title: Ambulatory pulmonary artery pressure monitoring during sleep and exercise in normal individuals and patients with COPD.
abstract: BACKGROUND
  Pulmonary hypertension is a common complication of chronic obstructive airways disease (COPD) and its presence implies a poor prognosis. However, it is difficult to measure and its specific contribution to symptoms is difficult to quantify. A micromanometer tipped pulmonary artery catheter was used to measure pulmonary artery pressure (PAP) during sleep and on exercise.
  
  
  METHODS
  Ten patients (five with COPD receiving long term oxygen therapy and five normal individuals) were studied. Pulmonary artery pressure was recorded continuously during two periods of sleep (breathing oxygen followed by air for the COPD group) and during exercise.
  
  
  RESULTS
  In the COPD group PAP during sleep on oxygen was significantly lower than PAP during sleep breathing air (mean (SD) difference 9.6 (5.3) mm Hg, 95% CI 4.9 to 14.3, p= 0.016). PAP during exercise was not significantly different from PAP during sleep breathing air (mean (SD) difference 0.8 (8.9) mm Hg, 95% CI -7.0 to 8.6, p= 0.851). In normal individuals the group mean (SD) PAP was 15 (5.9) mm Hg for the first nocturnal period and 15 (5.7) mm Hg for the second nocturnal period. PAP during exercise was not significantly different from PAP during sleep breathing air (mean (SD) difference 3.3 (2.2) mm Hg, 95% CI 1.1 to 5.5, p= 0.061).
  
  
  CONCLUSIONS
  In patients with COPD, PAP rose significantly during sleep to levels similar to those measured during exercise, but this could be reversed with oxygen.
authors.affiliation: Monklands District General Hospital, Airdrie ML6 0JS, UK.
authors.forename: D A
authors.initials: DA
authors.lastname: Raeside
authors.forename: A
authors.initials: A
authors.lastname: Brown
authors.forename: K R
authors.initials: KR
authors.lastname: Patel
authors.forename: D
authors.initials: D
authors.lastname: Welsh
authors.forename: A J
authors.initials: AJ
authors.lastname: Peacock
mesh_terms: D000328:Adult; D000368:Aged; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000209:etiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D010100:Oxygen / Q000627:therapeutic use; D011651:Pulmonary Artery / Q000502:physiology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000503:physiopathology*; D011669:Pulmonary Wedge Pressure / Q000502:physiology*; D012890:Sleep / Q000502:physiology
chemical_list: D010100:Oxygen