Antimicrobial dressings are key in the highly complex treatment of patients with infected, chronic wounds. Following a treatment pathway that involves treating the underlying disease, applying these dressings on a clean wound when changing the dressing might help prevent and manage local wound infections. Their use also follows scientific and political efforts aiming at restricting the use of antibiotics. Especially in outpatient care, dressings with antimicrobial action in infected wounds and wounds at risk are of great advantage.
Chronic wounds* are a major public health challenge, and their relevance is steadily increasing due to the ageing of population and the parallel increase in chronic conditions such as diabetes mellitus, chronic venous insufficiency and peripheral arterial occlusive disease. As an example, in Germany in 2012, 2.7 million patients were diagnosed with wounds1. Among these patients, almost 900,000 had chronic wounds, meaning wounds that did not heal within eight weeks2. While the actual annual prevalence of these wounds remains unclear because of underreporting, a recent literature review estimated a prevalence of chronic wounds of mixed aetiologies of 2.21 per 1,000 people3.
As biofilm is a causal component of chronic wounds, prevention of biofilm formation and biofilm removal are of crucial importance for tackling the challenges of wound management. In fact, biofilm structures are found in up to 60% of chronic wounds and can significantly delay healing4. Therefore, physical removal, i.e. debridement of necrotic and contaminated tissue can effectively promote healing processes. An L&R study could show that following a biofilm pathway that included monofilament fiber debriding technology for mechanical debridement and local antimicrobial therapy could effectively promote wound healing in chronic wounds5.
Chronic wounds are more likely to occur in older adults because of physiological changes in the skin, vascular difficulties in wound healing and comorbidities. In this population, the effects of these wounds on quality of life are profound, especially when wound infections occur. In fact, infections represent significant challenges in the treatment of chronic wounds as they hinder healing processes and can even result in sepsis. Identifying wounds at risk of infection before clinical and serological signs occur is therefore crucial for optimising antimicrobial treatment and provides significant benefits for the patients.
The Wounds at Risk Score (W.A.R. Score), developed by an international, interdisciplinary panel of experts supported by L&R, allows clinicians to quickly assess the risk of infection taking into account the concrete patient conditions6. Different risk causes such as immunological status of the patient, underlaying diseases, type and localisation of the wound are weighted using a point system and the points are then added together. With three or more points local antimicrobial treatment is justified. In 2014, a German multicentre study examined the clinical application of the W.A.R. score in a group of 970 patients with chronic leg ulcers. This investigation demonstrated that the use of the score facilitates patient selection for prevention of wound infection7.
The diagnostics and treatment of chronic wounds remains however very complex and requires the involvement of experts from different medical professional groups to guarantee a necessary holistic approach. In order to provide further medical insights into therapeutic challenges and set general standards for treatment of infected chronic wounds, a panel of nine German and Swiss wound experts published a 2019 position paper titled “Treatment of Patients with Chronic Wounds: Focus Wound Infection in Outpatient Care.”8 Overall, preventing and managing wound infections is crucial to avoid complications, reduce the financial burden of complex treatments and improve quality of life.
In fact, more than 8 billion euros are spent annually in Germany for the care of chronic wounds9. One costly example is local wound infections, which occur when pathogens enter wounds and cause local inflammations. In fact, local wound infections are serious complications that can cause additional profound tissue damage and necrosis.
This is not the only complication from local wound infections. For example, the use of antibiotics for the local therapy of wounds should be avoided as their usage conflicts with current scientific and political efforts for targeted antibiotic treatment with strict indications. At the same time, the risk of an infection increases in patients with weak immune systems and in the presence of a high number of virulent microbes. For patients with venous ulceration, long-term compression therapy*, can help achieve healing rates as high as 97 percent as demonstrated in several randomized trials10.
Modern wound management strategies consist of a three-step approach* with debridement for preparing and cleaning the wound bed, wound treatment with the most appropriate dressing and compression therapy.
Chronic wounds can be treated in accordance with two principles:
When the bacterial load is low, dressings with passive germ elimination can be used to prevent infections. These dressings absorb the exudate along with the contained pathogens, and they reduce the number of microorganisms in the wound. Regular wound cleansing and frequent dressing changes can further increase the effectiveness of this approach. Active germ-killing dressings, however, are much more efficient in reducing the pathogen load in the wound and are indicated for delayed wound healing due to a high bacterial load or to treat local infections. Active dressings* are also preferred in outpatient care as they maintain their effectiveness over several days and can be worn for longer periods of time, e.g. when physical distance must be kept.
In line with current research, the authors of the 2019 chronic wound position paper recommend performing regular mechanical* or surgical debridement on wounds when biofilm is suspected.
The use of antimicrobial substances such as octenidine, polyhexanide or silver* can prevent recontamination and suppresses the formation of new biofilm11. The application of such agents should follow strict indications, such as during the cleansing phase or if there is an increased risk of infection, and regular checks should be performed. At the latest, 14 days after beginning of therapy, therapeutic success should be evaluated, and an eventual prolongation of the treatment should be considered12. Finally, in accordance with the 10-point plan from the German Federal Ministry of Health, systemic antibiotics should be used only when absolutely necessary, such as in case of systemic infections to combat resistant pathogens13.
Managing chronic wounds is challenging, and patients often have to face many obstacles before receiving adequate treatment of both chronic wounds and the underlying conditions. Even though most chronic wounds in Europe are of vascular origin, only about 25% of all patients receive vascular medical diagnostics14.
As one example, about 70% of patients with venous leg ulcers are treated exclusively by general practitioners and are usually referred late to specialists. In addition, patients have to face restrictions on their quality of life as they suffer from pain, wound odour and other symptoms such as sleep disorders, loss of mobility and social isolation. Infections of chronic wounds can also lead to loss of extremities, sepsis and even death.
Therefore, treatment of patients with chronic wounds should follow a systematic approach and should be provided through specialised, interdisciplinary networks to ensure favourable outcomes. Studies have shown that the implementation of guidelines and treatment pathways significantly reduces complication rates15. Although advances in wound-healing research are paving the way for the development of new treatment options, current wound patients benefit from increased access to multidisciplinary teams of wound-healing specialists.