title: Oronasal and Tracheostomy Delivery of Soft Mist and Pressurized Metered-Dose Inhalers With Valved Holding Chamber.
abstract: BACKGROUND
  Some pediatric tracheostomized patients who receive inhaled drugs undergo decannulation, and it is unknown whether the dose has to be adjusted. Pressurized metered-dose inhalers (pMDIs) and soft mist inhalers (SMIs) used with valved holding chambers (VHCs) made of non-electrostatic material are available. We hypothesized that using an SMI and changing the delivery route from tracheostomy to oronasal would increase lung dose.
  
  
  METHODS
  Four units of a metallic VHC were studied with albuterol hydrofluoroalkane (pMDI) and albuterol/ipratropium bromide with an SMI using an anatomically correct in vitro model of a 5-y-old spontaneously breathing tracheostomized child. The drug was captured in a filter and was termed lung dose. We tested breathing patterns with tidal volumes of 50, 155, and 300 mL. A mask and a special adapter were used as interfaces for oronasal and tracheostomy delivery, respectively. Spectrophotometry (276 nm) was used to determine albuterol concentration.
  
  
  RESULTS
  The use of SMI resulted in a higher lung dose than the pMDI for all tested conditions except delivery through tracheostomy with tidal volume of 155 mL (P = .69). Switching from oronasal to tracheostomy delivery increased the lung dose for all tested conditions except for the pMDI with the 300-mL tidal volume (P = .83). The use of SMI resulted in higher deposition in the tracheostomy tube than the pMDI.
  
  
  CONCLUSIONS
  In general, an SMI delivers a higher lung dose than a pMDI when using a metallic spacer during oronasal and tracheostomy route with the latter providing a higher lung dose.
authors.affiliation: Pulmonology Section, Department of Pediatrics, University of Arkansas for Medical Sciences and the Pediatric Aerosol Research Laboratory, Arkansas Children's Hospital Research Institute, Little Rock, Arkansas. BerlinskiAriel@uams.edu.
authors.forename: Ariel
authors.initials: A
authors.lastname: Berlinski
authors.affiliation: College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, Arkansas.
authors.forename: Brandy
authors.initials: B
authors.lastname: Cooper
mesh_terms: D000280:Administration, Inhalation; D000336:Aerosols / Q000008:administration & dosage*; D000420:Albuterol / Q000008:administration & dosage; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D002675:Child, Preschool; D058868:Compressed Air; D016503:Drug Delivery Systems / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D006801:Humans; D036503:Inhalation Spacers; D008168:Lung; D008397:Masks; D036501:Metered Dose Inhalers; D008953:Models, Anatomic; D009330:Nebulizers and Vaporizers; D014139:Tracheostomy
chemical_list: D000336:Aerosols; D001993:Bronchodilator Agents; D000420:Albuterol
keywords: Respimat; aerosol; artificial airway; drug delivery; metered dose inhaler; pediatrics; soft mist inhaler; tracheostomy; valved holding chamber