title: Letter: Oxygen therapy in chronic respiratory failure.
mesh_terms: D002245:Carbon Dioxide; D002908:Chronic Disease; D006801:Humans; D006935:Hypercapnia / Q000150:complications; D010101:Oxygen Consumption; D010102:Oxygen Inhalation Therapy; D011660:Pulmonary Heart Disease; D012131:Respiratory Insufficiency / Q000628:therapy*
chemical_list: D002245:Carbon Dioxide