Emergency medicine - Managing burns and scalds

Cool the burn for 20 minutes but warm the patient as a whole, explains Dr Clare Hammell.

Burn on a patient's back caused by a hot water bottle (Photograph: SPL)
Burn on a patient's back caused by a hot water bottle (Photograph: SPL)

Burn injuries are common - around 175,000 people attend UK emergency departments each year with such injuries.1

Despite this, there may be uncertainty among doctors who do not regularly see such injuries about their initial management.

Burn injuries are usually thermal in nature but may also result from chemical injury. Thermal burns are classified by the amount of skin loss. Full thickness burns extend into the subcutaneous tissues. Partial thickness burns can be categorised into superficial (epidermis only), superficial dermal (extending into the upper layers of the dermis) and deep dermal (extending into the deeper layers but not through the dermis).

Where a fire is concerned, rescuer safety and extinguishing the fire should be the initial priorities. Occasionally patient assessment and management will have to wait until the scene of the incident is declared safe by the fire and rescue service.

Burn features

Superficial
Red and moist, blanches with pressure and quickly regains colour.

Superficial dermal
Paler and dry, blanches with pressure and slowly regains colour.

Deep dermal
Mottled red colour, non-blanching.

Full thickness
Pale, leathery/waxy and hard.

Assessment of the burned patient
Major burns are those covering 25 per cent of total body surface area but any burns greater than 10 per cent should be treated as such.

Assessment of burn area is often performed badly with small burn areas being overestimated and large burn areas being underestimated.2 For small or very large burn surface areas, estimation by approximating the patient's palm to one per cent of their body surface area can be made.

In adults, the 'rule of nines' is also used, whereby the body is divided into surface areas of multiples of 9 per cent (for exa-mple, arm 9 per cent, whole leg 18 per cent). This method is not suitable for children. In both methods, areas of simple erythema are not included in area estimation.

Lengthy assessment of burn depth is not required prior to hospital transfer as it will not alter management and may delay on-scene time.

Cooling the burn
Immediate cooling of a burn wound has been shown to red-uce the depth of the injury. The Australian and New Zealand Burn Foundation recommend immediate cooling of contact burn injuries for a period of 20 minutes with cold running tap water (approximately 15 degrees celsius).

Delayed cooling instituted up to three hours after the burn injury has also been shown to be successful in reducing depth of burn assessed at 24 hours and one week post injury.3 Ice should not be used to cool burns as the subsequent re-epithelisation of the wound and scar appearance are compromised.

Warming the patient
Evaporative heat loss is greatly increased following a major burn injury and despite cooling the burnt area, attempts to warm the patient as a whole should be made. Expose only small areas of skin sequentially in a warm environment when assessing burn size. Cool the burn and warm the patient.

Covering the burn
The burnt area should be covered loosely with a cellophane-type material, such as cling film.

This helps to keep the area clean, reduce heat and evaporative losses and also reduce pain from exposed dermal nerve endings. Avoid wrapping the cellophane too tightly as this can cause vascular compromise, particularly with the administration of IV fluids and the res-ulting oedema formation at the site of injury.

Airway assessment
Inhalational injury may result from fires in enclosed spaces. Approximately 20-30 per cent of patients with major burns have a coexisting inhalational injury.

Features of inhalational injury
  • Fire within an enclosed space.
  • Facial burns.
  • Singed nasal hair/eyebrows.
  • Carbonaceous deposits within oropharynx.
  • Hoarse voice.

Such injuries can immedia-tely affect airway patency but often take up to six hours to manifest causing a severely oedematous airway which makes subsequent airway management hazardous. See box (right) for the signs associated with inhalational injuries.

Patients exhibiting any of these signs require immediate transfer to secondary care along with administration of high-flow oxygen via a facemask.

Circulatory management
IV fluid replacement is a cornerstone of management of burn injuries.

For patients with total burn surface area more than 25 per cent or with a transport time to hospital of more than one hour, IV fluids should be commenced prior to hospital transfer. Crystalloids such as Hartmann's solution and 0.9% sodium chloride are suitable.

Resuscitation formulas to calculate the estimated volume of fluid required have been developed but it must be remembered that these provide an estimate only. It is also impractical to perform such calculations in the pre-hospital environment.

An approximate guide to how much fluid to give en route to secondary care is described below:

  • Adults - 1,000ml.
  • Children (10-15) - 500ml.
  • Children (five-10) - 250ml.

Analgesia
Burn injuries are painful and analgesia is a priority. IV opiates, such as morphine and an antiemetic, will usually be req-uired. An initial bolus of 50-100 microgram/kg should be given and titrated to effect.

Chemical burns
Strong acids and alkalines can cause dermal burns. Common industrial acids in use are sulphuric, hydrochloric, hydrofluoric and phosphoric acids.

Prompt (within 10 minutes) and thorough irrigation of the wound will limit its depth.

Obtain as much information from the scene about the chemical, its strength and the volume and duration of the exposure.

  • Dr Hammell is a specialist registrar in anaesthesia and intensive care medicine, Royal Liverpool University Hospital, Liverpool

References
1. Hettiaratchey S, Dziewulski P. ABC of Burns. BMJ 2004; 328: 1366-8.

2. Collins N, Smith G, Fenton OM. Accuracy of burn size estimation and subsequent fluid resuscitation prior to arrival at the Yorkshire Regional Burns Unit. A three-year retrospective study. Burns 1999; 25(4): 345-51.

3. Rajan V, Bartlett N, Harvey J et al. Delayed cooling of an acute scald contact burn injury in a porcine model: Is it worthwhile? J Burn Care Res 2009; 30(4): 729-34.

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