title: Aerosol deposition in neonatal ventilation.
abstract: Lung deposition of inhaled drugs in ventilated neonates has been studied in models of questionable relevance. With conventional nebulizers, pulmonary deposition has been limited to 1% of the total dose. The objective of this study was to assess lung delivery of aerosols in a model of neonatal ventilation using a conventional and novel electronic micropump nebulizer. Aerosol deposition studies with 99mTc diethylenetriamine pentaacetate (99mTc-DTPA) were performed in four macaques (2.6 kg) that were ventilated through a 3.0-mm endotracheal tube (with neonatal settings (peak inspiratory pressure 12-14 mbar, positive end-expiratory pressure 2 mbar, I/E ratio 1/2, respiratory rate 40/min), comparing a jet-nebulizer MistyNeb (3-mL charge, 4.8 microm), an electronic micropump nebulizer operating continuously [Aeroneb Professional Nebulizer (APN-C); 0.5-mL charge, 4.6 microm], and another synchronized with inspiration [Aeroneb Professional Nebulizer Synchronized (APN-S); 0.5-mL charge, 2.8 microm]. The amount of radioactivity deposited into lungs and connections and remaining in the nebulizer was measured by a gamma counter. Despite similar amounts of 99mTc-DTPA in the respiratory circuit with all nebulizers, both APN-S and APN-C delivered more drug to the lungs than MistyNeb (14.0, 12.6, and 0.5% in terms of percentage of nebulizer charge, respectively; p = 0.006). Duration of delivery was shorter with APN-C than with the two other nebulizers (2 versus 6 and 10 min for the APN-S and the MistyNeb, respectively; p < 0.001). Electronic micropump nebulizers are more efficient to administer aerosols in an animal model of ventilated neonates. Availability of Aerogen's electronic micropump nebulizers offers new opportunities to study clinical efficacy and risks of aerosol therapy in ventilated neonates.
authors.affiliation: INSERM U618, Service de Pneumologie, CHU Bretonneau, 2 Boulevard Tonnellé, 37044 Tours, France.
authors.forename: Jean C
authors.initials: JC
authors.lastname: Dubus
authors.forename: Laurent
authors.initials: L
authors.lastname: Vecellio
authors.forename: Michele
authors.initials: M
authors.lastname: De Monte
authors.forename: James B
authors.initials: JB
authors.lastname: Fink
authors.forename: Daniel
authors.initials: D
authors.lastname: Grimbert
authors.forename: Jerome
authors.initials: J
authors.lastname: Montharu
authors.forename: Chantal
authors.initials: C
authors.lastname: Valat
authors.forename: Neil
authors.initials: N
authors.lastname: Behan
authors.forename: Patrice
authors.initials: P
authors.lastname: Diot
mesh_terms: D000280:Administration, Inhalation; D000336:Aerosols / Q000378:metabolism*; D000818:Animals; D004867:Equipment Design; D005260:Female; D015902:Gamma Cameras; D008168:Lung / Q000473:pathology; D008171:Lung Diseases / Q000473:pathology*; D008251:Macaca; D008297:Male; D009330:Nebulizers and Vaporizers; D011014:Pneumonia; D011877:Radionuclide Imaging; D012119:Respiration; D012121:Respiration, Artificial / Q000379:methods; D012138:Respiratory Therapy; D016284:Technetium Tc 99m Pentetate / Q000737:chemistry; D014132:Trachea / Q000378:metabolism; D012122:Ventilators, Mechanical
chemical_list: D000336:Aerosols; D016284:Technetium Tc 99m Pentetate