Case Report: Electrical impedance tomography-guided ultra-protective lung ventilation during veno-venous extracorporeal membrane oxygenation support for fat embolism syndrome complicated by severe acute respiratory distress syndrome.

Background: Fat embolism syndrome (FES) is a rare complication of severe multiple trauma. Electrical impedance tomography (EIT) is a noninvasive, real-time, bedside tool for monitoring regional pulmonary ventilation. Veno-venous extracorporeal membrane oxygenation (VV-ECMO) may improve outcomes in critically ill patients in whom conventional mechanical ventilation fails. Ultra-protective lung ventilation strategy (ULPVS) uses very low tidal volumes to markedly reduce lung stress and mitigate ventilator-induced lung injury (VILI). Case presentation: In June 2025, a 57-year-old woman was admitted to the Department of Orthopedics with a femoral shaft fracture following a motor vehicle accident. Severe respiratory distress developed postoperatively, and she was urgently transferred to the ICU. Based on laboratory findings, chest CT findings, and Oil Red O staining of bronchoalveolar lavage fluid (BALF), FES complicated by severe acute respiratory distress syndrome (ARDS) was considered. In addition to conventional treatment, VV-ECMO was initiated to provide gas-exchange support. An ULPVS was implemented during the early phase of ventilation to reduce the risk of VILI, and EIT was used to guide ventilatory management and titration of the optimal Positive end-expiratory pressure (PEEP) Following these interventions, static lung compliance increased from 46 mL/cmH Conclusion: Bedside EIT enables dynamic assessment of pulmonary status and may assist in optimizing ventilator settings, providing a useful reference for the management of FES complicated by severe ARDS.