What are the different types of burn injuries?
In this first aid blog post we discuss burn injuries and the different classifications of burns.
A large proportion of burn injuries, both minor and serious, occur in the home, where 80 per cent of the victims are children in the 1 to 14 age group. Other categories of concern in the home are the elderly and disabled while in industry, electricians and workers in the chemical, refinery and catering industries.
Cooling the burn wound can have positive effects for the patient as it acts to stop the burning process and halt burn injury progression, it is a good analgesic and it also affects the immune response to burn injury. There is a risk, however, of hypothermia, particularly in children and many patients are cooled to excess outside hospital.
According to some published articles, burn size estimation is very difficult and should make no difference to patient care and so should be removed from first aid teaching. A useful guide as to the extent of the burn injury is to compare the area of the burn against the size of the patient’s extended hand, this equals to approximately one per cent of the total body surface area.
Burns in the region of ten per cent of the body area are serious and may produce severe shock. For assessment purposes the area burnt is more significant than the depth of the burn. In addition, on average burned children become shocked more quickly than adults.
Blisters are an indication that the body is not happy with the heat it has absorbed. If the blisters rise immediately it is almost certainly that the burns are partial thickness and if they take longer to appear, for example one or two hours or more, the burns are more than likely to be superficial. All blisters should ideally be seen by a doctor and not burst.
Airway management needs to be one of the prime concerns with any patient with facial or neck burns or those who have a severe inhalation injury. With any localised burn to the face there will be an amount of swelling that ensues and this can occlude the airway.
The classification of burns
With burn injuries there are five heat categories: thermal, chemical, mechanical, electrical and radiation.
Thermal: This source is divided into two categories, dry thermal and wet thermal injuries. Dry thermal will involve flames, very hot objects, and radiant heat. Wet thermal will involve steam and hot liquids (Steam has the capacity to carry 4000 times more heat than dry air). Inhalation of hot smoke or gases will cause the airways to swell and could result in a compromised airway.
When managing dry thermal injuries burnt clothing, and foreign objects adhering to the burn location must not be removed. The body’s defence mechanism will start to send fluids to the site, causing oedema, if there is a concern that constrictive clothing, jewellery or footwear will prevent circula- tion to and beyond the location, remove the constricting item.
Wet thermal injuries are caused by hot liquids such as boiling water, coffee, tea, soup, chip pan oil, tar, molten liquids. If clothing is saturated it will have to be cooled (to protect the rescuer) and carefully removed, otherwise it will continue to act as a heat source. If possible try not to burst underlying blisters. With an exposed scald injury immediate cooling can be started.
Chemical: The source for this category is all chemicals both wet and dry, alkalis and hydrocarbons and phenols (industrial cleaners, solvents, degreasing agents, petrol). Chemical burns are not usually thermic, but are caused by tissue reaction to noxious substances, the amount of tissue damage will depend on the chemical and exposure time. Full irrigation of all liquid chemical burn sites must take place prior to cooling, large amounts of flowing water will be required to wash away and break down the liquid chemical or chemicals in question. It is worth considering using warm water for irrigation as this will help to protect the core temperature of the patient. If possible, remove all saturated clothing, footwear, watches and jewellery from the patient.
Mechanical: The main source of a mechanical burn will be surface friction, for example carpet burns, plastic playing pitches, rope burns and motor vehicle collisions involving motorcyclists. Mechanical burns will always occur where the skin is in contact with a surface moving quickly in the opposite direction.
Electrical: Patients in this category will usually have been in contact with one of the following two sources of electricity: alternating current (AC) or direct current (DC). Electrical injuries can be classified into three groups: true electrical injury, arc burn and electrical thermal burn. True electrical injury occurs when electricity passes through the body after contact with an electrical conductor. This burn will present the classic entry and exit wounds, along with deep tissue destruction. With an arc burn, the victim is not in actual contact with electricity. These injuries are most common with high tension current. There may be an entry and exit wound. Usually there are scattered spots of injury where the current made momentary contact as it jumped to ground.
Cardiac complications should always be considered when called to an electrical burn injury, on arrival make sure that the power supply is disconnected at the mains before approaching the patient having ensured that the scene is safe.
Radiation: In Europe one of our primary source of radiation concern is the sun. In the case of serious sunburn, where any blisters are present medical intervention is advised.
Cold Burns: These burns come under a different management criteria and do not require cooling. Water Jel or any other cooling method should not be used for the management of any cold burns.
The depth of burns can be categorised as:
Superficial: These burns involve only the epidermis, the colour of which may vary from pink to red. They usually heal within three to six days and can be quite painful. The outer layer of skin may peel away and reveal new healed skin underneath with no residual scarring. A common example of superficial burns is sunburn.
Partial Thickness: This category can be divided into two sections – superficial partial thickness and deep partial thickness burns. Superficial partial thickness burns involve the epidermis and dermis, it will often be bright red, blistered and painful. These burns can take up to 21 days to heal usually with no scarring. Deep partial thickness burns will include all of the epi- dermis, and deep into the dermis, the site of insult may be dry or wet, and capillary refill will be reduced, sensation to pressure remains intact, and the site is less painful. These burns take a long time to heal and may result in scarring if not excised and grafted.
Full Thickness: These burns will involve all layers of the skin, and possibly subcutaneous fat, muscle, and bone. They may appear as charred, waxy, mottled, leathery, pale and dry, and will be firm to the touch. These burns are in a semi-anaesthetised state and will not be sensitive to pain and light touch, they will require advanced medical intervention and hospitalisation.
First aid treatment for burns
Assessment of patients with burns injury should include:
Assess ABCDs. Specifically the airway for signs of burns which include:
– soot in the nasal and mouth cavities;
– cough and hoarseness;
– coughing up blackened sputum;
– difficulty in breathing and swallowing;
– blistering around the mouth and tongue;
– scorched hair, eyebrows and facial hair.
Assess breathing for rate, depth and breathing difficulty
Cool the burn for a minimum of 10 minutes. After initial cooling, cover the burn area, ideally with cling film (unless chemical burns) and continue to irrigate or cool over the cling film while ensuring the rest of the patient is warmly wrapped.
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