title: CPAP has no effect on clearance, sputum properties, or expectorated volume in cystic fibrosis.
abstract: BACKGROUND
  Positive expiratory pressure (PEP) is used for airway clearance in cystic fibrosis (CF) patients. Hypertonic saline (HTS) aerosol increases sputum expectoration volume and may improve respiratory secretion properties. CPAP may also be used to maintain airway patency and  mobilize secretions. To evaluate if CPAP would increase the beneficial clearance effect of HTS in subjects with CF, we investigated the effects of CPAP alone and CPAP followed by HTS on sputum physical properties and expectoration volume in CF subjects.
  
  
  METHODS
  In this crossover study, 15  CF subjects (mean age 19 y old) were randomized to interventions, 48 hours apart: directed coughs (control), CPAP at 10 cm H(2)O, HTS 7%, and both CPAP and HTS (CPAP+HTS). Sputum collection was performed at baseline and after interventions. Expectorated volume was determined and in  vitro sputum properties were analyzed for contact angle and cough clearability.
  
  
  RESULTS
  There were no significant differences between any treatment in arterial blood pressure, heart rate, or pulse oximetry, between the 2 time points. HTS and CPAP+HTS improved cough clearability by 50% (P  = .001) and expectorated volume secretion by 530% (P = .001). However, there were no differences between control and CPAP on sputum contact angle, cough clearability, or volume of expectorated secretion.
  
  
  CONCLUSIONS
  CPAP alone had no effect on mucus clearance, sputum properties, or  expectorated volume, and did not potentiate the effect of HTS alone in CF subjects.
authors.affiliation: Hospital Infantil João Paulo II, Universidade Católica de Minas Gerais, Minas Gerais, Brazil.
authors.forename: Evanirso Silva
authors.initials: ES
authors.lastname: Aquino
authors.forename: Francine
authors.initials: F
authors.lastname: Shimura
authors.forename: Adriana Silveira
authors.initials: AS
authors.lastname: Santos
authors.forename: Danielle Miyuki
authors.initials: DM
authors.lastname: Goto
authors.forename: Cristiane Cenachi
authors.initials: CC
authors.lastname: Coelho
authors.forename: Marcelo Bicalho
authors.initials: MB
authors.lastname: de Fuccio
authors.forename: Paulo Hilario Nascimento
authors.initials: PH
authors.lastname: Saldiva
authors.forename: Geraldo
authors.initials: G
authors.lastname: Lorenzi-Filho
authors.forename: Bruce K
authors.initials: BK
authors.lastname: Rubin
authors.forename: Naomi Kondo
authors.initials: NK
authors.lastname: Nakagawa
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D002648:Child; D045422:Continuous Positive Airway Pressure; D003371:Cough; D018592:Cross-Over Studies; D003550:Cystic Fibrosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D009079:Mucociliary Clearance / Q000502:physiology*; D012129:Respiratory Function Tests; D013183:Sputum / Q000502:physiology*; D016896:Treatment Outcome