Firefighters have pulled a middle-aged male from a burning bedroom. The patient is unresponsive and has obvious deformity of his left ankle. His respirations are rapid, stridorous, and shallow. Your partner inserts an oropharyngeal airway and begins ventilating the patient with a bag-valve mask. Which one of the following actions would you perform next?

A) Instruct your partner to hyperventilate the patient.
B) Find out how long the patient was in the burning structure.
C) Check the patient's breath sounds.
D) Assess the patient's carotid pulse.

D