A 57 year old caucasian man is brought to the emergency department after being rescued from his burning home by firefighters. His medical history includes only COPD, and his only medication is an albuterol-ipratropium metered-dose inhaler.
On exam, he is alert and in moderate pain. His temperature is 37.6 °C, blood pressure is 128/66 mm Hg, pulse rate is 109 beats per minute, and respiration rate is 20 breathes per minute; BMI is 30. Oxygen saturation is 98% while breathing 2 L/min oxygen by nasal cannula. There is snoot in his nares and throughout the oral pharynx. The oral mucosa is edematous. Burns are noted on the right upper extremity and lower chest. Cardiac examination reveals a regular rhythm. Pulmonary examination reveals a monophonic wheeze over the anterior chest, diffuse expiratory wheezes, and increased work of breathing.
Arterial blood gas studies breathing 30% oxygen reveal a pH of 7.32, a PCO2 of 50 mm Hg, and a PO2 of 78 mm Hg.
A chest radiograph shows increased lung volumes consistent with hyperinflation but no infiltrates.
Which of the following is the most appropriate next step in treating this patient's respiratory findings?
A. Administer a helium-oxygen mixture
B. Administer methylprednisolone
C. Perform endotracheal intubation
D. Start nebulized epinephrine
E. Start noninvasive ventilation