A 24-year-old man with epilepsy refractory to valproic acid, phenytoin, and levetiracetam undergoes magnetic resonance imaging of his brain while monitored by anesthetic care. He wakes up screaming in pain due to an electrocardiogram lead having caused a significant thermal burn circumferentially around his left leg. He is admitted to the medical intensive care unit for continuous electroencephalogram monitoring while on a midazolam infusion for seizure suppression and supportive care for his burn. Overnight, the nurse continued to increase the patient's midazolam infusion rate, but she also noticed that his left toes were cold to the touch with significant edema. His temperature is now 100°F (37.8°C), blood pressure is 110/75 mmHg, pulse is 80/min, respirations are 10/min and oxygen saturation is 95% on 2 liters nasal cannula. No dorsalis pedis or posterior tibial pulses are detected on the left lower extremity. A delta pressure of 25 mmHg is obtained in the left leg. What is the most appropriate next step in management?
Amputation
Escharotomy
Fasciotomy
Intravenous fluid infusion based on Parkland formula
Escharotomy
This patient with a circumferential burn due to an ECG cable wrapped around his leg in an MRI machine now has clear evidence of compartment syndrome due to the eschar. The most appropriate next step in management is emergent escharotomy to restore blood flow.

Burns can be caused by chemical, thermal, electrical, and radiation sources. The initial inflammation causes vasodilatation and hyperemia, which can progress to edema and local microvascular thrombosis. If not promptly addressed, tissue necrosis and irreversible damage can occur. Circumferential burns can evolve into eschars that constrict blood flow and cause distal compartment syndrome. A delta pressure (diastolic pressure minus local compartment pressure) lower than 30 mmHg is diagnostic. In the case of eschar-induced compartment syndrome, the most appropriate next step is escharotomy to alleviate pressure.

Ormiston and Marappa-Ganeshan review the evidence regarding the diagnosis and treatment of patients with compartment syndrome. They discuss how this condition can be caused by many different pathologies including burns. They recommend the emergent release of constrictive structures.

Incorrect Answers:
Answer A: Amputation may be necessary if the distal limb is completely necrotic and not salvageable. Timely release of the eschar can allow for reperfusion of the limb and prevent this outcome.

Answer C: Fasciotomy is the treatment of choice for compartment syndrome not due to a circumferential eschar, but in this case the least invasive surgical intervention should be performed first without releasing all the compartments of the lower leg. If escharotomy does not relieve the compartment syndrome then fasciotomy may be required.

Answer D: Intravenous fluid infusion based on the Parkland formula is part of comprehensive burn management, but would not address the underlying compartment syndrome, which is more urgent at this time.

Answer E: Transfer to a specialized burn center can be considered since circumferential burns are one of the admission criteria, but early escharotomy should be performed first.

Bullet Summary:
Circumferential burns that cause eschars and compartment syndrome require an escharotomy.