title: Long-Term Effects of Lung Volume Recruitment on Maximal Inspiratory Capacity and Vital Capacity in Duchenne Muscular Dystrophy.
abstract: BACKGROUND
  Lung volume recruitment therapy slows rate of decline of lung function in neuromuscular disease, possibly due to enhanced airway clearance, reduced atelectasis, or prevention of chest wall contractures.
  
  
  OBJECTIVE
  To determine if lung volume recruitment maintains maximal insufflation capacity (MIC), despite decline in VC.
  
  
  METHODS
  This was a retrospective cohort study (1991-2008) of individuals with Duchenne muscular dystrophy at pediatric and adult tertiary centers. Lung volume recruitment was prescribed twice daily, according to protocol. Changes over time in MIC, VC percentage predicted, the difference between MIC and VC, maximum inspiratory and expiratory pressures, and assisted and unassisted peak cough flow (PCF) were assessed using linear mixed effects models.
  
  
  RESULTS
  Sixteen individuals, 8.6 to 33.0 years old at initiation of lung volume recruitment, with median VC percentage predicted of 13.5 (interquartile range, 8.0-20.3), were followed over a median of 6.1 years (range, 1.7-16.1 yr). MIC-VC differences were stable (change, 0.02 L/yr; P = 0.06). Post-lung volume recruitment, compared with pretreatment, rate of decline in VC decreased from 4.5% predicted/yr to 0.5% predicted/yr (P < 0.001). Maximal inspiratory and expiratory pressures were unchanged (P = 0.08, 0.59 respectively). Assisted-spontaneous PCF difference was maintained (slope, -1.59 L/min/yr, P = 0.35).
  
  
  CONCLUSIONS
  With lung volume recruitment therapy, MIC-VC differences were stable over time, indicating that respiratory system compliance remains stable, despite a loss in VC, in individuals with Duchenne muscular dystrophy. Decline in VC was significantly attenuated, and assisted PCF was maintained in a clinically effective range.
authors.affiliation: 1 Division of Respiratory Medicine, Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada.|2 Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.|3 Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada.
authors.forename: Sherri L
authors.initials: SL
authors.lastname: Katz
authors.affiliation: 2 Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.|4 Clinical Research Unit, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Barrowman
authors.affiliation: 3 Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada.
authors.forename: Andrea
authors.initials: A
authors.lastname: Monsour
authors.affiliation: 2 Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Santana
authors.initials: S
authors.lastname: Su
authors.affiliation: 4 Clinical Research Unit, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada.
authors.forename: Lynda
authors.initials: L
authors.lastname: Hoey
authors.affiliation: 2 Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.|5 Division of Respiratory Medicine, The Ottawa Hospital Rehabilitation Centre, Ottawa, Ontario, Canada; and.|6 The Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
authors.forename: Douglas
authors.initials: D
authors.lastname: McKim
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D015331:Cohort Studies; D006801:Humans; D007320:Inspiratory Capacity / Q000502:physiology*; D008168:Lung / Q000503:physiopathology; D008170:Lung Compliance / Q000502:physiology*; D008297:Male; D020388:Muscular Dystrophy, Duchenne / Q000503:physiopathology / Q000534:rehabilitation*; D011175:Positive-Pressure Respiration / Q000379:methods; D012138:Respiratory Therapy / Q000379:methods*; D012189:Retrospective Studies; D013995:Time; D014797:Vital Capacity / Q000502:physiology*; D055815:Young Adult
keywords: VC; cough; neuromuscular diseases; pulmonary function test; respiratory therapy