Oxygen in acute-on-chronic respiratory failure .
D000208:Acute Disease; D002908:Chronic Disease; D006801:Humans; D006935:Hypercapnia / Q000517:prevention & control; D000860:Hypoxia / Q000517:prevention & control; D008991:Monitoring, Physiologic; D010102:Oxygen Inhalation Therapy; D012131:Respiratory Insufficiency / Q000628:therapy*