Randy M. Gordon The skin is the largest organ of the body and functions as an excellent barrier against external injury. A burn can disturb this barrier function as a result of trauma from electrical, thermal, or chemical agents. Thermal burns constitute a large majority of these injuries.1 According to the American Burn Association, an estimated 486,000 burns are treated annually.1 This figure was compiled by combining data on visits to hospital emergency departments and outpatient clinics, freestanding urgent care centers, and private physician offices. Over 60% of the estimated U.S. acute hospitalizations related to burn injury involve patients who are admitted to 128 burn centers.1 Such centers now average over 200 annual admissions for burn injury and skin disorders requiring similar treatment. This percentage has increased steadily in recent decades as emergency care and transportation have improved. The most common burns occur in the home secondary to fire or flame and scalding or hot object contact; industrial accidents occur more often than electrical and chemical injuries.1 Statistically, males are more than twice as likely as females to sustain injury from burns, and Caucasians account for more injuries than patients of African-American, Hispanic, and other races combined. The temperature or heat content of the burning agent and the duration of exposure determine the extent of burn injury. A burn wound is best described by the zones of injury. Typically, three zones exist, with the innermost zone (zone of coagulation) representing the most damaged area. Cellular death and thrombosis of the blood vessels occur in this zone. The area of tissue adjacent to this zone is the zone of stasis, where blood flow is compromised. This zone may quickly progress to ischemia or may return to normal, depending on several factors related to resuscitation. The outermost zone is the zone of hyperemia. This zone has received minimum damage, is characterized by increased blood flow, and will fully recover.2 A burn wound is defined by the size and depth of the wound. The size of the burn is quantified by the percentage of the TBSA burned. This percentage can be estimated in several ways. A quick method assumes that the back of the patient’s hand is approximately 1% of the patient’s TBSA. Therefore, the percentage of TBSA burned is the number of “hands” equal to the size of the burn.3 The depth of a burn is measured by the skin layers injured, and nonprofessionals still refer to depth of injury as first, second, or third degree. Clinicians more commonly define burns by partial-thickness or full-thickness depth of injury. First-degree (superficial or partial-thickness) burns involve only the epidermis, which with the injury becomes glossy, red, and painful, such as a sunburn. Second-degree (partial-thickness) burns involve the dermis, which may present as dull or glossy with pink, red, or white pigmentation. The area may blister and be severely painful. Third-degree burns are full-thickness burns that extend to the subcutaneous fat. The area appears matte and may be white, brown, red, or black. The hallmark of the third-degree burn is that the burn site is insensate.4–5 The health care provider must obtain a full history of the mechanism of injury. The type of thermal or chemical exposure, the duration of exposure, and the time since the injury are important details. This history will help determine any risk for associated traumatic, pulmonary, or ocular injury. In assessing a patient with even a minor burn, any preexisting health condition is noted; some, such as diabetes or an immunocompromised status, affect the prognosis and disposition.6–7 The physical examination of the burn victim should be methodic and thorough. Initial general patient assessment should include evaluation for adequacy of airway, breathing, and circulation. The clinician should be alert for circumferential burns on a limb because the injury may compromise perfusion to the involved appendage. The depth, extent (percentage of TBSA burned), and location of the burn must be accurately determined and recorded. The examination should also include evaluation for any associated injuries.7 The skin is a significant protective physiologic barrier; infection and metabolic abnormalities can result when this barrier is disrupted. Simple thermal burns do not require diagnostic testing. For more serious injuries, a complete blood count (CBC), glucose, electrolytes, blood urea nitrogen (BUN), creatinine, and urinalysis may be necessary. Amino acid catabolism and fluid or protein loss through burn wound exudate may create increased metabolic needs and thus require laboratory evaluation for adequacy of hydration and protein stores.8 A chest x-ray study is indicated for a suspected inhalation injury. Wound sites with delayed healing may require cultures to determine if infection is a factor. If wounds are not healing, wound biopsy may also be indicated to facilitate detection of any underlying comorbidities or malignant neoplasms. In the case of a chemical burn, the local poison control center can assist in determining toxicity of and antidote for the chemical. If possible, the patient should provide the chemical container or a complete description of the substance to aid in identification.9
Burns (Minor)
Definition and Epidemiology
Immediate emergency department referral or specialist referral is indicated for burns that cause respiratory injury (inhalation or facial burns); burns of the hands, feet, genitals, or perianal area; full-thickness burns of more than 2% of the total body surface area (TBSA); minor burns of more than 10% TBSA in patients older than 50 years; or burns of more than 15% TBSA in patients 10 to 50 years of age.
Pathophysiology
Clinical Presentation
Physical Examination
Diagnostics
Burns (Minor)
Chapter 46
