Chronic, slow-healing wounds are a worldwide silent epidemic. Each year, approximately 34.5 million chronic wounds are reported globally, with over 200,000 in the UK alone. Most people never think about wounds until they suffer from one. Unfortunately, aging combined with conditions like diabetes or obesity either cause or exacerbate this malady.
Until recently, wound-care clinicians have had to rely on their experience, sight, smell and intuition to decide how to treat these wounds; unfortunately, there are often no visual cues to alert specialists to a problem.
The arrival in January 2012 of the world’s first point-of-care diagnostic test for wound care finally allows clinicians to choose appropriate and meaningful therapies early in the treatment regime, thus bringing wound care into the 21st century.
Wounds that are stalled or slow to heal can have a biochemical imbalance, resulting in excessive and damaging inflammatory protease activity, thereby hindering the natural healing process. Advanced therapies designed to reduce elevated protease activity (EPA) are available, but there are no visual cues to detect this imbalance.
The use of a point-of-care diagnostic tool able to identify an underlying cause of non-healing can lead to early and targeted treatment of the right wound at the right time, potentially avoiding the frustration and suffering so often associated with recalcitrant wounds. Such a device has recently been introduced across Europe, South Africa and the Middle East.
Protease activity
Although proteases are recognised as a key marker in wound healing, EPA in chronic wounds has so far gone undetected, as it presents no visual cues; however, EPA in chronic wounds can have a significant impact on healing.
A recently published study showed that chronic wounds with EPA have a 90% probability that they will not heal without appropriate intervention. It is estimated that over 30 million chronic wounds are treated each year, accounting for ≈3% of total health expenditure.
Until now, with almost 30% of non-healing wounds potentially having EPA, the absence of a rapid point-of-care diagnostic test could be increasing costs and morbidity due to ineffective treatment choices.
"Evaluation and assessment are the first steps that every wound-care clinician should take when presented with a chronic, hard-to-heal wound, but up until now, we have not benefitted from innovation in this field," says Professor Keith Harding of the School of Medicine, Cardiff University, UK, and chair of the International Consensus on ‘The role of proteases in wound diagnostics’. "The effective use of a point-of-care test for protease activity has the potential to revolutionise wound care globally."
Potential impact and the NHS
With the introduction of a diagnostic test to identify EPA, the UK’s National Health Service (NHS) could potentially save millions of pounds spent on ineffective wound care. The NHS has recommended assessment for EPA using a diagnostic test to help determine the treatment pathway for venous leg ulcers.
The guidance developed by NHS commissioners, clinical experts and Department of Health officials is intended to foster improvements in the way that leg ulcer services deliver care to patients within the NHS. The guidance clearly identifies EPA as a complication known to reduce healing rates.
Professor Michael Clark, chief executive of The Lindsay Leg Club Foundation, commented on the expected impact this service specification could have on the way leg ulcers are managed in the NHS in the UK.
"It is interesting to see that the Department of Health is considering the use of EPA as a signpost for the subsequent care of people with venous leg ulcers.
"The scientific basis of wound healing is rapidly emerging, and all steps are translating laboratory results into diagnostic tools. From these, the selection of clinical interventions will be welcomed by the tissue viability community."
In the hospital The tissue viability service at Brentwood Community Hospital, part of the North East London NHS Foundation Trust, became the first within the healthcare service to use a diagnostic test for chronic wounds.
"Wounds are an often overlooked area of healthcare," says Ray Norris, clinical nurse specialist for tissue viability at the trust. "But for those who experience them, they can have a devastating effect on quality of life. Some wounds take years to heal. This new test can be used on patients who have a slow-healing wound and it quickly helps healthcare professionals select the best treatment option to speed healing. It’s a very exciting development."
The first patient tested at the hospital suffered from bilateral venous leg ulcers for several years. The patient’s test result was ‘low’, meaning it was likely that there were other underlying causes preventing the wound from healing. In this case, additional assessment is required to determine other potential causes of non-healing and what additional therapies might be required. An ‘elevated’ test result would have indicated the appropriateness of a protease modulating therapy.
Venous leg ulcers
Leg ulcers are common, affecting ≈1% of the population worldwide. As much as 60% of ulcers exist for a period of six months or longer (around one in three can persist for over a year). In the UK alone, venous leg ulceration is estimated to cost the NHS £300m-600m a year.
The underlying cause of venous ulcers is predominately venous hypertension. Risk factors include increasing age, obesity, a sedentary lifestyle or immobility, in addition to deep vein thrombosis and varicose veins.
Many patients with leg ulcers remain part of a vicious cycle of pain, disability and isolation, with recurrent dressings and bandages a way of life. Early identification of potential healing impediments using diagnostic tools is critical.
NHS guidance recommends testing venous leg ulcers for EPA using a diagnostic tool as one of several assessment criteria. This could drive specific care pathways for ‘complex’ venous leg ulcers, distinct from those regimes recommended for ‘simple’ wounds.
The test represents a major development in the way wounds are cared for, and many patients with venous leg ulcers may finally see the benefits of early and targeted treatment enabled though the detection of EPA as part of a routine wound assessment.
Diabetes and diabetic foot ulcers
According to the World Health Organization (WHO), the prevalence of diabetes for all age groups worldwide is estimated to rise from 2.8% in 2000 to 4.4% in 2030. The total number of people with diabetes is projected to increase from 171 million in 2000 to 366 million in 2030.
In the UK, the cost of diabetes care and complications is 10% of all NHS budgets. It is estimated that 15% of people with diabetes will ultimately develop a foot ulcer in their lifetime, representing an annual incidence in at least 2.2% of people with diabetes. In the US alone, this translates to 3.6 million ulcers.
The WHO report found that over 60% of non-traumatic lower limb amputations occurred in people with diabetes, and, in 2004, 71,000 such amputations were performed on this population. Therefore, there is a need to develop improved diabetic ulcer treatments that can reduce amputation rates. The study found that comprehensive foot care programmes could reduce amputation rates by 45-85%. This may be further reduced by the addition of a diagnostic wound test.
"Sores and wounds for people with diabetes are serious, no matter how small or superficial they may appear," says Jacqui Fletcher, senior lecturer at the Wound Healing Unit at Cardiff University. "Making sure that patients get the right treatment as quickly as possible, wherever they are seen, is crucial. For people with a diabetic foot ulcer, knowing that their clinician is able to quickly and easily perform a diagnostic test wherever they see them should give them confidence that they are receiving the best quality care."
Point-of-care diagnostics
Chronic non-healing wounds pose a serious health threat, and require special treatment and care to avoid serious infection or even amputation.
The number of chronic wounds is expected to increase dramatically as the population ages, and the incidence of diabetes and obesity grows. Simultaneously, healthcare costs continue to rise to rates that are unsustainable.
Fletcher recently stated that the introduction of diagnostic tests means doctors and nurses now have a way of showing whether or not a more expensive dressing would help.
"It is important because a wound dressing will typically be replaced every other day, or a couple of times a day if the wound is wet, and so the cost of inappropriately used dressings can soon mount up," she explains.
The arrival of point-of-care diagnostics for wound care has the potential to immediately influence treatment decisions and help clinicians target advanced wound care therapies more effectively by identifying when EPA exists in chronic wounds. These innovative advances mark the arrival of ‘personalised’ medicine for 21st-century wound care.
