title: Effects of ventilator settings, nebulizer and exhalation port position on albuterol delivery during non-invasive ventilation: an in-vitro study.
abstract: Few studies have investigated the factors affecting aerosol delivery during non-invasive ventilation (NIV). Our aim was to investigate, using a bench-top model, the effect of different ventilator settings and positions of the exhalation port and nebulizer on the amount of albuterol delivered to a lung simulator.
  
  
  
  A lung model simulating spontaneous breathing was connected to a single-limb NIV ventilator, set in bi-level positive airway pressure (BIPAP) with inspiratory/expiratory pressures of 10/5, 15/10, 15/5, and 20/10 cmH2O, or continuous positive airway pressure (CPAP) of 5 and 10 cmH2O. Three delivery circuits were tested: a vented mask with the nebulizer directly connected to the mask, and an unvented mask with a leak port placed before and after the nebulizer. Albuterol was collected on a filter placed after the mask and then the delivered amount was measured with infrared spectrophotometry.
  
  
  
  Albuterol delivery during NIV varied between 6.7 ± 0.4% to 37.0 ± 4.3% of the nominal dose. The amount delivered in CPAP and BIPAP modes was similar (22.1 ± 10.1 vs. 24.0 ± 10.0%, p = 0.070). CPAP level did not affect delivery (p = 0.056); in BIPAP with 15/5 cmH2O pressure the delivery was higher compared to 10/5 cmH2O (p = 0.033) and 20/10 cmH2O (p = 0.014). Leak port position had a major effect on delivery in both CPAP and BIPAP, the best performances were obtained with the unvented mask, and the nebulizer placed between the leak port and the mask (p < 0.001).
  
  
  
  In this model, albuterol delivery was marginally affected by ventilatory settings in NIV, while position of the leak port had a major effect. Nebulizers should be placed between an unvented mask and the leak port in order to maximize aerosol delivery.
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: 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.identifier: 0000-0002-3876-4730
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.|Dipartimento di Anestesia, Rianimazione e Terapia Intensiva, 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.|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.|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: Federico
authors.initials: F
authors.lastname: Costantino
authors.affiliation: Department of Chemistry and Industrial Chemistry, University of Genoa, Genoa, Italy.|SPIN-CNR, Genoa, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Ferretti
authors.affiliation: Department of Anesthesiology, Harvard Medical school, Department of Anesthesiology, Critical Care and Pain Medicine, and the Department of Respiratory Care, Massachusetts General Hospital, Boston, Massachusetts, USA.
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; D000420:Albuterol / Q000008:administration & dosage*; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D045422:Continuous Positive Airway Pressure; D006801:Humans; D008168:Lung; D008954:Models, Biological; D009330:Nebulizers and Vaporizers; D063087:Noninvasive Ventilation / Q000295:instrumentation*; D012122:Ventilators, Mechanical
chemical_list: D001993:Bronchodilator Agents; D000420:Albuterol
keywords: Aerosol; Albuterol; BIPAP; Bronchodilators; CPAP; Continuous positive airway pressure; NIV; Nebulizers