include availability, collection, storage, transmission of infection and cost [22].

Other dressings

Conventional dressings such as Vaseline gauze or silicone sheets (Mepitel ) can be used to cover the wound while re-epithelialization takes place. After application, these dressings need frequent changes, which can be painful. These types of dressing are useful for small burns (less than 5% TBSA). Synthetic dressingssuchasDuoderm ,Omniderm Tegaderm and hydrocolloids have all been used with success to dress such wounds. However a recent Cochrane review recently highlighted the paucity of high quality Randomised Controlled Trials on dressings for superficial and partial thickness burn injury. The authors summarised that available evidence was of limited usefulness in aiding clinicians to choosing suitable treatments [23].

Exposure

After cleaning and debridement, wounds are left open in a warm dry environment o crust over. The coagulum formed separates as re-epithelialization proceed underneath. Advantages of this method are comfort and no need for dressing changes. Disadvantages of this method include prolonged inpatient treatment, specialized ward and nursing requirements and higher infection rates. This technique is now not commonly used apart from the treatment of specialized areas such as the face, genitalia and perineum.

Large partial thickness wounds

In large superficial partial thickness injury ( > 40% TBSA) there is a higher risk of wound contamination, infection and subsequent organ dysfunction and morbidity.

The use of allograft applied within 24 hours of the injury is thought to improve outcome [24]. Under anaesthesia the wound is cleaned and all blisters and non adherent epidermis removed. Allograft split skin grafts meshed 2:1 are placed over the open dermal wound and secured with staples. It is important not to open up the mesh on the allograft as this can

lead to desiccation, infection and deepening of the underlying wound. A standard graft dressing is applied. A mid-dermal burn injury can be debrided with a dermatome at a depth of 10–15/1000 inch and allograft applied. This wound should then go on to heal spontaneously with the allograft spontaneously separation as the wound epithelialises. There should not be incorporation of the allograft into the wound unless the wound is deeper.

Xenograft skin can be used in a similar fashion to the allograft [25], but does not usually adhere as well, leaving the wound open to desiccation, infection with associated pain.

Biobrane can be used in the same way as for smaller injuries. There is a higher rate of wound infection which can lead to loss of the Biobrane and deepening of the burn wound.

Topical antimicrobials such as silver sulfadiazine or Acticoat can be used for this type of wound in a similar manner to that described above. It is the treatment of choice for wounds that present late and are colonized, as by definition the wounds should heal spontaneously. The dressing changes can be painful and are an ordeal for the patient. There is a high incidence of wound sepsis, which can lead to deepening of the burn wound, which may then necessitate skin grafting.

Deep partial thickness wound

Deep partial thickness burns are associated with significant morbidity in terms of time to healing, infective complications and subsequent scarring. Conservative management leading to spontaneous healing usually involves prolonged and painful dressing changes and the resultant scar is invariably hypertrophic leading to cosmetic and functional disfigurement and disability. An early surgical approach that tries to preserve dermis and achieve prompt wound healing is usually the optimal treatment method.

Total wound excision

Burns that are deemed to be deep partial thickness in nature are best tangentially excised and the wound covered with autologous split skin grafts [26]. The grafts usually require meshing and the amount of