Oxyzyme and Iodozyme 2-layer hydrogel wound dressings with iodine for treating chronic wounds

CE marking

The Oxyzyme and Iodozyme dressings received CE marks in 2006 and 2007 respectively, and are class III medical devices, incorporating a medicinal substance. The current Declaration of Conformity was made by Archimed in 2011, for 'Oxyzyme sterile wound dressing with iodine' and 'Iodozyme sterile wound dressing with iodine'. The dressings are now manufactured by Crawford Healthcare.

Description

Oxyzyme and Iodozyme dressings are used on external wounds. They comprise a 2‑component, hydrogel layer, which releases iodine and oxygen at the wound surface. The 2 sterile components are supplied in individual white pouches with easy peel tabs:

The first layer of the Oxyzyme and Iodozyme dressings contains glucose and potassium iodide and is placed directly on the wound. The second layer, containing glucose oxidase, is placed on top of the first. Atmospheric oxygen diffuses into the outer second layer, producing hydrogen peroxide. This diffuses into the first layer, producing molecular iodine (Davis et al. 2009, Wood et al. 2010). The layers must be placed in the correct order on the wound.

The Oxyzyme and Iodozyme dressings must be covered with an additional dressing that is permeable to air to allow production of iodine. A polyurethane film or foam dressing may be used, for example Tegaderm (3M Health Care) or Mepilex (Mölnlycke Health Care). This is a common requirement for hydrogel dressings.

The Iodozyme dressing releases approximately 5 times higher concentration of iodine than the Oxyzyme dressing and is intended for use with infected wounds (Wood et al. 2010).

Iodine in wound dressings provides an antimicrobial effect. Antimicrobial agents may reduce the colonisation of microbes on a non-infected wound, but there is little clear evidence of the effect of this on wound healing. If the wound is infected, action should be taken to treat the infection. This may include the use of antimicrobial agents (European Advisory Pressure Ulcer Panel 2009, European Wound Management Association 2008).

Hydrogels, such as those in the Oxyzyme and Iodozyme dressings, are designed to provide a moist environment and facilitate autolytic debridement of necrotic tissue. They may be able to absorb small amounts of exudate (British national formulary, 2014).

Intended use

Oxyzyme and Iodozyme dressings may be used on moderately exuding, non-exuding or dry wounds, and under compression therapy. The manufacturer states that the Oxyzyme dressing is intended for the treatment of non-infected or mildly infected wounds and the Iodozyme dressing may be used in the management of infected wounds.

Oxyzyme and Iodozyme dressings should not be used in people with a known or suspected sensitivity or allergy to iodide or iodine, or those with a thyroid disorder.

Setting and intended user

Oxyzyme and Iodozyme dressings are intended for use under the supervision of a healthcare professional, and may be used in any community or hospital care setting. They are applied by the same clinical staff who would normally change the patient's dressings. This would typically be a nurse, including district nurses and tissue viability nurses, but may also include other staff such as podiatrists. As with other treatments for more challenging wounds, and for -higher cost dressings, local supply arrangements are likely to need approval from a specialist such as a tissue viability nurse, or a wound clinic. The setting and staffing needs are similar to those for other wound dressings.

Current NHS options

Choosing the appropriate wound dressing is only part of providing effective wound care for patients with chronic wounds. It is also important to address the underlying causes of the original wound, ensuring patient well-being and quality of life. Additional strategies may include effective compression bandaging for venous leg ulcers, revascularisation, treating existing infection, pressure redistribution for pressure ulcers and adequate nutrition (European Wound Management Association 2008).

There are other wound dressings available (see costs and use of the technology section), with limited evidence to inform choices. The evidence is summarised in NICE key therapeutic topic wound care products, based on evidence in MeReC Bulletin Volume 21 Number 01.

NICE's guideline on diabetic foot problems recommends using the wound dressing with the lowest acquisition cost that is appropriate for the patient and the wound, because of the lack of robust evidence to differentiate dressings. NICE's guideline on pressure ulcers recommends that using a dressing that promotes a warm, moist wound healing environment is considered to treat grade 2, 3 and 4 pressure ulcers, following patient consultation. It recommends that iodine-based dressings are not used for neonates.

NICE's key therapeutic topic on wound care products also notes the importance of avoiding indiscriminate use of antimicrobial dressings because of concerns over bacterial resistance and toxicity. NICE's guideline on pressure ulcers also recommends against routine use of topical antiseptics or antimicrobials to treat a pressure ulcer. Topical antimicrobials should be considered where clinically indicated. Although there is little evidence of bacterial resistance to iodine developing, it may be possible, and the more frequently any antimicrobial is used the greater the possibility of resistance emerging (European Wound Management Association 2013).

The Scottish Intercollegiate Guidelines Network (SIGN) national clinical guideline (SIGN 120, Management of chronic venous leg ulcers, 2010) reviewed the available evidence on iodine-based dressings for the treatment of leg ulcers. It concluded that there was insufficient consistent evidence to make a recommendation about the use of these kinds of dressings.

NICE is not aware of other CE-marked devices that have a similar mode of action to the Oxyzyme and Iodozyme dressings. Alternative antimicrobial dressings are available using silver, honey or iodine.

Typical antimicrobial dressings

Typical hydrogel and hydrocolloid dressings

Dressings suitable as a covering layer for Oxyzyme and Iodozyme

There are many other dressings available at a range of costs.