True about Flail chest are A/E-

• A. PaO2 < 40 with FiO2 > 60 treated with intubation and PEEP
• B. Paradoxical movement may not be seen in conscious patients
• C. Fracture of atlest 3 ribs
• D. If overlapping of fractured ribs with severe displacement is seen than patients are treated surgically with open reduction and fixation