A 30 yrs old male had multiple fractures after a road traffic accident. In the emergency room, the patient develops, tachypnea and dyspnea & was given high concentration of oxygen. But his condition deteriorates. Blood gas analysis was performed, which shows : PaO2 = 50mmHg ; PaCO2 = 35mmHg ; pH = 7.37 ; FiO2 = 50% What is the most likely cause for the worsening breathlessness in the patient ?
a) Tension pneumothorax b) Pulmonary embolism c) Adult respiratory distress syndrome d) Shock