title: Effects of Nebulizer Position, Gas Flow, and CPAP on Aerosol Bronchodilator Delivery: An In Vitro Study.
abstract: BACKGROUND
  The aim of this study was to investigate the effects of different delivery circuit configurations, nebulizer positions, CPAP levels, and gas flow on the amount of aerosol bronchodilator delivered during simulated spontaneous breathing in an in vitro model.
  
  
  METHODS
  A pneumatic lung simulator was connected to 5 different circuits for aerosol delivery, 2 delivering CPAP through a high-flow generator tested at 30, 60, and 90 L/min supplementary flow and 5, 10, and 15 cm H2O CPAP and 3 with no CPAP: a T-piece configuration with one extremity closed with a cap, a T-piece configuration without cap and nebulizer positioned proximally, and a T-piece configuration without cap and nebulizer positioned distally. Albuterol was collected with a filter, and the percentage amount delivered was measured by infrared spectrophotometry.
  
  
  RESULTS
  Configurations with continuous high-flow CPAP delivered higher percentage amounts of albuterol compared with the configurations without CPAP (9.1 ± 6.0% vs 6.2 ± 2.8%, P = .03). Among configurations without CPAP, the best performance was obtained with a T-piece with one extremity closed with a cap. In CPAP configurations, the highest delivery (13.8 ± 4.4%) was obtained with the nebulizer placed proximal to the lung simulator, independent of flow. CPAP at 15 cm H2O resulted in the highest albuterol delivery (P = .02).
  
  
  CONCLUSIONS
  Based on our in vitro study, without CPAP, a T-piece with a cap at one extremity maximizes albuterol delivery. During high-flow CPAP, the nebulizer should always be placed proximal to the patient, after the T-piece, using the highest CPAP clinically indicated.
authors.affiliation: IRCCS AOU San Martino-IST, Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy. lorenzo.ball@edu.unige.it.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Ball
authors.affiliation: IRCCS AOU San Martino-IST, Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy. Division of Pulmonary and Critical Care Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Yuda
authors.initials: Y
authors.lastname: Sutherasan
authors.affiliation: Department of Chemistry and Industrial Chemistry, University of Genoa, Genoa, Italy and SPIN-CNR, Genoa, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Caratto
authors.affiliation: Department of Chemistry and Industrial Chemistry, University of Genoa, Genoa, Italy and SPIN-CNR, Genoa, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Sanguineti
authors.affiliation: IRCCS AOU San Martino-IST, Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Marsili
authors.affiliation: IRCCS AOU San Martino-IST, Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy. Department of Anesthesiology, Resuscitation, and Intensive Care, Università degli Studi di Foggia, Foggia, Italy.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Raimondo
authors.affiliation: Department of Chemistry and Industrial Chemistry, University of Genoa, Genoa, Italy and SPIN-CNR, Genoa, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Ferretti
authors.affiliation: Department of Anesthesiology and Critical Care and the Department of Respiratory Care, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Kacmarek
authors.affiliation: IRCCS AOU San Martino-IST, Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Pelosi
mesh_terms: D000280:Administration, Inhalation; D000336:Aerosols; D000420:Albuterol / Q000008:administration & dosage*; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D045422:Continuous Positive Airway Pressure / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D006801:Humans; D008953:Models, Anatomic; D009330:Nebulizers and Vaporizers; D056888:Patient Positioning
chemical_list: D000336:Aerosols; D001993:Bronchodilator Agents; D000420:Albuterol
keywords: aerosol; albuterol; bronchodilators; continuous positive airway pressure; cpap; nebulizers