A 22 year old male is admitted with fracture of the left femur. Two days later, he becomes mildly confused, has a respiratory rate of 40/min and scattered patechial rash on his upper torso. Chest X-ray shows patchy alveolar opacities bilaterally. His aerial blood gas analysis is abnormal. The most likely diagnosis is
Cerebral oedema with early neurogenic pulmonary oedema Pulmonary thrombo-embolism Chest contusion Fat embolism