title: Authors' Reply.
authors.affiliation: Department of Pneumology, University Hospital, Freiburg, Germany.
authors.forename: Emelie
authors.initials: E
authors.lastname: Ekkernkamp
authors.forename: Michael
authors.initials: M
authors.lastname: Dreher
mesh_terms: D002245:Carbon Dioxide / Q000097:blood*; D005260:Female; D006801:Humans; D006935:Hypercapnia; D059725:Interactive Ventilatory Support / Q000379:methods*; D008297:Male; D011175:Positive-Pressure Respiration / Q000379:methods*; D029424:Pulmonary Disease, Chronic Obstructive; D012890:Sleep / Q000502:physiology*
chemical_list: D002245:Carbon Dioxide