A Patient Involved in a House Fire Is Brought by Ambulance

A patient involved in a house fire is brought by ambulance to your emergency department.He is breathing spontaneously but appears agitated.He does not respond appropriately to questions.You assume he has inhaled carbon monoxide and has carbon monoxide (CO) poisoning.Your first action is to

A) ask the physician to order a STAT chest radiograph to rule out a pneumothorax.
B) apply a pulse oximeter to one of his unburned fingers.
C) call the local hyperbaric chamber to check on its availability.
D) administer 100% high-flow oxygen via a nonrebreathing mask.