diagnostic error. If in doubt, a re-scan should be requested, in the ultrasound department, to confirm or exclude bladder pathology, in conjunction with other measures (e.g. cystoscopy, blood tests, rectal examinations and plain or contrast radiography). It can be more difficult to obtain a good ultrasound image with older and obese patients, or those who may have scar tissue from previous surgical procedures.

One of the main advantages of a course such as this is that with the help of volunteers, many of the practical aspects of bladder scanning can be dealt with, including step-by-step guidance throughout the procedure. For example:

• Correct positioning of the patient will help to give reproducible and consistent imaging data.
• Scanning both longitudinal/sagittal and transverse images.
• Knowing what to look for – it can be distracting to look at everything in the visual field.
• Orientating the probe to the bladder in order to obtain an optimal image. • Applying sufficient pressure with the probe to obtain good contact.
• Scanning backwards and forwards across the bladder – not just at a selected point.
• Reinforcing anatomy skills – knowing where is the bladder in relation to other nearby organs (e.g. uterus, ovaries, prostate).
• Taking steps to ensure hygiene and infection control standards are met.

The workshop also addresses issues that come under the general heading of “professionalism”. This includes:

• Respect for the patient – making sure he or she understands the procedure.
• Explaining to patients that the ultrasound examination will not cause them pain or discomfort.
• Obtaining patient consent (oral consent is probably sufficient, although some specialists do suggest that written consent is advisable).
• Referring to local policies in the event of a patient unable to give consent (e.g. dementia, learning disabilities).
• Considering the need for a chaperone.
• Keeping a written record of each ultrasound examination.
• Referring to the patient’s GP or local urologist in the event of unexplained pathology or pathology that is clearly not related to bladder dysfunction.

Then there are other issues, such as the need for a maintenance programme:

• A maintenance programme should be in place with the manufacturer of the ultrasound equipment.
• Scanners should be regularly checked and calibrated. A record should be kept in the logbook of all tests carried out by the engineers, together with any faults and action taken, to ensure quality assurance.
• Contingency plans must be in place in the event of a scanner that is likely to be out of commission for any length of time (e.g. servicing/recalibration/unforeseen fault).

Finally, there is the question of financial management: a business plan for purchasing/maintaining scanners should include the following:

• Equipment costs (capital allowances).
• Maintenance costs (planned preventative maintenance).
• Gel/accessories costs.
• Insurance costs.
• Product life (e.g. cost of replacement scanners).

As it is increasingly difficult to obtain funding for running a bladder scanning service within the NHS, consider approaching medical charities, voluntary organisations (especially those whose members might be expected to be most aware of bladder dysfunction and other continence problems).

Of course, training workshops such as this are only the starting point. Ideally, there should be a structured programme of further training that includes:

• Practical experience in the use of ultrasound, under the guidance of a competent HCP.
• Carrying out a minimum of eight clinics (four to six patients per clinic) and completing a logbook of 50 patients.
• Tutorials to assess practitioners’ progress and to assess extent of clinical competence.
• Patient handling and administrative skills.
• Quality assurance and recognition of scanner faults.
• Final evaluation of clinical competency (preferably carried out by an independent assessor).

However, lack of trained supervisors in the UK is a problem, and a programme such as that outlined above is probably only available in one or two areas of the UK. Other practitioners would be best advised to work in tandem with a colleague, monitoring each other’s scans.

CONCLUSION

It is often claimed that “limited skill is required” to operate the latest generation of portable ultrasound bladder scanners. However, the potential for error still exists, especially if the practitioner’s anatomical skills are lacking. While bladder scanning may not be particularly complicated, it does require a structured approach. Professional standards in bladder ultrasound scanning will only improve with rigorous training, and the recognition that it is neither safe nor clinically advantageous to operate without the safeguard of appropriately trained practitioners.

And that as with so many other areas of clinical expertise, it is all down to practice, practice, and yet more practice.  

REFERENCES

1 Health Protection Agency (2005) Press statement. Risks of Ultrasound and Infrasound. www.hpa.org.uk

2 UK Association of Sonographers (2005). Practice regulation project. www.ukasonographers.org

Sue Allison
Sue Allison is an applications specialist, ultrasound, based in the North-West of England. She has a BSc in radiography from Queen Margaret University College, Edinburgh, and works closely with the manufacturers of ultrasound equipment to promote training of healthcare professionals in the North of England and Scotland.