Extremity compartment syndrome in burns

Overview

Extremity compartment syndrome in burns occurs when elevated pressure within a closed fascial compartment compromises tissue perfusion. In thermal burns, the primary mechanism is circumferential full-thickness eschar that restricts expansion of underlying tissues as edema develops during resuscitation. The resulting pressure elevation can compromise arterial inflow and venous drainage, leading to ischemia of muscle, nerve, and other compartment contents. Escharotomy, the longitudinal incision through constricting eschar, is the standard intervention for burn-induced compartment syndrome. Fasciotomy is indicated for high-voltage electrical injuries or when subfascial pressure remains elevated despite escharotomy ^[1][6].

Pathophysiology

Full-thickness circumferential burns produce a rigid, inelastic eschar that cannot accommodate the tissue swelling driven by capillary leak and fluid resuscitation. As interstitial edema increases beneath the unyielding eschar, compartment pressure rises. When compartment pressure exceeds the critical closing pressure of capillaries, microvascular perfusion fails. Muscle and nerve tolerate approximately 6 hours of ischemia before irreversible damage occurs ^[1]. In electrical injury, direct current-induced muscle necrosis and edema raise subfascial pressure independent of eschar restriction, necessitating fasciotomy rather than escharotomy ^[1].

Overresuscitation amplifies the risk of extremity compartment syndrome by increasing the volume of interstitial edema. Burns exceeding 40% TBSA with crystalloid volumes above predicted formula targets carry the highest risk VERIFY.

Assessment

Clinical assessment remains the cornerstone of diagnosis. The classic findings are pain on passive stretch, tense compartments, paresthesias, and absent distal pulses, but pain assessment is unreliable in patients with deep burns (insensate skin) or altered mental status.

Piccolo et al. described an algorithm for surgical decision-making using pulse oximetry and Doppler flowmetry ^[1]. In their series of 58 patients with circumferential or electrical burns, decisions to operate were based on clinical signs combined with oximetry below 90%, regardless of Doppler flow. Patients with negative Doppler but oximetry above 90% who were observed without surgery fared well with no circulatory or neurologic impairment at 3- and 6-month follow-up ^[1].

May et al. reported on the use of the Stryker intracompartmental pressure monitor for triage of circumferential limb burns, providing an objective measurement to supplement clinical assessment ^[4]. Dominic et al. compared wick and fiber-optic catheters for continuous compartment pressure monitoring in 14 burned extremities and found both systems correlated well on initial measurements but differed in fragility and obstruction rates ^[5]. They emphasized that direct pressure monitoring requires clinical judgment and cannot be used in isolation.

Compartment pressure measurement is adjunctive. An absolute threshold of 30 mmHg or a perfusion pressure (diastolic blood pressure minus compartment pressure) below 30 mmHg is generally used to indicate the need for intervention, though these values derive primarily from the orthopedic trauma literature rather than burn-specific studies VERIFY.

Management

Escharotomy is the first-line treatment for burn-induced extremity compartment syndrome. It involves full-thickness longitudinal incisions through the eschar along the medial and lateral aspects of the affected extremity, extending across joints as needed. Escharotomy relieves the circumferential constriction and allows tissue expansion, restoring perfusion. Distal pulses should be reassessed immediately after the procedure.

Fischer et al. evaluated enzymatic debridement with NexoBrid as an alternative to operative escharotomy in 13 patients with 20 circumferentially burned upper extremities ^[2]. Enzymatic debridement provided sufficient eschar removal in all patients, and none required conversion to conventional escharotomy. Functional outcomes at 11.9 months were favorable ^[2]. This approach represents a potential alternative in selected patients without established compartment syndrome, though it requires timely application and specific contraindications must be respected ^[2].

Liu et al. described conservative tangential excision as a replacement for escharotomy in 16 patients with heat-induced compartment syndrome ^[3]. All patients achieved adequate decompression of limbs (19 extremities) and chest/abdomen (5 areas) without need for fasciotomy, and no secondary damage to deep structures was observed ^[3].

Fasciotomy is indicated when subfascial pressures remain elevated after escharotomy, as occurs in electrical injury with deep muscle necrosis, crush injury, or prolonged ischemia. Carpal tunnel release should be considered in electrical injuries involving the upper extremity ^[1].

Controversies and Evidence Gaps

The evidence base for extremity compartment syndrome in burns consists predominantly of case series, retrospective studies, and expert opinion. No randomized trials compare different diagnostic thresholds or interventions. The role of continuous compartment pressure monitoring versus clinical assessment alone has not been settled. Enzymatic debridement as an alternative to escharotomy is supported by limited data and requires further study ^[2]. The optimal timing of escharotomy, the predictive value of specific Doppler or oximetry findings, and the incidence of unnecessary escharotomies performed on clinical suspicion alone are all areas lacking robust evidence.

References

[1] Piccolo NS et al. "Escharotomies, fasciotomies and carpal tunnel release in burn patients--review of the literature and presentation of an algorithm for surgical decision making." Handchir Mikrochir Plast Chir 2007;39(3):161-7. PMID: 17602377 [2] Fischer S et al. "Feasibility and safety of enzymatic debridement for the prevention of operative escharotomy in circumferential deep burns of the distal upper extremity." Surgery 2019;165(6):1100-1105. PMID: 30678870 [3] Liu J et al. "Conservative tangential excision instead of escharotomy in the treatment of compartment syndrome." Injury 2025;56(2):112069. PMID: 39662373 [4] May J et al. "Stryker intracompartmental pressure monitor in the triage of circumferential limb burns." Ann R Coll Surg Engl 2015;97(2):160-1. PMID: 25723700 [5] Dominic WJ et al. "Comparison of wick and fibreoptic catheters in measurement of interstitial pressures in burned extremities." Burns Incl Therm Inj 1988;14(2):125-9. PMID: 3134113 [6] Maitz PKM et al. "The management of the acutely burned upper extremity." J Hand Surg Am 1995;20(3 Pt 2):S28-34. PMID: 7996604