title: In vitro evaluation of aerosol delivery by different nebulization modes in pediatric and adult mechanical ventilators.
abstract: BACKGROUND
  Aerosol delivery through mechanical ventilation is influenced by the type of aerosol generator, pattern of nebulization, and a patient's breathing pattern. This study compares the efficiency of pneumatic nebulization modes provided by a ventilator with adult and pediatric in vitro lung models.
  
  
  METHODS
  Three pneumatic nebulization modes (inspiratory intermittent [IIM], continuous [CM], and expiratory intermittent [EIM]) provided by the Galileo Gold ventilator delivered medical aerosol to collection filters distal to an endotracheal tube with adult and pediatric test lungs. A unit dose of 5 mg/2.5 mL albuterol was diluted into 4 mL with distilled water and added to a jet nebulizer. The nebulizer was placed proximal to the ventilator, 15 cm from the inlet of the heated humidifier chamber with a T-piece and corrugated aerosol tubing and powered by gas from the ventilator in each of the 3 modes. Time for nebulization was recorded in minutes. Albuterol samples collected in the inhalation filter, nebulizer, T-piece, and corrugated tubing were eluted with distilled water and analyzed with a spectrophotometer.
  
  
  RESULTS
  The inhaled drug, as a percentage of total dose in both lung models, was 5.1-7.5%, without statistical significance among the 3 modes. Median nebulization times for IIM, CM, and EIM were 38.9, 14.3, and 17.7 min, respectively, and nebulization time for the 3 modes significantly differed (P < .001). The inhaled drug mass for the 3 modes with the adult lung model was similar to that with the pediatric lung model (7.39 ± 0.76 vs. 6.27 ± 0.69%, P = .77).
  
  
  CONCLUSIONS
  Aerosol drug delivery with a jet nebulizer placed proximal to the ventilator was not dependent on nebulization mode during simulated pediatric and adult conventional mechanical ventilation. Use of expiratory intermittent mode and continuous nebulization should be considered to reduce treatment time.
authors.affiliation: Department of Respiratory Therapy, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Gwo-Hwa
authors.initials: GH
authors.lastname: Wan
authors.affiliation: Department of Respiratory Therapy, College of Medicine, Chang Gung University, Taoyuan, Taiwan. 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: James B
authors.initials: JB
authors.lastname: Fink
authors.affiliation: Department of Respiratory Therapy, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Yen-Hey
authors.initials: YH
authors.lastname: Chen
authors.affiliation: Department of Respiratory Therapy, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Wei-Jhen
authors.initials: WJ
authors.lastname: Wang
authors.affiliation: Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Yu-Chun
authors.initials: YC
authors.lastname: Chiu
authors.affiliation: Department of Respiratory Therapy, Chang Gung Memorial Hospital-Linko Branch, Taoyuan, Taiwan.
authors.forename: Yu-Yao
authors.initials: YY
authors.lastname: Kao
authors.affiliation: Department of Respiratory Therapy, Chang Gung Memorial Hospital-Linko Branch, Taoyuan, Taiwan.
authors.forename: Chia-Jung
authors.initials: CJ
authors.lastname: Liu
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D000336:Aerosols / Q000008:administration & dosage*; D000420:Albuterol / Q000008:administration & dosage*; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D002648:Child; D016503:Drug Delivery Systems; D004867:Equipment Design; D005374:Filtration; D006801:Humans; D066298:In Vitro Techniques; D007442:Intubation, Intratracheal; D009330:Nebulizers and Vaporizers; D010372:Pediatrics / Q000295:instrumentation; D012121:Respiration, Artificial / Q000295:instrumentation*; D013997:Time Factors
chemical_list: D000336:Aerosols; D001993:Bronchodilator Agents; D000420:Albuterol
keywords: aerosol drug delivery; bronchodilator; endotracheal tube; mechanical ventilation; nebulization mode; small-volume nebulizer