A majority of burns result from exposure to high temperatures, which injures the skin. Thermal skin injury may be caused by flame, scalding, or direct contact with a hot object. Similar destruction of skin can result from contact with chemicals such as acid or alkali or contact with an electrical current.
Intact skin provides protection against the environment for all underlying tissue and organs. It aids in heat regulation, prevents water loss, and is the barrier against bacterial invasion. Burns can be minor or can present a life-threatening emergency, depending on the heat's intensity, the total area of tissues burned, and the length of exposure to the skin.
Burns are generally classified according to the depth, extent of injury and the severity of skin tissue damage.
• First-degree burns (superficial partial thickness) affect only the outer layer of the skin (epidermis), causing pain and redness
• Second-degree burns (partial thickness) extend to the second layer of the skin (the dermis), causing pain, redness, and blisters that may ooze
• Third-degree burns (full thickness) involve both layers of the skin and may also damage the underlying structure such as bones, muscles, and tendons. The burn site often appears pale, charred, or leathery. There is generally no pain in the area because the nerve endings are destroyed.
Regardless of the type of burn, once a break in the skin, and the risk of infection exists both at the site of the injury and potentially throughout the body. In severe or widespread burns, fluid is lost through the skin, and the person can become dehydrated and can lead to life-threatening.
Treatment of burns depend on the severity, extend and the depth of burns:
First degree or superficial partial burns heal by regeneration of skin from dermal elements that remain intact. Dressings are necessary to reduce infection and adsorb exudate.
Second degree or partial-thickness burns involving the deeper reticular dermis and third degree or full thickness burns may require debridement of necrotic tissue and skin grafting. Skin grafting provides an effective way to cover a wound commonly in burns wound. The skin can be from another part of the body (the donor site) and detached from its blood supply and placed in the recipient site, where it develops a new blood supply from the base of the wound. Colour match, contour and durability of the graft are all considerations in selection of an appropriate donor area.
Split-thickness (or partial thickness) skin graft contains epidermis and a portion of the dermis of the donor site The graft is usually taken from an area that is ordinarily hidden by clothes, such as the buttock or inner thigh. Gentle pressure from a well-padded dressing is then applied, or a few small sutures used to hold the graft in place. A sterile nonadherent dressing is then applied to the raw donor area for approximately three to five days to protect it from infection.
Full-thickness skin graft involves both layers of the skin – the epidermis and dermis. The process for a full-thickness graft is more complicated than partial-thickness grafts. The advantage of full thickness graft are- provide better contour, more natural color, less contraction at the grafted site and has a greater ability to withstand trauma, can add tissue where there has been a loss or padding is required. Cosmetically, the outcome is usually better. The donor site is then closed primarily with sutures leaving a minimal defect. The recipient site – once the graft is in place, it will be fastened to the surrounding tissues with sutures or staples.
What to expect during the recovery phase?
Quick recovery is expected after split-thickness skin grafting. The skin graft must be well protected. New blood vessels begin to grow from the recipient site into the transplanted skin within 36 hours. Most skin grafts are successful, but in some cases they do not heal well and require repeat grafting. The graft should also be monitored for good circulation and its colour. Exercise that might stretch or injure the graft should be avoided.
Full-thickness grafts need a longer recovery period. Most people with these grafts need to stay in the hospital for few days.
Risks & Complications of Skin Grafts
Risks and potential complications of skin grafts include:
• rejection/loss/death of the graft
• unsatisfactory aesthetic results, such as scarring, skin texture irregularities or discoloration
• loss or reduction in skin sensation
• increased sensitivity; chronic pain (rarely)
• anaesthesia risks