title: Adapting the Bird Mark 7 to deliver noninvasive continuous positive airway pressure: a bench study.
abstract: OBJECTIVE
  To test the efficiency of the Bird Mark 7 ventilator adapted to deliver continuous positive airway pressure (CPAP) in noninvasive positive pressure ventilation.
  
  
  METHODS
  This was an experimental study using a mechanical model of the respiratory system. A Bird Mark 7 ventilator was supplied with 400 and 500 kPa and tested at CPAP of 5, 10 and 15 cmH2O. The following variables were analyzed: difference between the preset CPAP and the CPAP actually attained CPAP (trueCPAP); area of airway pressure at the CPAP level employed (AREA CPAP); and tidal volume generated.
  
  
  RESULTS
  Adapting the Bird Mark 7 to offer CPAP achieved the expected tidal volume in all situations of inspiratory effort (normal or high), ventilator pressure supply (400 or 500 kPa) and CPAP value (5, 10 or 15 cmH2O). At a CPAP of 5 or 10 cmH2O, the trueCPAP was near the preset level, and the AREA CPAP was near zero. However, at a CPAP of 15 cmH2O, the value remained below the preset, and the AREA CPAP was high.
  
  
  CONCLUSIONS
  The efficiency of Bird Mark 7 adaptation in offering CPAP was satisfactory at 5 and 10 cmH2O but insufficient at 15 cmH2O. If adapted as described in our study, the Bird Mark 7 might be an option for offering CPAP up to 10 cmH2O in areas where little or no equipment is available.
authors.affiliation: University of São Paulo School of Medicine, São Paulo, Brazil.
authors.forename: Beatriz Mayumi
authors.initials: BM
authors.lastname: Kikuti
authors.forename: Karen
authors.initials: K
authors.lastname: Utsunomia
authors.forename: Renata Potonyacz
authors.initials: RP
authors.lastname: Colaneri
authors.forename: Carlos Roberto Ribeiro de
authors.initials: CR
authors.lastname: Carvalho
authors.forename: Pedro
authors.initials: P
authors.lastname: Caruso
mesh_terms: D045422:Continuous Positive Airway Pressure / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D006801:Humans; D015656:Respiratory Mechanics / Q000502:physiology*; D012122:Ventilators, Mechanical / Q000592:standards*; D014939:Work of Breathing / Q000502:physiology