title: Domiciliary oxygen therapy improves sub-maximal exercise capacity and quality of life in chronic heart failure.
abstract: BACKGROUND
  A high prevalence of nocturnal hypoxia is noted in patients with chronic heart failure (CHF). Nocturnal hypoxia can be reversed by nasal oxygen or non-invasive assisted ventilation. However, controversy exists over the use of oxygen in CHF. We studied the effects of nocturnal nasal oxygen in CHF to demonstrate its effects on 6-min walk test, quality of life (QOL), NTproBNP, and echocardiographic parameters.
  
  
  METHODS
  Ten patients aged 70+/-9 years received domiciliary oxygen (4 l/min) for one month. Oxygen was administered for a minimum of 8h every night via nasal prongs.
  
  
  RESULTS
  A 17% improvement was seen in the 6-min walk test, 298+/-98 m to 351+/-100 m (p=0.005) and a 27% improvement in the QOL, which improved from 26+/-12 to 19+/-7 (p=0.017). Acquired echocardiographic measures including ejection fraction, pulmonary pressure and diastolic parameters did not change.
  
  
  CONCLUSIONS
  Nocturnal nasal oxygen has a significant impact on sub-maximal exercise capacity and QOL in CHF. Although a previous study has demonstrated harmful haemodynamic effects of acute oxygen administration in CHF; we did not detect any change in echocardiographic parameters using current two-dimensional imaging and Doppler studies. The lack of improvement in cardiac parameters suggests a peripheral mode of action.
authors.affiliation: Department of Cardiology, Flinders Medical Centre, Adelaide 5042, Australia.
authors.forename: Biju
authors.initials: B
authors.lastname: Paul
authors.forename: Majo
authors.initials: M
authors.lastname: Joseph
authors.forename: Carmine G
authors.initials: CG
authors.lastname: De Pasquale
mesh_terms: D000368:Aged; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D000860:Hypoxia / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D011788:Quality of Life; D012646:Self Administration; D013318:Stroke Volume / Q000502:physiology