title: Letter: Smoking, carboxyhemoglobin levels, and oxygen therapy.
mesh_terms: D002263:Carboxyhemoglobin / Q000032:analysis*; D002908:Chronic Disease; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000097:blood* / Q000628:therapy; D010102:Oxygen Inhalation Therapy; D012907:Smoking
chemical_list: D006454:Hemoglobins; D002263:Carboxyhemoglobin