WOUND INFECTION

There are classic signs and symptoms that are easily identifiable as wound infection, but not all wounds will exhibit all these signs at any one time. Localised infection is often characterised by the classic signs and symptoms of inflammation, pain, heat, swelling, redness and loss of function (WUWHS, 2008). Additional criteria have been suggested for identifying wound infection, which include:

For healing to proceed it is important to prevent the establishment of localised infection and spreading infection. This may involve the prevention of progression to colonisation or the management of an established localised infection (WUWHS, 2016).

The indiscriminate use of antibiotics has made resistant organisms more prevalent. The use of antibiotics is not recommended because of the development of bacterial resistance, allergic and sensitivity reactions (Sussman et al, 2014).

Wound swabbing is still recommended if there is suspicion of wound infection and is used to determine the most appropriate systemic antibiotic to be prescribed (Sussman et al, 2014). Topical antiseptic/antimicrobial agents such as honey, silver, polyhexamethylene biguanide (PHMB) and iodine are currently widely used in the prevention and management of infection, within the WBP concept. Without WBP, certain patients may be at risk of untreated infection in the wound, which may progress to sepsis (EWMA, 2006).

Topical antiseptic/antimicrobial agents represent the first-line treatment in the management of bacterial burden as they provide a high concentration of the agents at the site of infection (Cutting et al, 2005). Wounds exhibiting signs of increased bacterial burden, wounds that are at risk of bacterial contamination and wounds in immuno compromised patients should be considered for antimicrobial dressings. Topical antiseptic/antimicrobials are recommended as they have a broad spectrum of antimicrobial activity and antimicrobial resistance is rare in human pathogens (Cutting and White, 2004).

The 2-week challenge rule (Wounds UK, 2010) should apply to determine the duration of the use of an antimicrobial dressing. In wounds that are thought to be critically colonised, a topical antimicrobial agent may be considered.

The selection of the appropriate wound management product should be done following the assessment of tissue types present, the level of exudate and patient comfort. Failure of the wound to improve after 2 weeks is an indicator to change to a different dressing and/or add an appropriate antibiotic if signs of infection are progressing (Wounds UK, 2010). The prevention and management of infection and biofilms in chronic wounds is a primary objective. The treatment goal must be to reduce the bioburden and/or eradicate potential biofilm in the wound bed. The incorporation of a method of aggressive wound debridement will help control bacteria biofilms, suppress biofilm regrowth, disrupt the microbial burden and promote wound healing (Sussman et al, 2014; Swanson et al, 2014).

ACTIVHEAL PHMB FOAM CLINICAL EVALUATION

Methods
The evaluation of the ActivHeal PHMB foam was undertaken over four sites within the UK, to observe the clinical outcome and gain clinician’s opinion of the dressing. The study design was a product evaluation, where the dressing was used within the standard practice delivered by the centre. This was the preferred design to generate information on a range of patients and wound indications, some of which may be excluded in a more controlled study, and to observe current practice when antimicrobial dressings are used.

Within this design, the clinicians were not restricted by a protocol to control the process but were provided with guidelines that included information on the dressing, the inclusion and exclusion criteria and the maximum length of time for the evaluation, which was 4 weeks. Inclusion and exclusion criteria for selection to the evaluation was as follows:

Inclusion criteria:

• Males or females, aged 18 years or above (females must not be pregnant and if of reproductive age should be using contraception)
• Patients who were able to understand and give informed consent to take part in medical treatment
• Patients that had wounds that were infected or at risk of infection.

Exclusion criteria:

• Patients who declined the invitation to take part
• Patients who were known to be non-compliant with medical treatment
• Patients who were known to be sensitive to any of the dressing components.

A copy of the guidelines was attached to the case report form that included a form for the clinician to sign before the patient was included, to con rm the consent of the patient. The patients were not randomised to treatment and no additional interventions were made to standard care, therefore, ethical approval was not required. Organisational consent was obtained along with patient consent.

The ActivHeal PHMB foam was applied to wounds that were assessed as requiring an antimicrobial dressing. These included wounds in which the clinician had assessed infection to be a risk factor, or had observed signs and symptoms that a localised infection may be developing. The primary outcome of the evaluation was to assess the ActivHeal PHMB foam in promoting healing through the management of wound exudate and maintenance of a moist wound environment, as well as controlling the wound bioburden in the management of the following wounds; leg ulcers, diabetic ulcers, pressure ulcers and post- operative surgical wounds. Wound size, wound bed status, exudate levels, peri-wound condition, wound pain, along with the clinical signs and symptoms of infection, were the outcomes measured. The following were evaluated to assess dressing performance: ease of use, conformability to the wound, patient comfort during removal and wear, clinician satisfaction and its ability to stay in place.

Results
The ActivHeal PHMB foam was evaluated on 32 patients. The patients treated were those attending the outpatient services. The age of patients ranged from 46-91 years and wounds were of moderate to high exudate levels. Tissue types were necrotic, sloughy and granulating.

At the end of the evaluation period, 7 wounds had progressed to healing and 14 had progressed significantly to a different wound care product. The other 11 were still receiving the treatment of PHMB foam. No wounds increased in size, and there were positive changes in wound dimensions observed. There was a noted reduction in pain reported by all patients and a trend towards lower levels of exudate was seen in the majority of wounds assessed. These results suggest that the foam dressing effectively managed exudate levels and maintained a moist wound environment.

CASE STUDY PATIENT 2

Initial assessment found the wound to be 4cm in length and 4.5cm in width, with moderate exudate, from which there was a purulent discharge. The wound had 40% slough and 60% granulation tissue. The wound showed signs of infection and discolouration of the wound bed, purulent discharge, pain and tenderness and redness/erythema to the surrounding tissue (Figure 4a). The PHMB foam was selected to assist in reducing the wound bioburden and reduce the signs and symptoms of infection as well as to manage and absorb levels of exudate, maintain a moist wound environment, and promote healing.

The wound was reviewed a week later (Figure 4b) and significant progress was then noted in the wound; it was reducing in size and showing positive signs of healing. Areas of slough had reduced and new epithelial tissue was apparent. The peri-wound skin remained intact indicating that the PHMB foam was managing the levels of exudate. The colour of discharge had changed and was less purulent. The clinical signs and symptoms of infection had reduced, with less erythema and pain. The PHMB foam was reapplied.

The wound was reviewed and reassessed at week 3 (Figure 4c) and the wound had reduced further in size and was continuing to heal. Areas of slough had reduced further and healthy granulating tissues was observed along with further areas of new epithelial tissue. The wound was now measuring 3cm long and 4cm in width. Exudate levels were reducing. The peri-wound skin remained intact indicating that the PHMB foam was managing the levels of exudate. No clinical signs of infection were noted. The PHMB foam was discontinued and replaced with a non-antimicrobial foam.

Case study 2 conclusion

ActivHeal PHMB foam dressing was found to be an appropriate dressing producing positive outcomes for the patient with this longstanding wound. The role of the foam as the carrier dressing was relevant, as wounds where the bioburden rises are most likely to demonstrate an increase in exudate. Despite the patient having a complex wound; size, exudate level and excoriation to the surrounding tissue all reduced. The wound also presented no evidence of bacterial bioburden, and the wound bed had improved, with a reduction in wound dimensions and growth of both new epithelial and granulation tissue. Therefore, ActivHeal PHMB foam was not only able to manage the exudate, it also achieved a moist wound environment at the wound bed, along with the removal of harmful bacteria from the wound surface and absorption into the core of the foam dressing. This suggested that ActivHeal PHMB foam can manage bioburden and maintain the moisture balance in the wound bed, addressing two of the barriers to healing within the WBP framework. This case study illustrates the importance of a holistic approach when caring for a patient with a challenging wound and ensuring that the dressing selection is made based upon a thorough assessment, ultimately ensuring good clinical outcomes for the patient.