All patients with severe burns should be hospitalized. The first priority in treating the burn victim is to ensure that the airway (breathing passages) remains open. Associated smoke inhalation injury is very common, particularly if the patient has been burned in a closed space, such as a room or building. Even patients burned in an open area may sustain smoke inhalation. Risk for smoke inhalation is greatest in victims who have injuries to the upper torso or burns of the face and in victims who cough up carbonaceous material or soot. If inhalation injury seems likely, an anesthesiologist or surgeon passes a tube through the patient’s nose or mouth into the trachea. This endotracheal tube allows the administration of high concentrations of oxygen and the use of a mechanical ventilator.
The next priority is to treat the associated burn shock. This requires the placement of intravenous lines through which resuscitating fluid can be administered; special lines are also placed into the circulation to monitor the resuscitation. A catheter is passed into the bladder to monitor urine output, another index of fluid resuscitation. Most burn centres treat the burn victim during the first 24 hours with intravenous administrations of a balanced salt solution (Ringer’s lactate); this solution replaces the fluids lost into the burn wound and from the burn wound into the environment. The administration of blood is not usually necessary, because in most burns blood loss is minimal, and less than 10 percent of the blood suffers hemolysis (i.e., the destruction of red blood cells). This hemolysis of blood, however, can cause serious secondary injuries, particularly to the kidneys; if severe enough, it may even cause the kidneys to fail. This danger can be minimized by rapidly establishing fluid resuscitation and by stimulating urine output with diuretics such as mannitol. A careful medical history is taken, and tetanus toxoid is administered.
After this initial treatment of the airway and resuscitation of the burn shock, a decision must be made as to the disposition of the patient. If the patient is admitted to a burn centre, he is usually placed into a special tub, where the wound is cleansed with mild soap solutions. The wound is then dressed. Derivatives of sulfa—particularly mafenide—and other antibiotics are now used with great success in preventing the infection of burn wounds and the subsequent spread of bacteria and toxins through the bloodstream and tissues (sepsis).
Almost immediately there are other problems that the burn surgeon must address. The patient’s ongoing fluid balance must be monitored and regulated, his nutritional needs must be met, pain must be controlled, and the burn wound itself must be repaired. Pain is most problematic in patients with partial or deep second-degree burns and is aggravated by the necessity of frequent dressing changes and physical therapy. In addition, pain leads to increased catecholamine release, which aggravates the patient’s nutritional needs and energy expenditure. Burn centres have employed innovative measures to control pain, including the use of morphine intravenously, the administration of incomplete anesthetic drugs at the time of dressing changes, and even the use of general anesthesia during major debridements.
Nutrition can be a particularly vexing problem because the caloric needs are often greater than the patient can consume in a normal fashion. Thus, supplementary feedings administered intravenously or through a feeding tube placed into the stomach are commonplace in treating severe burns. One of the major advances in the treatment of the critically burned has been the use of hyperalimentation, a procedure in which total nutritional support can be provided through a catheter placed into a large central vein.
The goals in managing the burn lesion are to prevent infection, to avoid further injury to the damaged tissues, and to close the wound as soon as possible. There are three major methods of therapy for the burn wound: exposure, occlusive dressings, and primary excision.
Exposure therapy is indicated for surfaces that are easily left exposed, such as the face. The burn is initially cleansed and then allowed to dry. A second-degree burn forms a crust, which falls off after two or three weeks, revealing minimally scarred skin beneath. Full-thickness burns will not form a crust because of the overlying dead skin, or eschar. The goal of exposure therapy is to soften the eschar and remove it. Exposure allows the eschar to dry. After it dries, saline-soaked gauzes are applied to the eschar to soften it and hasten its spontaneous separation from the underlying tissues. The advantage of exposure therapy is that the patient is not immobilized in bulky dressings. It is particularly useful in burns that cover less than 20 percent of the body area. The chief disadvantage is that the protection against infection afforded by sterile dressings is absent. In addition, pain and heat loss are greater in exposed wounds. Exposure therapy is usually combined with the use of antibacterial creams.
Occlusive dressings, usually combined with topical antibacterial agents, are more commonly used in the treatment of extensive burns. The antibacterial ointment or cream may be applied to the patient or to the gauze. The use of occlusive dressings provides a sterile barrier against airborne infection; the dressings also help minimize heat loss and pain. On the other hand, the bandages must be absorptive as well as occlusive and thus are usually bulky and restrictive. Furthermore, the dressings must be changed as often as every eight hours to prevent the growth of bacteria in the warm, moist environment of the covered wound. As pointed out previously, these frequent dressing changes may increase the amount of pain and need for anesthetics.
In both of the above methods of wound treatment, the patient is usually immersed daily in a special tank, where remaining dressings and creams are washed off and loose tissue is debrided. The patient is encouraged to move about to reduce scar formation and subsequent disabling contractures (permanent contractions of scar, muscles, and tendons) over the joints.
Primary excision—that is, the surgical removal of necrotic tissues within 24 to 48 hours of the injury—is used to prepare full-thickness burns for grafting at the earliest possible time. After the dead skin has been removed, the surgeon’s primary goal is to cover the burned area as rapidly as possible with autografts—that is, grafts of the patient’s own skin harvested from uninjured areas of the body. Often, there is a discrepancy between the amount of harvestable skin and the extent of the potential recipient sites. This discrepancy can be addressed by covering the debrided or excised areas with allografts of skin obtained from cadavers, or by treating the burn with porcine xenografts (pigskin), antibiotic solutions, or special plastic dressings. These measures are only temporary, however, and skin autografting is the final method of coverage for most full-thickness injuries. Most autografts use split-thickness skin (i.e., thin slices of skin including the epidermis and part of the dermis), which the surgeon obtains from unburned areas using an instrument called a dermatome. The face, neck, and surfaces around joints receive first priority for grafting. Grafts are usually dressed and inspected frequently to be sure they are taking.