A 32-year-old female presents to the emergency department from an orthopedic outpatient clinic with worsening respiratory distress and altered mental status. She sustained a closed comminuted right tibia-fibula fracture two days prior in a motor vehicle collision, initially managed with temporary splinting. On admission to the emergency department, she was oriented but complained of diffuse muscle aches. Overnight, her condition deteriorated rapidly. On physical examination, she is confused and lethargic, with a Glasgow Coma Scale (GCS) of 10 (E3V3M4). Her temperature is 38.0 C (100.4 F), blood pressure is 95/60 mm Hg, pulse is 120/min, and respiration is 30/min, with shallow breaths. Pulse oximetry on room air is 85%, improving to 92% with a non-rebreather mask. Auscultation reveals diffuse crackles in both lung fields, and her heart is tachycardic. A notable finding is the presence of widespread petechial hemorrhages visible on her conjunctivae, neck, and upper chest. The right lower extremity is swollen, and the fracture site feels unstable. An electrocardiogram shows sinus tachycardia without ischemic changes. Her chest x-ray demonstrates bilateral patchy infiltrates, suggestive of acute lung injury. Considering the evolving clinical picture, what is the most likely diagnosis, and what should be the immediate, definitive therapeutic intervention to prevent further complications?