title: The effects of Heliox on the output and particle-size distribution of salbutamol using jet and vibrating mesh nebulizers.
abstract: There are theoretical benefits of delivering drug aerosols to patients with asthma and chronic obstructive pulmonary disease (COPD) using Heliox as a carrier gas. The objective of this study was to develop systems to allow bronchodilators nebulized by a breath enhanced jet nebulizer and a vibrating mesh nebulizer to be delivered to patients in Heliox. This was achieved by attaching a reservoir to the nebulizers to ensure inhaled Heliox was not diluted by entrained air. For the vibrating mesh nebulizer, the total output was significantly higher after 5 min of nebulization when Heliox rather than air was used as the delivery gas (p < 0.001). The proportion of drug in particles <5 microm was 58.1% for Heliox and 50.1% when air was entrained. When the breath enhanced nebulizer was used a much higher driving flow of Heliox, compared to air, was required to deliver a similar dose of drug (p < 0.05). The total amount of drug likely to be inhaled was significantly higher when the vibrating mesh nebulizer (Aerogen) was used compared to the breath enhanced jet nebulizer (Pari LC plus) (p < 0.001). The amount of drug likely to be inhaled was also significantly greater for the adult as opposed to pediatric breathing pattern for all nebulizers and flows tested with the exception of the Aeroneb and Heliox entrainment. In this case, total amounts were similar for both patterns but for the pediatric pattern, the time taken to reach this output was longer. Such information is required to allow appropriate interpretation of clinical trials of drug delivery using Heliox.
authors.affiliation: Department of Infection, Immunity and Inflammation, Division of Child Health, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom. ajb64@le.ac.uk
authors.forename: Christopher
authors.initials: C
authors.lastname: O'Callaghan
authors.forename: Judy
authors.initials: J
authors.lastname: White
authors.forename: Judith
authors.initials: J
authors.lastname: Jackson
authors.forename: David
authors.initials: D
authors.lastname: Crosby
authors.forename: Beatriz
authors.initials: B
authors.lastname: Dougill
authors.forename: Hubert
authors.initials: H
authors.lastname: Bland
mesh_terms: D000280:Administration, Inhalation; D000420:Albuterol / Q000008:administration & dosage*; D001249:Asthma / Q000188:drug therapy; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D004337:Drug Carriers; D004867:Equipment Design; D005740:Gases / Q000008:administration & dosage*; D006371:Helium / Q000008:administration & dosage*; D006801:Humans; D009330:Nebulizers and Vaporizers; D010100:Oxygen / Q000008:administration & dosage*; D010316:Particle Size; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy; D014732:Vibration
chemical_list: D001993:Bronchodilator Agents; D004337:Drug Carriers; D005740:Gases; D006371:Helium; C038949:heliox; D000420:Albuterol; D010100:Oxygen