title: During exercise non-invasive ventilation in chronic restrictive respiratory failure.
abstract: BACKGROUND
  Exercise intolerance limits chronic restrictive respiratory failure (CRF) patients from participating in daily activities. The specific modalities that could improve exercise tolerance in these patients remain to be established.
  
  
  OBJECTIVE
  To investigate exercise endurance and associated physiological responses with non-invasive ventilation (NIV) during exercise in restrictive CRF patients.
  
  
  METHODS
  Eighteen patients (63+/-11 years, total lung capacity (TLC)=59+/-16% of predicted value) performed maximal exercise in spontaneous breathing conditions (MWLE) and during two constant workload exercise (CWLE) tests at 75% Pmax, with or without NIV in random order. "NIV Responders" were defined by an increase in CWLE duration of more than 50% when using NIV.
  
  
  RESULTS
  For the whole group, CWLE duration when using NIV increased from 5.6+/-4.6 to 9.6+/-8.1 min. Increase in CWLE duration correlated with reduction in heart rate and oxygen desaturation, and dyspnea relief during exercise. NIV responders (n=9) showed more severe lung restriction (TLC: 2.6+/-0.7 versus 3.5+/-1.1L; forced vital capacity: 1.0+/-0.16 versus 1.46+/-0.38 L). At the end of MWLE, responders had a lower Vt (0.60+/-0.09 versus 0.89+/-0.34 L), a higher dead-space ratio (0.51+/-0.06 versus 0.38+/-0.12) and lower oxygen pulse (4.5+/-1.2 versus 7.4+/-3.9 ml/beat).
  
  
  CONCLUSIONS
  In severely restrictive patients, NIV during exercise significantly improved exercise duration and tolerance and increased alveolar ventilation.
  
  
  BACKGROUND
  The enrollment of the patients started before July 1, 2005.
authors.affiliation: INSERM ERI 0017, HP2 Laboratory, Joseph Fourier University, Grenoble, France. JCBorel@chu-grenoble.fr
authors.forename: Jean-Christian
authors.initials: JC
authors.lastname: Borel
authors.forename: Bernard
authors.initials: B
authors.lastname: Wuyam
authors.forename: Nathalie
authors.initials: N
authors.lastname: Chouri-Pontarollo
authors.forename: Chrystèle
authors.initials: C
authors.lastname: Deschaux
authors.forename: Patrick
authors.initials: P
authors.lastname: Levy
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Pépin
mesh_terms: D000368:Aged; D005081:Exercise Therapy / Q000379:methods*; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D010807:Physical Endurance; D012121:Respiration, Artificial / Q000379:methods*; D012131:Respiratory Insufficiency / Q000503:physiopathology / Q000628:therapy*; D018709:Statistics, Nonparametric; D014109:Total Lung Capacity; D016896:Treatment Outcome