title: Aerosol delivery and humidification with the Boussignac continuous positive airway pressure device.
abstract: BACKGROUND
  A simple method for effective bronchodilator aerosol delivery while administering continuing continuous positive airway pressure (CPAP) would be useful in patients with severe bronchial obstruction.
  
  
  OBJECTIVE
  To assess the effectiveness of bronchodilator aerosol delivery  during CPAP generated by the Boussignac CPAP system and its optimal humidification system.
  
  
  METHODS
  First we assessed the relationship between flow and pressure generated in the mask with the Boussignac CPAP system. Next we measured the inspired-gas humidity during CPAP, with several humidification  strategies, in 9 healthy volunteers. We then measured the bronchodilator aerosol particle size during CPAP, with and without heat-and-moisture exchanger, in a bench study. Finally, in 7 patients with acute respiratory failure and airway obstruction, we measured work of breathing and gas exchange  after a β(2)-agonist bronchodilator aerosol (terbutaline) delivered during CPAP or via standard nebulization.
  
  
  RESULTS
  Optimal humidity was obtained only with the heat-and-moisture exchanger or heated humidifier. The heat-and-moisture exchanger had no influence on bronchodilator  aerosol particle size. Work of breathing decreased similarly after bronchodilator via either standard nebulization or CPAP, but P(aO(2)) increased significantly only after CPAP aerosol delivery.
  
  
  CONCLUSIONS
  CPAP bronchodilator delivery decreases the work of breathing as  effectively as does standard nebulization, but produces a greater oxygenation improvement in patients with airway obstruction. To optimize airway humidification, a heat-and-moisture exchanger could be used with the Boussignac CPAP system, without modifying aerosol delivery.
authors.affiliation: Medical Intensive Care Unit, Assistance Publique- Hôpitaux de Paris, Henri Mondor Hospital, University of Paris Est, Créteil, France. arnaud.thille@hmm.aphp.fr
authors.forename: Arnaud W
authors.initials: AW
authors.lastname: Thille
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Bertholon
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Becquemin
authors.forename: Monique
authors.initials: M
authors.lastname: Roy
authors.forename: Aissam
authors.initials: A
authors.lastname: Lyazidi
authors.forename: François
authors.initials: F
authors.lastname: Lellouche
authors.forename: Esther
authors.initials: E
authors.lastname: Pertusini
authors.forename: Georges
authors.initials: G
authors.lastname: Boussignac
authors.forename: Bernard
authors.initials: B
authors.lastname: Maître
authors.forename: Laurent
authors.initials: L
authors.lastname: Brochard
mesh_terms: D058666:Adrenergic beta-2 Receptor Agonists / Q000008:administration & dosage; D000336:Aerosols / Q000008:administration & dosage; D001982:Bronchial Diseases / Q000503:physiopathology / Q000628:therapy*; D001993:Bronchodilator Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D045422:Continuous Positive Airway Pressure / Q000295:instrumentation*; D006801:Humans; D006813:Humidity; D010316:Particle Size; D011659:Pulmonary Gas Exchange; D013726:Terbutaline / Q000008:administration & dosage; D014939:Work of Breathing
chemical_list: D058666:Adrenergic beta-2 Receptor Agonists; D000336:Aerosols; D001993:Bronchodilator Agents; D013726:Terbutaline