title: Nebulized albuterol delivery in a model of spontaneously breathing children with tracheostomy.
abstract: BACKGROUND
  Nebulized therapy is commonly used in spontaneously breathing tracheostomized patients, despite a lack of recommended devices and techniques. I compared albuterol dose delivered to a model of spontaneously breathing children with tracheostomy, using different nebulizers, tracheostomy tube sizes, inhalation techniques, and breathing patterns.
  
  
  METHODS
  A tracheostomy model was connected in series to a breathing simulator, with a filter interposed. I simulated the breathing patterns of a 16-month-old child and 12-year-old child, and tested tracheostomy tubes with internal diameters of 3.5 mm and 5.5 mm. Albuterol nebulizer solution (2.5 mg/3 mL) was used. A breath-enhanced nebulizer (Pari LC Plus), a breath-actuated nebulizer (AeroEclipse), and a nebulizer that continuously delivers aerosol (Up-Draft II Opti-Neb) were operated for 5 min at 6 L/min with wall air. The Up-Draft II was tested with T-piece and mask interfaces, with an extension tube, and with and without assisted breathing (every breath and every other breath). The amount of albuterol delivered was analyzed via spectrophotometry. Particle size distribution was measured with a cascade impactor.
  
  
  RESULTS
  The Pari LC Plus was more efficient than the Up-Draft II or AeroEclipse. Assisted breathing with the Up-Draft II with extension increased albuterol delivery with every other breath (second best device/configuration), being superior to every breath technique. Adding an extension tube increased delivered albuterol. T-piece was more efficient than mask. Breathing patterns with larger tidal volume increased albuterol delivery. Tracheostomy size had less impact on drug delivery. Mass median aerodynamic diameter decreased by 48-74% when passing through the tracheostomy tubes, and 0.8% of the nominal dose was deposited in the tracheostomy tube.
  
  
  CONCLUSIONS
  Albuterol delivery in a model of spontaneously breathing children with tracheostomy is influenced by type of device and configuration, use of assisted breathing, breathing pattern, and tracheostomy tube size. Mass median aerodynamic diameter significantly decreases during passage through a tracheostomy tube.
authors.affiliation: Pulmonology Section, Department of Pediatrics, University of Arkansas for Medical Sciences, and with the Pediatric Aerosol Research Laboratory, Arkansas Children's Hospital Research Institute, Little Rock, Arkansas.
authors.forename: Ariel
authors.initials: A
authors.lastname: Berlinski
mesh_terms: D000280:Administration, Inhalation; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D002648:Child; D003198:Computer Simulation; D016503:Drug Delivery Systems / Q000145:classification / Q000295:instrumentation / Q000379:methods; D004867:Equipment Design; D006801:Humans; D008954:Models, Biological; D009330:Nebulizers and Vaporizers; D012119:Respiration / Q000187:drug effects; D014139:Tracheostomy / Q000295:instrumentation / Q000379:methods
chemical_list: D001993:Bronchodilator Agents
keywords: albuterol; children; delivery device; nebulizer; tracheostomy