title: Use of heliox in critical upper airway obstruction. Physical and physiologic considerations in choosing the optimal helium:oxygen mix.
abstract: Heliox has a lower density than oxygen and nitrogen, and can improve ventilation rapidly in patients with critical upper airway obstruction. The choice of the best helium:oxygen ratio depends on whether the predominant problem is hypercarbia or hypoxia. In the former situation, 80% helium should be used, and in the latter, 100% oxygen is appropriate.
authors.affiliation: Department of Anaesthesia and Intensive Care, Faculty of Medicine, Prince of Wales Hospital Shatin, The Chinese University of Hong Kong, NT, Shatin, Hong Kong. hoamh@hotmail.com
authors.forename: Anthony M H
authors.initials: AM
authors.lastname: Ho
authors.forename: Peter W
authors.initials: PW
authors.lastname: Dion
authors.forename: Manoj K
authors.initials: MK
authors.lastname: Karmakar
authors.forename: David C
authors.initials: DC
authors.lastname: Chung
authors.forename: Beng A
authors.initials: BA
authors.lastname: Tay
mesh_terms: D000402:Airway Obstruction / Q000628:therapy*; D002245:Carbon Dioxide / Q000032:analysis; D006371:Helium / Q000008:administration & dosage*; D006801:Humans; D000860:Hypoxia / Q000628:therapy; D008962:Models, Theoretical; D010100:Oxygen / Q000008:administration & dosage*; D010313:Partial Pressure
chemical_list: D002245:Carbon Dioxide; D006371:Helium; C038949:heliox; D010100:Oxygen