title: Nocturnal non-invasive nasal ventilation in stable hypercapnic COPD: a randomised controlled trial.
abstract: BACKGROUND
  Sleep hypoventilation has been proposed as a cause of progressive hypercapnic respiratory failure and death in patients with severe chronic obstructive pulmonary disease (COPD). A study was undertaken to determine the effects of nocturnal non-invasive bi-level pressure support ventilation (NIV) on survival, lung function and quality of life in patients with severe hypercapnic COPD.
  
  
  METHODS
  A multicentre, open-label, randomised controlled trial of NIV plus long-term oxygen therapy (LTOT) versus LTOT alone was performed in four Australian University Hospital sleep/respiratory medicine departments in patients with severe stable smoking-related COPD (forced expiratory volume in 1 s (FEV1.0) <1.5 litres or <50% predicted and ratio of FEV1.0 to forced vital capacity (FVC) <60% with awake arterial carbon dioxide tension (PaCO2) >46 mm Hg and on LTOT for at least 3 months) and age <80 years. Patients with sleep apnoea (apnoea-hypopnoea index >20/h) or morbid obesity (body mass index >40) were excluded. Outcome measures were survival, spirometry, arterial blood gases, polysomnography, general and disease-specific quality of life and mood.
  
  
  RESULTS
  144 patients were randomised (72 to NIV + LTOT and 72 to LTOT alone). NIV improved sleep quality and sleep-related hypercapnia acutely, and patients complied well with therapy (mean (SD) nightly use 4.5 (3.2) h). Compared with LTOT alone, NIV (mean follow-up 2.21 years, range 0.01-5.59) showed an improvement in survival with the adjusted but not the unadjusted Cox model (adjusted hazard ratio (HR) 0.63, 95% CI 0.40 to 0.99, p = 0.045; unadjusted HR 0.82, 95% CI 0.53 to 1.25, p = NS). FEV1.0 and PaCO2 measured at 6 and 12 months were not different between groups. Patients assigned to NIV + LTOT had reduced general and mental health and vigour.
  
  
  CONCLUSIONS
  Nocturnal NIV in stable oxygen-dependent patients with hypercapnic COPD may improve survival, but this appears to be at the cost of worsening quality of life.
  
  
  BACKGROUND
  ACTRN12605000205639.
authors.affiliation: Adelaide Institute for Sleep Health, Repatriation General Hospital and Flinders University, Australia. doug.mcevoy@health.sa.gov.au
authors.forename: R D
authors.initials: RD
authors.lastname: McEvoy
authors.forename: R J
authors.initials: RJ
authors.lastname: Pierce
authors.forename: D
authors.initials: D
authors.lastname: Hillman
authors.forename: A
authors.initials: A
authors.lastname: Esterman
authors.forename: E E
authors.initials: EE
authors.lastname: Ellis
authors.forename: P G
authors.initials: PG
authors.lastname: Catcheside
authors.forename: F J
authors.initials: FJ
authors.lastname: O'Donoghue
authors.forename: D J
authors.initials: DJ
authors.lastname: Barnes
authors.forename: R R
authors.initials: RR
authors.lastname: Grunstein
mesh_terms: D000339:Affect; D000368:Aged; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D006935:Hypercapnia / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D010313:Partial Pressure; D011175:Positive-Pressure Respiration / Q000379:methods*; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D011788:Quality of Life; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D002245:Carbon Dioxide