title: Effects of a helium/oxygen mixture on individuals' lung function and metabolic cost during submaximal exercise for participants with obstructive lung diseases.
abstract: BACKGROUND
  Helium/oxygen therapies have been studied as a means to reduce the symptoms of obstructive lung diseases with inconclusive results in clinical trials. To better understand this variability in results, an exploratory physiological study was performed comparing the effects of helium/oxygen mixture (78%/22%) to that of medical air.
  
  
  METHODS
  The gas mixtures were administered to healthy, asthmatic, and chronic obstructive pulmonary disease (COPD) participants, both moderate and severe (6 participants in each disease group, a total of 30); at rest and during submaximal cycling exercise with equivalent work rates. Measurements of ventilatory parameters, forced spirometry, and ergospirometry were obtained.
  
  
  RESULTS
  There was no statistical difference in ventilatory and cardiac responses to breathing helium/oxygen during submaximal exercise. For asthmatics, but not for the COPD participants, there was a statistically significant benefit in reduced metabolic cost, determined through measurement of oxygen uptake, for the same exercise work rate. However, the individual data show that there were a mixture of responders and nonresponders to helium/oxygen in all of the groups.
  
  
  CONCLUSIONS
  The inconsistent response to helium/oxygen between individuals is perhaps the key drawback to the more effective and widespread use of helium/oxygen to increase exercise capacity and for other therapeutic applications.
authors.affiliation: Inamed GmbH, Gauting, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Häussermann
authors.affiliation: Inamed GmbH, Gauting, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Schulze
authors.affiliation: Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, Les Loges-en-Josas, France ; Department of Mechanical Engineering, Lafayette College, Easton, PA, USA.
authors.forename: Ira M
authors.initials: IM
authors.lastname: Katz
authors.affiliation: Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Martin
authors.affiliation: Inamed GmbH, Gauting, Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: Herpich
authors.affiliation: Inamed GmbH, Gauting, Germany.
authors.forename: Theresa
authors.initials: T
authors.lastname: Hunger
authors.affiliation: Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, Les Loges-en-Josas, France.
authors.forename: Joëlle
authors.initials: J
authors.lastname: Texereau
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D000368:Aged; D001249:Asthma / Q000628:therapy*; D015444:Exercise / Q000502:physiology*; D017079:Exercise Tolerance; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006371:Helium / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000627:therapeutic use*; D029424:Pulmonary Disease, Chronic Obstructive / Q000628:therapy*; D013147:Spirometry
chemical_list: D006371:Helium; D010100:Oxygen
keywords: COPD; asthma; exercise; heliox; helium/oxygen; inspiratory capacity; obstructive airway diseases; oxygen uptake