When the skin suffers a full-thickness burn (eschar) it loses its elasticity. At the same time, there is a shifting of fluid in the underlying subcutaneous tissues into the adjacent interstitial space. With this fluid shift comes an increase in tissue pressure. The inelasticity of the overlying burned skin, when it is circumferential on an extremity, can cause these tissue pressures to exceed the pulse pressure, thereby compromising blood flow to the extremity. On the anterior trunk, a full-thickness burn eschar can compromise respiratory mechanics, which is seen clinically as the inability of the patient to ventilate followed by the inability to oxygenate. To relieve these pressures and restore perfusion and/or correct respiratory mechanics, escharotomies are performed.
Attention should be given to hemodynamic stability of the patient, as well as close fluid and electrolyte management in the case of burn patients. Preoperative antibiotics are essential to prevent infection.
Because all cutaneous nerves have been destroyed in the area of full-thickness burn, no anesthetic is required prior to performing an escharotomy.
For escharotomy, using either a scalpel or electrocautery set to “CUT,” incisions are made through the entire thickness of the circumferential eschar until subcutaneous fat is observed. The escharotomy incision should be placed on the medial and lateral aspect of the circumferential full-thickness extremity burn and should extend the entire length of the eschar (figures 1 and 2). On the anterior chest, the escharotomies should be made along the lateral aspects of the trunk, with additional incisions placed across the upper trunk and lower trunk so that they form a rectangle (figure 3). When performing escharotomies on the hand, the incisions should be placed on the dorsum between the metacarpals. If necessary, they can be extended onto the ulnar aspect of each digit (figure 4).
When correctly made, the eschar will expand open and the subcutaneous fat will be seen (figure 1). If subcutaneous fat is not observed, the escharotomy should be made deeper. Any bleeding encountered after the escharotomy has been performed is venous and will stop with application of thrombin-soaked pads.
Escharotomies are covered with the same burn dressings being used to cover the associated full-thickness burn. Escharotomies are not closed. Because they exist in full-thickness burn, eventually they will be included in the debridement of the burn wound. Management of the patient’s concomitant medical problems is of utmost priority.