Respiratory distress.
D000368:Aged; D001007:Anxiety / Q000150:complications; D002245:Carbon Dioxide / Q000097:blood; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000097:blood / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D011785:Quality Assurance, Health Care; D012131:Respiratory Insufficiency / Q000097:blood / Q000628:therapy*; D012907:Smoking / Q000009:adverse effects
D002245:Carbon Dioxide; D010100:Oxygen