Doctors in the Dark

10 April 2008 (Last Updated April 10th, 2008 18:30)

Effective new treatments are now available for hard-to-heal wounds. But diagnostic tests must be developed that can help identify appropriate applications for these treatments if they are to fulfil their full potential. Jim Banks reports.

While many wounds need only short-term care, others can prove difficult to treat if infection sets in. Some infected wounds, if treated too late, can then become resistant to treatment, resulting in greater patient suffering.

Chronic wounds, such as venous leg ulcers or diabetic foot ulcers, are considered expensive to treat. As a result, treatment may be inadequate or slow. At the same time, treatment is often decided at the point of care, when the wound is initially presented, and the healthcare professionals delivering treatment at this stage often don"t have the right tools to derive a thorough therapeutic indication.

"People won't want to inappropriately use a wound care product that costs £120 when a cheap one will do – it is a very expensive decision to get wrong."

Again this can result in inappropriate care and a delay in administering proper treatment. So believes Professor Peter Vowden, consultant vascular surgeon and visiting professor in wound healing research at Bradford Teaching Hospitals NHS Trust and University.

"Wound care might be a small proportion of the cost of treating a medical condition, but if you put chronic wounds together, they certainly cost a lot to treat," says Vowden. "Wound care is not glamorous, so we don't have a tsar of wound care as we do for cancer care. Obviously, cancer is a more serious illness, but the NHS treats more patients for wounds than anything else, and wound care needs to be looked at as a whole."

Diabetic ulcers are a case in point. Wound care may be a relatively small element of the total cost of diabetes care, but the sheer number of cases means it is important to manage these ulcers cost-efficiently, and improve care and the patient experience.

"Wounds occur across a huge variety of medical disciplines, so the costs are easily lost," says Vowden. "Diabetic foot ulcers, for example, are hard to separate from the overall cost of diabetes care, but over a quarter of diabetic admissions are for foot ulcers.

Similarly, we have no idea of the cost of ulceration in rheumatoid arthritis, which often leads to many non-healing ulcers. This masking of costs is especially true in the UK, where a lot of wound care is given by nurses with no significant medical input."

THE RIGHT TOOLS IN THE RIGHT HANDS

Vowden recognises that nurses offer high-quality care at the initial treatment stage, but they are not trained in the diagnostic skills that can make all the difference in how a wound develops in the long term. Hard-to-heal wounds (see box) increase the cost of care and cause great discomfort to patients, and the way to avoid them is to improve early diagnosis of chronic wounds.

To provide timely care by bringing doctors in at the stage of initial care is impractical and unnecessary, so the logical solution in the UK is to give nurses simple, practical tools to help them establish whether a wound needs more than a simple dressing. A better diagnosis results in better care and an improved outcome," says Vowden. "The next generation of products in wound care must include a test to indicate which product to use.

"At the moment, there are very few diagnostic tools in wound care. For chronic wounds, we can measure bacterial and microbial changes in a laboratory, but not instantly. There are very few point-of-care diagnostic tests other than a visual inspection by the nurse."

Currently, a swab to test for an infected wound takes between 48 and 72 hours to be processed. This is obviously far too long for the results to have any effect on the initial treatment.

"The next generation of products in wound care must include a test to indicate which product to use."

"A test for anaemia will be back in five minutes," says Vowden. "For wounds, there are no clinical grounds to indicate antibiotic or antimicrobial treatments. There is no data on which to base the treatment, so the nurse or doctor must treat it blind. Wound care is crying out for a simple tool for therapeutic prediction to support decisions at the point of care.

Given the obvious need for such a test, Vowden has set out to develop a test himself. His work is taking into account a range of key factors, including inflammatory markers, wound acidity and rates of bacterial change. He believes that workable tests will be available in the foreseeable future.

Until such tests reach the market, wounds will most likely be treated using cheaper dressings, which in some cases will deprive patients of the benefits of the more sophisticated wound care products now available.

COST AND CAUTION

One trend in the healthcare sector that Vowden believes must be maintained is progress away from the use of cheap, simple dressings towards more sophisticated products that may incorporate additional therapeutic agents. But while this trend is promising, in that it has the potential to dramatically improve wound care and reduce the incidence of hard-to-heal wounds, it is being slowed by cost concerns.

The problem, says Vowden, is that we are moving away from the use of simple, inexpensive dressings, which are not particularly interactive with the wound, towards more complex, expensive dressings, which can deliver growth factors to the wound or which incorporate skin grafts. This means that we must understand the type of wound we are dealing with, so that we can use these dressings effectively. People won't want to make the mistake of inappropriately using a wound care product that
costs £120 when a cheap one will do – it is a very expensive decision to get wrong. So as more effective and expensive products become available, a diagnostic structure needs to be put in place.

If advanced dressings are used without tests for specific therapeutic indications, their application will not always be appropriate, and some products may have their reputations damaged. There are many advanced dressings available, but the image of many promising products has suffered after it has seemingly failed to live up to its performance in clinical trials when it has been widely used in the market.

One example of such a product, says Vowden, is Apligraf. Apligraf is made from living human fibroblast cells and is used to treat venous leg ulcers and diabetic foot ulcers alongside standard compression therapy. The product accelerates the body's healing process. In 1998, it became the first bio-engineered cell therapy to receive approval from the US Food and Drug Administration (FDA). The product has a lot to recommend it, but it fell into an expectation trap.

"Wound care is crying out for a simple tool for therapeutic prediction to support decisions at the point of care."

Vowden believes Regranex is another product that has been unjustly criticised. Regranex Gel is the only FDA-approved prescription medicine to contain platelet-derived growth factor, which again accelerates the healing of diabetic foot ulcers.

Vowden makes it clear that with these two treatments the problem was not with the products themselves, which are of high quality, but with the way they were used at the point of care.

"In clinical trials, these products were skilfully used," says Vowden, "but on general release they were used by less skilled people and did not yield the same results. Good products can get a bad name."

The result of all this is a reticence among clinicians to use more expensive advanced dressings in case they are wasting money – after all, it is better to make a £2 mistake than a £200 mistake. This makes dressing manufacturers less willing to develop the next generation of sophisticated products, as they cannot guarantee a return on their development costs. Ultimately, patients suffer for the lack of simple, practical testing tools to improve the use of sophisticated
dressings.

CHRONIC SITUATION

The likelihood that a wound will become hard to heal depends greatly on the first stage of care. If an infected wound is not given appropriate treatment, the number of senescent cells in the wound will increase, which makes the wound less responsive to treatment and, therefore, harder to heal.

In an inflamed wound you can measure matrix metalloproteinas (MMPs) and elastase levels, which are markers of infection. Then you can look at whether you have a dressing that can treat it. Matrix metalloproteinas (MMPs) are structurally related, zinc-dependent, neutral endopeptidases, which can degrade components of the extracellular matrix. The enzyme elastase is produced during inflammation and breaks down elastin fibrils in the skin.

Dressings now exist that can deliver MMP blockers and provide a moist wound healing environment or deliver growth factors, but as dressings become more complex, it is vital that they are used correctly.

"If the inflammation is extensive, however, you may not want to put growth factors on," says Vowden. "So you need both the dressing and the diagnostic tests to indicate when to use them."

CHANGE ON THE HORIZON

For Vowden, the ideal future scenario is for simple testing tools to be put in the hands of nurses to improve therapeutic indications. For him, cost savings are not the only priority, as the tests could in themselves be cost neutral and would still free up healthcare professionals for more important tasks and improve the quality of care. Ultimately, Vowden would like to see the tests enable patients to take more control of their own care.

"Patients suffer for the lack of simple, practical testing tools to improve the use of sophisticated dressings."

"A lot of wound care could be done by patients themselves," says Vowden. "If patients have a simple test to indicate that the wound just needs a new dressing, why would they go to the doctor?"

Vowden would like to see clinicians, diagnostic test developers and manufacturers of advanced dressings come together to ensure that the right products, skills and procedures combine at the point of care. "In about two years, these point-of-care tests will be available," he says. "What will be important then is to ensure that the tests we design lead to a useful event for the patient."

More accurate diagnosis, better care and greater cost efficiency are almost within reach. Tests under development will mean fewer dressings are used inappropriately, so that care providers can use sophisticated new dressings with confidence.