A 46-year-old male with a 40-pack-year smoking history, pres…

A 46-year-old male with a 40-pack-year smoking history, presents with a two-year history of worsening dyspnea and a one-month history of dry cough. Patient gives no history of fever, chills, chest pain, or wheeze. A chest X-ray shows hyperinflated lungs with bullae, flattened diaphragm, and no cardiomegaly or areas of consolidation. Pulmonary function tests (PFT) reveal a decrease in FEV1 along with reduction of FEV1/FVC ratio. These findings are characteristic of which of the following conditions?

A 12-year-old boy is brought to the Emergency Department wit…

A 12-year-old boy is brought to the Emergency Department with sudden onset of dyspnea with wheezing. The patient had a similar episode a month ago. An arterial blood gas shows hypoxemia, hypercapnia and acidosis. The chest X-ray shows clear lung fields. The most likely accompanying laboratory finding in this case would be: