title: Are oxygen-conserving devices effective for correcting exercise hypoxemia?
abstract: BACKGROUND
  Correction of exercise hypoxemia in advanced lung diseases is crucial and often challenging. However, oxygen-conserving devices have been introduced in the market with limited evidence of effectiveness. In the present study the efficacy of 2 oxygen-conserving devices, a pulse demand oxygen delivery (DOD) system and pendant reservoir cannula (PRC), were evaluated in subjects with COPD and interstitial lung disease (ILD).
  
  
  METHODS
  A cross-sectional, crossover study included 28 COPD and 31 ILD subjects with oxygen desaturation on the 6-min walk test (average S(pO2) < 88%). Each subject underwent 3 walk tests with DOD, PRC, and continuous oxygen flow by standard nasal cannula (CFNC), in random order, taking average S(pO2) ≥ 90% as the resaturation criterion.
  
  
  RESULTS
  Exercise desaturation was corrected in 79%, 79%, and 86% of COPD subjects with CFNC, DOD, and PRC, respectively, and in 77%, 61%, and 81% of ILD subjects with CFNC, DOD, and PRC, respectively. When compared to CFNC, the oxygen-conserving devices showed similar efficacy, except a lower performance for the DOD in the ILD subjects (P = .01).
  
  
  CONCLUSIONS
  Although these oxygen-conserving devices corrected exercise hypoxemia in most COPD and ILD subjects, correction was not achieved in about 20% of the severe COPD subjects, regardless of the device, and in nearly 40% of the ILD subjects with the DOD device. These findings underscore that individualized adjustment of oxygen flow is needed for optimal correction of exercise hypoxemia, especially with a DOD in an ILD patient. (ClinicalTrials.gov NCT01086891).
authors.affiliation: Pulmonology Department, Hospital Universitari Vall d'Hebron, and the Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain, and with the Centro de Investigación Biomédica en Red de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Sergi
authors.initials: S
authors.lastname: Martí
authors.forename: Virginia
authors.initials: V
authors.lastname: Pajares
authors.forename: Fátima
authors.initials: F
authors.lastname: Morante
authors.forename: Maria-Antònia
authors.initials: MA
authors.lastname: Ramón
authors.forename: Jordi
authors.initials: J
authors.lastname: Lara
authors.forename: Jaume
authors.initials: J
authors.lastname: Ferrer
authors.forename: Maria-Rosa
authors.initials: MR
authors.lastname: Güell
mesh_terms: D000368:Aged; D018592:Cross-Over Studies; D003430:Cross-Sectional Studies; D004867:Equipment Design; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D000860:Hypoxia / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D008171:Lung Diseases / Q000628:therapy*; D008297:Male; D010100:Oxygen / Q000494:pharmacology*; D010101:Oxygen Consumption; D010102:Oxygen Inhalation Therapy / Q000295:instrumentation*; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D010100:Oxygen
keywords: COPD; conservers; exercise test; interstitial lung disease; oxygen inhalation therapy; technology assessment