A 72 yo man arrives the UF Family Medicine Clinic for his qu…
A 72 yo man arrives the UF Family Medicine Clinic for his quarterly checkup. He is over weight (BMI = 31) and his diet largely consists of processed foods. He takes Captopril for hypertension (BP= 180/140, without meds) and Metformin for diabetes (A1C = 9.3% without meds). He tells you that since his last visit three months prior, he has quit smoking. He states that the urge to return to smoking is strong, as he smoked 1-2 packs of cigarettes per day, for 23 years. Respiratory rate is 29 bpm. Breathing room air, his lab data are as follows; pH = 7.47, PaCO2 = 24 mm Hg, PaO2 = 58 mm Hg, HCO3- = 17 mEq/L, and SpO2 = 88%. The most likely cause of the patient’s hypoxemia is