title: Radioaerosol Pulmonary Deposition Using Mesh and Jet Nebulizers During Noninvasive Ventilation in Healthy Subjects.
abstract: BACKGROUND
  In vivo deposition studies of aerosol administration during noninvasive ventilation (NIV) are scarce in the literature. The aim of this study was to compare radioaerosol pulmonary index and radioaerosol mass balance in the different compartments (pulmonary and extrapulmonary) of radio-tagged aerosol administered using vibrating mesh nebulizers and conventional jet nebulizers during NIV.
  
  
  METHODS
  This was a crossover clinical trial involving 10 healthy subjects (mean age of 33.7 ± 10.0 y) randomly assigned to both treatment arms of this study: group 1 (NIV + vibrating mesh nebulizer, n = 10) and group 2 (NIV + jet nebulizer, n = 10). All subjects inhaled 3 mL of technetium-99m diethylenetriaminepentaacetic acid (25 mCi) and 0.9% saline solution via vibrating mesh and jet nebulizers during NIV through a face mask secured with straps while receiving positive inspiratory and expiratory pressures of 12 and 5 cm H2O, respectively. Scintigraphy was performed to count radioaerosol particles deposited in the regions of interest to determine radioaerosol mass balance from the lungs, upper airways, stomach, nebulizer, ventilator circuit, inspiratory and expiratory filters, and mask as a percentage.
  
  
  RESULTS
  Vibrating mesh nebulizers deposited 972,013 ± 214,459 counts versus jet nebulizer with 386,025 ± 130,363 counts (P = .005). In a determination of mass balance, vibrating mesh nebulizers showed a higher deposition of inhaled radioaerosol compared with jet nebulizers (23.1 ± 5.8% vs 6.1 ± 2.5%, P = .005) and a higher proportion of radioaerosol deposited into the lungs (5.5 ± 0.9% versus 1.5 ± 0.6%, respectively, P = .005). The residual drug volume was lower with vibrating mesh nebulizers (5.1 ± 1.5%) compared with jet nebulizers (41.3 ± 4.2%, P = .005).
  
  
  CONCLUSIONS
  During NIV in healthy subjects, vibrating mesh nebulizers delivered > 2-fold more radiolabeled drug into the respiratory tract compared with conventional jet nebulizers. Additional studies are recommended in subjects with asthma, COPD, bronchiectasis, and cystic fibrosis to better understand differences in both aerosol delivery and response. (ClinicalTrials.gov registration NCT01889524.).
authors.affiliation: Department of Physical Therapy, Universidade Federal de Pernambuco, Recife City, Pernambuco, Brazil. vcastorgalindo@yahoo.com.
authors.forename: Valdecir C
authors.initials: VC
authors.lastname: Galindo-Filho
authors.affiliation: Department of Physical Therapy, Universidade Federal de Pernambuco, Recife City, Pernambuco, Brazil.
authors.forename: Maria Eveline
authors.initials: ME
authors.lastname: Ramos
authors.affiliation: Department of Physical Therapy, Universidade Federal de Pernambuco, Recife City, Pernambuco, Brazil.
authors.forename: Catarina S F
authors.initials: CS
authors.lastname: Rattes
authors.affiliation: Department of Nuclear Medicine, Hospital das Clínicas de Pernambuco, Recife City, Pernambuco, Brazil.
authors.forename: Antônio K
authors.initials: AK
authors.lastname: Barbosa
authors.affiliation: Department of Physical Therapy, Universidade Federal de Pernambuco, Recife City, Pernambuco, Brazil.
authors.forename: Daniella C
authors.initials: DC
authors.lastname: Brandão
authors.affiliation: Department of Nuclear Medicine, Hospital das Clínicas de Pernambuco, Recife City, Pernambuco, Brazil.
authors.forename: Simone Cristina S
authors.initials: SC
authors.lastname: Brandão
authors.affiliation: Division of Respiratory Therapy, School of Health Professions, Georgia State University, Atlanta, Georgia, Rush University Medical Center, Chicago, Illinois, and James B Fink LLC, San Mateo, California.
authors.forename: James B
authors.initials: JB
authors.lastname: Fink
authors.affiliation: Department of Physical Therapy, Universidade Federal de Pernambuco, Recife City, Pernambuco, Brazil.
authors.forename: Armèle Dornelas
authors.initials: AD
authors.lastname: de Andrade
mesh_terms: D000328:Adult; D000336:Aerosols; D018592:Cross-Over Studies; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008168:Lung / Q000187:drug effects; D008297:Male; D009330:Nebulizers and Vaporizers; D063087:Noninvasive Ventilation / Q000295:instrumentation* / Q000379:methods; D019275:Radiopharmaceuticals / Q000008:administration & dosage*; D016284:Technetium Tc 99m Pentetate / Q000008:administration & dosage*
chemical_list: D000336:Aerosols; D019275:Radiopharmaceuticals; D016284:Technetium Tc 99m Pentetate
keywords: aerosol; inhalation device; nebulizer; noninvasive ventilation; pulmonary scintigraphy; radioaerosol