Damage caused to the body by contact with flames, hot substances, some chemicals, radiation (including sunlight), or electricity. Burns are classified by depth of skin damage and by percentage of skin damaged. First-degree burns injure only the epidermis (top layer), with redness, pain, and minimal edema. In a second-degree burn, damage extends into the dermis (inner layer), with redness and blisters. Third-degree burns destroy the entire thickness of the skin. There is no pain, because the skin's pain receptors are destroyed. Burns deeper than the skin can release toxic materials into the bloodstream and may require amputation. Secondary shock follows severe burns, caused by loss of fluid both in the destroyed tissue and in leaks from the damaged area. Treatment depends on severity; first-degree burns need only first aid; third-degree burns require long-term hospitalization. Depending on the type, extent, and site of the burn, it may be left exposed, covered with a bandage, or excised to remove dead tissue in preparation for skin grafts. Complications of burns include respiratory problems, infection, ulcers in the stomach or duodenum, and, especially in brown skin, thick scarring. Seizures and hypertension after burns occur almost entirely in children. Survivors usually require plastic surgery, long-term physical therapy, and psychotherapy.
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Table 1. A description of the traditional and current classifications of burns.
|Nomenclature||Traditional nomenclature||Depth||Clinical findings|
|Superficial thickness||First-degree||Epidermis involvement||Erythema, minor pain, lack of blisters|
|Partial thickness — superficial||Second-degree||Superficial (papillary) dermis||Blisters, clear fluid, and pain|
|Partial thickness — deep||Second-degree||Deep (reticular) dermis||Whiter appearance, with decreased pain. Difficult to distinguish from full thickness|
|Full thickness||Third- or fourth-degree||Dermis and underlying tissue and possibly fascia, bone, or muscle||Hard, leather-like eschar, purple fluid, no sensation (insensate)|
Burns can also be assessed in terms of total body surface area (TBSA), which is the percentage affected by partial thickness or full thickness burns (superficial thickness burns are not counted). The rule of nines is used as a quick and useful way to estimate the affected TBSA.
Most chemicals that cause severe chemical burns are strong acids or bases. Chemical burns are usually caused by caustic chemical compounds, such as sodium hydroxide, silver nitrate, and more serious compounds (such as sulfuric acid and Nitric acid). Hydrofluoric acid can cause damage down to the bone and its burns are sometimes not immediately evident.
Electrical burns are caused by an exogenous electric shock. Common causes of electrical burns include workplace injuries or being defibrillated or cardioverted without a conductive gel. Lightning is a rare cause of electrical burns. The internal injuries sustained may be disproportionate to the size of the burns seen, and the extent of the damage is not always obvious. Such injuries may lead to cardiac arrhythmias, cardiac arrest, and unexpected falls with resultant fractures.
Radiation burns are caused by protracted exposure to UV light (as from the sun), tanning booths, radiation therapy (as patients who are undergoing cancer therapy), sunlamps, and X-rays. By far the most common burn associated with radiation is sun exposure, specifically two wavelengths of light UVA, and UVB, the latter being more dangerous. Tanning booths also emit these wavelengths and may cause similar damage to the skin such as irritation, redness, swelling, and inflammation. More severe cases of sun burn result in what is known as sun poisoning.
Scalding is caused by hot liquids or gases, most commonly occurring in the home from exposure to high temperature tap water. Steam is a common gas that causes scalds. The injury is usually regional and usually does not cause death. More damage can be caused if hot liquids enter an orifice. However, deaths have occurred in more unusual circumstances, such as when people have accidentally broken a steam pipe. The demographics that are of the highest risk to suffering from scalding are young children, with their delicate skin, and the elderly over 65 years of age.
A cold burn (compare frostbite) is a kind of burn which arises when the skin is in contact with a low-temperature body. They can be caused by prolonged contact with moderately cold bodies (snow and cold air for instance) or brief contact with very cold bodies such as dry ice, liquid helium, liquid nitrogen, liquid discharged from an upside-down gas duster, or other refrigerants. In such a case, the heat transfers from the skin and organs to the external cold body.
If the patient was involved in a fire accident, then it must be assumed that he or she has sustained inhalation injury until proven otherwise, and treatment should be managed accordingly. At this stage of management, it is also critical to assess the airway status. Any hint of burn injury to the lungs (e.g. through smoke inhalation) is considered a medical emergency.
To help ease the suffering of a burn victim, they may be placed in a special burn recovery bed which evenly distributes body weight and helps to prevent painful pressure points and bed sores. Survival and outcome of severe burn injuries is remarkably improved if the patient is treated in a specialized burn center/unit rather than a hospital. Serious burns, especially if they cover large areas of the body, can result in death.
Once the burning process has been stopped, the patient should be volume resuscitated according to the Parkland formula, since such injuries can disturb a person's osmotic balance. This formula dictates the amount of Lactated Ringer's solution to deliver in the first twenty four hours after time of injury. This formula excludes first and most second degree burns. Half of the fluid should be given in the first eight hours post injury and the rest in the subsequent sixteen hours. The formula is a guide only and infusions must be tailored to the urine output and central venous pressure. Inadequate fluid resuscitation causes renal failure and death. Adequate pain management, including administration of opioid analgesics (such as morphine or hydromorphone, for example) and sometimes other medication (e.g. ketamine, tranquilizers or general anesthetics) are also essential in all stages of treatment of severe burns, as this helps to prevent the progression of shock and alleviates the severe distress from the trauma.
Hyperbaric oxygenation has been shown to be a useful adjunct to traditional treatments.