Annually 175,000 people present to Emergency departments with burn injuries, of which 13,000 require hospital admission1. There are various types of burn injuries, these include:
- Flame Burns
- Contact Burns
- Electrical Burns
- Chemical Burns
- Cold injuries
- Friction Burns
Scald injuries are the most frequent cause of burn in the UK, particularly in children2.
Patients with burn injuries should be assessed and treated following ATLS/EMSB ABCDE principles. Patients with facial, intra-oral burns or those who have sustained an inhalation injury are susceptible to airway compromise. It is imperative that an anaesthetist assesses the patient’s airway.
Large burn injuries require fluid resuscitation due to fluid shifts from the intravascular compartment to burned and non-burned surrounding tissues. Additionally patients are susceptible to hypothermia and their core temperature must be maintained.
A burn wound should be examined to determine the size and depth of the injury.
Depth of injury is determined by understanding the anatomy of the skin and the pathophysiology of a burn wound. Superficial burns / erythema, is an injury solely to the epidermis. Skin integrity is therefore not breached and therefore this does not result in a wound. Its clinical features include erythema and pain. Superficial partial thickness burns represent burns to the papillary dermis and is characterised by blistering. In deep dermal burns, injury to the reticular dermis results in a mottled appearance with fixed staining of coagulated capillary blood vessels, a loss of sensation (due to damage to sensory nerve fibres) and a loss of hair following injury to the hair root. A full thickness burn has a brown, leather appearance that is insensate and does not blanch. It represents injury to the epidermis, dermis and subcutaneous tissue.
The size of the burn wound is measured according to % Total Body Surface Area (%TBSA). Various methods to accurately determine %TBSA includes:
- Comparing the burn size to the size of the patient’s palm (including fingers) (which is approximately 1%)
- Applying Wallace’s Rules of Nines
- Using a Lund and Browder chart to measure burn size
- A proprietary app for charting burns
%TBSA should be determined once all the burns blistering has been de-roofed.
Superficial partial thickness burns can be treated conservatively with dressings as they are likely to heal in 10-14 days. Mid-dermal (burns deep within the papillary dermis) may take up to 21 days to heal. These wounds heal due to the survival of epidermal appendages within the dermis that enables epithelialisation from both the wound bed and from the sides of the wound. Larger or mid-dermal burns are often dressed with biological dressings to encourage healing.
Key objectives/procedure summary
- How to safely set up and use a Watson knife to tangentially excise a burn wound and to harvest a split thickness skin graft.
- How to prepare the harvested skin graft for application to a wound.
- How to apply a skin graft and secure it to the recipient site.
There is good evidence that if a burn wound takes longer than 21 days to heal, then there is an increased risk of hypertrophic scarring. This is due to the loss of epidermal appendages, deep dermal/ full thickness burns heal from just the edges of the wound 3, 4. The wound can take up to 6-8 weeks or longer to heal. These burns are at a high risk of developing hypertrophic scarring and secondary joint contracture. Depending on the size, site of the burn and patient co-morbidity factors, the burn wound should ideally be excised early and a skin graft applied to the wound bed to facilitate the speed of the wound healing. Conservative methods of treatment include the use of anti-bacterial, silver-based dressings to limit infection, whilst the burns heal by secondary intention. These methods are used if the patient is not suitable for surgery, however it is likely that such wounds will have poor functional and aesthetic outcomes.
Other factors that may delay wound-healing include: infection, over-granulation and patient factors (steroid use, diabetes, immunosupression, peripheral vascular disease).
In large burns, early excision and grafting attenuates the Systemic Inflammatory Response Syndrome (SIRS), the hypermetabolic response, the risk of multi-organ failure, sepsis and surgical blood loss. Additionally, early skin graft harvest and application is cost-effective, reduces length of hospital stay, facilitates the return of function and return to work. Skin grafts can be used as a sheet or be meshed to allow fluid egress and to expand the area covered.
- Caution in pregnancy
- Bleeding (if the patient requires warfarin)
- Co-morbidities affecting the use of general anaesthesia
Excision of a small non-healing burn wound can be performed under local or general anaesthesia. The choice is dependent on the size of the burn wound to be excised and the size of the donor area required for skin graft harvesting. A small burn can be surgically managed using local anaesthesia in an adult, however this would not be appropriate in paediatric cases. Additionally, the option of general anaesthesia is dependent on the patient’s co-morbidities and the choice of the patient. Regional or spinal anaesthesia as well as local anaesthetic blocks are also options.
Blood loss is a complication in large burns. Blood loss is difficult to assess and methods used to reduce blood loss include the use of a tourniquet, infiltration of adrenaline to the wound, the use of adrenaline soaked gauze and methods to maintain core body temperature.
The length of post-operative stay following surgery is dependent on many factors which include the patient’s medical co-morbidities, the site of surgery, the need for splinting, the type of dressings used and the proposed plan for dressing changes. Dressings should be non-adherent to allow easy removal, avoid graft shear, be easy to secure and comfortable. Excision of small burn wounds and application of a split thickness skin graft can be performed as a day-case procedure. This is as long as the skin graft can be adequately secured by the use of dressings or casts which also do not impair the patient from safely managing at home.
Common: Bleeding, scarring (Hypertrophic, Keloid) of donor and recipient site, joint contracture, skin graft failure secondary to: Infection, seroma, haematoma or shear. Change in pigmentation to the donor and recipient site, contour deformity of the burn wound and decreased sensation.
- Lawrence J.C., Lilly H.A.I. (1999), ‘Burns: UK epidemiology, microbiology and infection control’, Chapter 9 in ‘Trauma: A Scientific Basis for Care’, Alpar E.K., Gosling P. (Ed) Arnold Publishing.
- Stylianou N, Buchan I, Dunn KW. A review of the internation Burn Injury Databse (iBID) FOR England and Wales: Descriptive Analysis of Burn Injuries 2003-2011. BMJ Open 2015; 5.
- Cubison TC, Pape SA, Parkhouse N. Evidence for the link between healing time and the development of hypertrophic scars (HTS) in paediatric burns due to scald injury. Burns 2006; 32(8): 992-9.
- Deitch EA, Wheelahan TM, Rose MP, Clothier J, Cotter J. Hypertrophic burn scars: analysis of variables. J Trauma 1983; 23(10): 895-8.