title: In Vitro Comparison of Aerosol Delivery Using Different Face Masks and Flow Rates With a High-Flow Humidity System.
abstract: BACKGROUND
  Aerosol drug delivery to infants and small children is influenced by many factors, such as types of interface, gas flows, and the designs of face masks. The purpose of this in vitro study was to evaluate aerosol delivery during administration of gas flows across the range used clinically with high-flow humidity systems using 2 aerosol masks.
  
  
  METHODS
  A spontaneous lung model was used to simulate an infant/young toddler up to 2 y of age and pediatric breathing patterns. Nebulized salbutamol by a vibrating mesh nebulizer positioned at the inlet of a high-flow humidification system at gas flows of 3, 6, and 12 L/min was delivered via pediatric face masks to a pediatric face mannequin attached to a filter. Aerosol particle size distribution exiting the vibrating mesh nebulizer and at the mask position distal to the heated humidifier with 3 flows was measured with a cascade impactor. Eluted drug from the filters and the impactor was analyzed with a spectrophotometer (n = 3). Statistical analysis was performed by analysis of variance with a significant level of P < .05.
  
  
  RESULTS
  The inhaled mass was between 2.8% and 8.1% among all settings and was significantly lower at 12 L/min (P = .004) in the pediatric model. Drug delivery with pediatric breathing was greater than with infant breathing (P = .004). The particle size distribution of aerosol emitted from the nebulizer was larger than the heated humidified aerosol exiting the tubing (P = .002), with no difference between the 3 flows (P = .10).
  
  
  CONCLUSIONS
  The flows of gas entering the mask and breathing patterns influence aerosol delivery, independent of the face mask used. Aerosol delivery through a high-flow humidification system via mask could be effective with both infant and pediatric breathing patterns.
authors.affiliation: Respiratory Therapy Program, College of Medicine, Chang Gung University, Taoyuan, Taiwan, Republic of China. huilingrrt@gmail.com.
authors.forename: Hui-Ling
authors.initials: HL
authors.lastname: Lin
authors.affiliation: Division of Respiratory Therapy, Georgia State University, Atlanta, Georgia.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Harwood
authors.affiliation: Division of Respiratory Therapy, Georgia State University, Atlanta, Georgia. James B Fink LLC, San Mateo, California.
authors.forename: James B
authors.initials: JB
authors.lastname: Fink
authors.affiliation: Division of Respiratory Therapy, Georgia State University, Atlanta, Georgia.
authors.forename: Lynda T
authors.initials: LT
authors.lastname: Goodfellow
authors.affiliation: Division of Respiratory Therapy, Georgia State University, Atlanta, Georgia.
authors.forename: Arzu
authors.initials: A
authors.lastname: Ari
mesh_terms: D000280:Administration, Inhalation; D000336:Aerosols; D000420:Albuterol / Q000008:administration & dosage*; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D002675:Child, Preschool; D004867:Equipment Design; D006801:Humans; D006813:Humidity; D007223:Infant; D008168:Lung; D008397:Masks; D008953:Models, Anatomic; D009330:Nebulizers and Vaporizers; D012138:Respiratory Therapy / Q000295:instrumentation*
chemical_list: D000336:Aerosols; D001993:Bronchodilator Agents; D000420:Albuterol
keywords: aerosol delivery; aerosol mask; gas flows; high-flow humidification; particle size distribution; pediatric; vibrating mesh nebulizer