title: Is there an optimal level of positive expiratory pressure (PEP) to improve walking tolerance in patients with severe COPD?
abstract: BACKGROUND
  The application of positive expiratory pressure (PEP) devices during exercise had been proposed in order to counteract the pulmonary hyperinflation, reduce the dyspnea and thus increase the exercise tolerance in patients with severe chronic obstructive pulmonary disease (COPD). This randomized controlled crossover trial investigated the effect of two different levels of PEP (1 cmH2O and 10 cmH2O) on distance covered at 6minute walk test (6MWT) in patients with severe COPD. Secondary outcomes were the evaluation of PEP effects on physiological and pulmonary function variables.
  
  
  METHODS
  Seventy-two severe COPD patients, referred to our hospitals as in and out patients, were recruited. A basal 6MWT without devices was performed on the first day, and then repeated with PEP 1 cmH2O (PEP1) and 10 cmH2O (PEP10), with a randomized crossover design. Slow and forced spirometries, including the inspiratory capacity measure, were repeated before and after each 6MWT.
  
  
  RESULTS
  50 patients (average age 69,92 year, mean FEV1 41,42% of predicted) concluded the trial. The 6MWT improved significantly among both PEP levels and baseline (323,8 mt at baseline vs. 337,8 PEP1 and 341,8 PEP10; p<.002 and p<.018, respectively). The difference between PEP10 and PEP1 did not reach the significance. No improvements were found in pulmonary function, symptoms and physiological variables after the 6MWT.
  
  
  CONCLUSIONS
  In patients with severe COPD, the application of 1 cmH2O of PEP seems to improve the exercise tolerance as 10 cmH2O, with similar dyspnea. Further studies should investigate the effects of low levels of PEP on aerobic training programs.
authors.affiliation: Unidad de Rehabilitación Respiratoria, Hospital di Sestri Levante ASL4, Chiavarese, Italia.
authors.forename: Davide
authors.initials: D
authors.lastname: Russo
authors.affiliation: Unidad de Rehabilitación Pulmonar, Fondazione S. Maugeri IRCCS, Lumezzane, BS, Italia.
authors.forename: Carla
authors.initials: C
authors.lastname: Simonelli
authors.affiliation: Unidad de Rehabilitación Pulmonar, Fondazione S. Maugeri IRCCS, Lumezzane, BS, Italia.
authors.forename: Mara
authors.initials: M
authors.lastname: Paneroni
authors.affiliation: Unidad de Rehabilitación Pulmonar, Fondazione S. Maugeri IRCCS, Lumezzane, BS, Italia.
authors.forename: Manuela
authors.initials: M
authors.lastname: Saleri
authors.affiliation: Unidad de Rehabilitación Respiratoria, Hospital di Sestri Levante ASL4, Chiavarese, Italia.
authors.forename: Ines Maria Grazia
authors.initials: IM
authors.lastname: Piroddi
authors.affiliation: Unidad de Estadística, ASL4, Chiavarese, Italia.
authors.forename: Francesco
authors.initials: F
authors.lastname: Cardinale
authors.affiliation: Unidad de Rehabilitación Pulmonar, Fondazione S. Maugeri IRCCS, Lumezzane, BS, Italia.
authors.forename: Michele
authors.initials: M
authors.lastname: Vitacca
authors.affiliation: Unidad de Rehabilitación Respiratoria, Hospital di Sestri Levante ASL4, Chiavarese, Italia. Electronic address: antonellonicolini@gmail.com.
authors.forename: Antonello
authors.initials: A
authors.lastname: Nicolini
mesh_terms: D000368:Aged; D018592:Cross-Over Studies; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D016037:Single-Blind Method; D013147:Spirometry; D016138:Walking
keywords: 6-minute walk test; Capacidad de ejercicio; Chronic obstructive pulmonary disease; Distance covered; Distancia recorrida; Enfermedad pulmonar obstructiva crónica; Exercise capacity; Positive expiratory pressure; Presión espiratoria positiva; Prueba de marcha de 6 min