Burning Issues

   Burns have three zones of injury: hyperemia, stasis and coagulation. The injured area most distant to the point of contact of the burn source is the zone of hyperemia. It has an appearance similar to a sunburn. The next-closest area to the burn source is referred to as the zone of stasis. In this area tissue damage and capillary permeability result in fluid leaking into the extravascular space. This can lead to edema and burn shock. The area closest to and including the point of contact with the burn source is the zone of coagulation. This zone involves necrosis and destruction of microcirculation that inhibit the effectiveness of the defense system. Zones of injury are dynamic. A zone of hyperemia may progress and become a zone of stasis if not treated appropriately. The provider's goal is to limit such progression of injury.^2,3,10,11

MORTALITY FACTORS

   The pathophysiology of burns, including SIRS, results in the all-too-common situation where burn victims survive the initial event, only to succumb to their injuries days or weeks later. Factors that must be considered when determining the prognosis of burn victims include the total body surface area (TBSA) involved, the patient's underlying health, the depth of the burn, toxic gas inhalation, degree of airway compromise, electrolyte imbalances, and the potential for the wounds to become infected. Providers are encouraged to thoroughly assess burn victims and anticipate the potential for complications. Underestimating or underreporting the severity of an initial situation may not support a positive outcome. Also, recognize that the burns visibly present on the patient's skin may only be part of the picture--internal burns and edema may be present as well. The patient who appears stable on scene can become critically unstable in a short period of time.^2,3,10,11

BURN TYPES

   There are several types of burns. Thermal burns are caused by contact with hot substances, like liquids, flames or solid objects. Electrical burns occur when electrical current flows through the body. Chemical burns involve liquid, solids or gases that are either acidic or alkaloid and result in tissue injury through chemical reactions. The following examples describe various types of burns/injuries that may be encountered in the prehospital setting.^2,3,10,11

THERMAL BURNS

   Scald injuries: Scald injuries are common among children between the ages of 6 months and 2 years. They are often caused by hot food or liquid spilled onto the skin. The most common cause is hot water. At 140°F water can cause a deep partial-thickness or full-thickness burn in less than three seconds. At 156°F, a deep scald burn can occur in one second. To put this into perspective, freshly brewed coffee has a temperature around 180°F.^2,3,7-10

   Scald injuries can involve both covered and exposed skin. Exposed skin tends to be burned less severely than clothed areas, because scalding clothing often remains in contact with the skin. Scald injuries can involve extremely high temperatures—substances such as cooking oil, grease, tar and asphalt can reach temperatures that exceed 400ºF.^2,3,7-10

   Scald injuries by immersion are also possible. These may occur when a victim, often a child or elderly adult, is dipped or plunged into hot water. This can result in deep and severe burns, because the hot liquid remains in contact with the skin for a greater period of time. Injuries may be seen on the heels, buttocks or genitalia/perineum.^2,3,7-10 In patients under 14, hair curlers, curling irons, room heaters, ovens and ranges, irons, gasoline and fireworks are common causes of fires resulting in thermal burns.^2,3,7-10

   Steam burns: These burns often produce extensive injuries from the high heat-carrying capacity of the steam and the release of pressurized steam and liquid. In addition to skin injuries, steam inhalation can also result in thermal injury to the respiratory system. Industrial accidents and opening hot car radiators are common causes of steam burns.^2,3,7-10

   Flame injuries: Flame injuries are the second-most common type of burn injury. Damage occurs when the heat from the flame causes proteins within the skin to denature. When the skin cools, it refolds into inelastic tissue. Common causes of fires that result in flame injuries include careless smoking, improper use of flammable liquids, motor vehicle collisions and ignition of clothing by stove and space heaters.

   Contact burns: Burns that involve the direct contact of skin with the source of the heat, such as metal, plastic, glass or hot coals, are referred to as contact burns. The size of the burn tends to be limited to the size of the surface contacted, but the burns can be deep and severe.^2,3,7-10

ELECTRICAL BURNS