A 52-year-old man comes to the physician for a 2-week history of shortness of breath. Vitals are within normal limits. Physical examination is unremarkable. Laboratory studies show:
Arterial pCO2 32 mmHg
Arterial pO2 98 mmHg
Arterial O2 content 13% (NR 17-21%)
Which of the following is the most likely explanation for these findings?
Anemia
Drug-induced alveolar hypoventilation
High altitude residence
Alveolar-arterial mismatch
Voluntary hyperventilation
