Fat embolism, ARDS and the Macklin effect: how modulating mechanical power changes the outcome

Abstract

Introduction: Fat embolism syndrome (FES) is an uncommon but potentially fatal complication of major orthopedic surgery and long bone trauma, characterized by acute respiratory failure, neurological compromise, and cutaneous petechiae. The coexistence of FES with severe barotrauma, tension pneumothorax, and subsequent Macklin effect with massive subcutaneous emphysema creates a scenario of extremely high mortality, and there are no specific guidelines for its management. Case presentation: A 72-yearold man presented with fulminant neuropulmonary FES following total knee arthroplasty. His condition was complicated by a right tension pneumothorax and, subsequently, by a massive Macklin effect and grade IV subcutaneous emphysema. Management included power-assisted ultraprotective ventilation, pleural and subcutaneous decompression, and correction of critical illness-related corticosteroid deficiency, hypocalcemia, and intra-abdominal hypertension. The strategy focused on limiting mechanical power (MP < 15 J/min), maintaining low conduction pressure, performing decompression fenestrations, and applying aggressive and targeted abdominal decompression, within the context of hemodynamic optimization and negative fluid balance. Sealing of the pneumomediastinum, progressive resolution of subcutaneous emphysema, improvement in static compliance, and successful weaning from mechanical ventilation were achieved, with functional discharge from the intensive care unit in approximately 20 days. Discussion: In patients with gastric syndrome complicated by sequential barotrauma and the Macklin effect, an integrated strategy combining modulation of mechanical power, abdominal subcutaneous pleural decompression, and correction of endocrine and metabolic dysfunctions can transform a condition with a poor prognosis into a favorable recovery.