As in cases of other forms of injury, there is expected development of soft tissue edema near burn injuries. However, larger burns (in excess of 20% total body surface area), edema of soft tissue remote to the burn commonly develops as well. If the edema develops under normal skin or skin with a superficial injury, the skin will stretch and allow for a change in volume of the underlying tissue. However, when the skin suffers a full-thickness burn (eschar), the desiccated tissue loses its elasticity. The inelasticity of the overlying burned skin, when it is circumferential on an extremity, can cause these tissue pressures to exceed normal perfusion pressures, thereby compromising blood flow to the extremity. On the trunk, a full-thickness circumferential burn can compromise respiratory mechanics, creating an extrinsic restriction of ventilation. Escharotomies are performed to relieve the restriction imposed by the layer of necrotic, inelastic skin.
By definition, the performance of an escharotomy mandates the presence of eschar, and typically, it will be nearly circumferential. Second, patients will be symptomatic. The cardiovascular embarrassment caused by circumferential eschar of the torso is analogous to that seen with other restrictive lung defects. Typically, patients with massive burns will be mechanically ventilated. They will show evidence of increasing inspiratory pressures with diminishing tidal volumes followed by escalating hypercarbia. Hypoxia will be a late change. For burned extremities, the course is analogous to other causes of compartment syndrome. There may or may not be a change in peripheral pulses, and swollen extremities may feel “more tense.” It cannot be overemphasized that neither provides reassurance and can only heighten concern. For conscious patients, neuromuscular examination is most appropriate—looking for neuromuscular changes associated with ischemia (the five P’s: pain, pallor, paresthesia, pulselessness, and paralysis). For ambiguous cases, the gold standard is to measure the compartment pressures. It is also worth mentioning that some surgeons will complete escharotomies in an empirical fashion, and it is worth noting that it is still essential to monitor for development of compartment syndromes.
Attention should be paid to the hemodynamic stability of the patient, as well as close fluid and electrolyte management in burn patients. Preoperative antibiotics are essential to prevent infection.
Because all cutaneous nerves have been destroyed in the area of full-thickness burns, the pain is much less than one might anticipate, and no anesthetic is required prior to performing an escharotomy. However, sedation may be helpful because the use of electrocautery may cause mild pain.
The skin is prepped with an antiseptic solution and sterile drapes applied. Then a time-out is performed.
A map for performing escharotomy is shown in FIGURE 1. Escharotomy is performed using either a scalpel or electrocautery set ...