Oxygen behind the mask.
D006801:Humans; D006935:Hypercapnia / Q000628:therapy; D008397:Masks / Q000592:standards; D010100:Oxygen; D010102:Oxygen Inhalation Therapy / Q000295:instrumentation* / Q000379:methods; D012131:Respiratory Insufficiency / Q000628:therapy
D010100:Oxygen