title: Air stacking and chest compression increase peak cough flow in patients with Duchenne muscular dystrophy.
abstract: OBJECTIVE
  To evaluate cough efficiency using two manually-assisted cough techniques.
  
  
  METHODS
  We selected 28 patients with Duchenne muscular dystrophy. The patients were receiving noninvasive nocturnal ventilatory support and presented FVC values < 60% of predicted. Peak cough flow (PCF) was measured, with the patient seated, at four time points: at baseline, during a spontaneous maximal expiratory effort (MEE); during an MEE while receiving chest compression; during an MEE after air stacking with a manual resuscitation bag; and during an MEE with air stacking and compression (combined technique). The last three measurements were conducted in random order. The results were compared using Pearson's correlation test and ANOVA with repeated measures, followed by Tukey's post-hoc test (p < 0.05).
  
  
  RESULTS
  The mean age of the patients was 20 + or - 4 years, and the mean FVC was 29 + or - 12%. Mean PCF at baseline, with chest compression, after air stacking and with the use of the combined technique was 171 + or - 67, 231 + or - 81, 225 + or - 80, and 292 + or - 86 L/min, respectively. The results obtained with the use of the combined technique were significantly better than were those obtained with the use of either technique alone (F[3.69] = 67.07; p < 0.001).
  
  
  CONCLUSIONS
  Both chest compression and air stacking techniques were efficient in increasing PCF. However, the combination of these two techniques had a significant additional effect (p < 0.0001).
authors.affiliation: Sleep Medicine and Biology Division of the Psychobiology Department of the Universidade Federal de São Paulo - UNIFESP, Federal University of São Paulo - São Paulo, Brazil. magneide@gmail.com
authors.forename: Magneide Fernandes
authors.initials: MF
authors.lastname: Brito
authors.forename: Gustavo Antonio
authors.initials: GA
authors.lastname: Moreira
authors.forename: Márcia
authors.initials: M
authors.lastname: Pradella-Hallinan
authors.forename: Sergio
authors.initials: S
authors.lastname: Tufik
mesh_terms: D035641:Chest Wall Oscillation / Q000379:methods*; D003131:Combined Modality Therapy / Q000592:standards; D003371:Cough / Q000503:physiopathology*; D004812:Epidemiologic Methods; D006801:Humans; D020388:Muscular Dystrophy, Duchenne / Q000628:therapy*; D010366:Peak Expiratory Flow Rate / Q000502:physiology*; D012121:Respiration, Artificial / Q000295:instrumentation; D012138:Respiratory Therapy / Q000379:methods* / Q000592:standards; D012151:Resuscitation / Q000295:instrumentation; D014797:Vital Capacity / Q000502:physiology; D055815:Young Adult