title: Aerosol delivery during high frequency jet ventilation: an MRI evaluation.
abstract: BACKGROUND
  We have previously demonstrated aerosol delivery during conventional and high frequency oscillatory (HFOV) ventilation using magnetic resonance imaging (MRI) in piglets. There are no reports on aerosol delivery during high frequency jet ventilation (HFJV).
  
  
  OBJECTIVE
  To  compare delivery of aerosolized gadopentetate dimeglumine (Gd-DTPA) in 3 neonatal ventilator circuits: conventional mechanical ventilation, HFOV, and HFJV.
  
  
  METHODS
  Aerosols of Gd-DTPA (0.025 mol/L) generated using a jet nebulizer placed in the inspiratory limb of each ventilator were delivered  into an in vitro lung model simultaneously. Multi-slice T1-weighted spin-echo sequence scans were obtained prior to and after 10 and 20 min of cumulative aerosol delivery. Gd-DTPA concentration was calculated from signal intensity changes, and the total amount of Gd-DTPA was estimated.
  
  
  RESULTS
  Gd-DTPA was visualized in the lung model at 10 and 20 min for all 3 ventilators. Gd-DTPA delivery was highest with conventional mechanical ventilation (1.92 μmol at 10 min, 2.89 μmol at 20 min), followed by HFJV (1.59 μmol at 10 min, 1.98 μmol at 20 min) and HFOV (0.79 μmol  at 10 min, 1.00 μmol at 20 min).
  
  
  CONCLUSIONS
  This is the first report of effective aerosol delivery in a neonatal HFJV circuit. Future studies are needed for more accurate quantification of aerosol deposition.
authors.affiliation: Department of Pediatrics, Children's Hospital of Michigan, Detroit, MI 48201, USA. bsood@med.wayne.edu
authors.forename: Beena G
authors.initials: BG
authors.lastname: Sood
authors.forename: Zahid
authors.initials: Z
authors.lastname: Latif
authors.forename: Yimin
authors.initials: Y
authors.lastname: Shen
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Galli
authors.forename: Charles W
authors.initials: CW
authors.lastname: Dunlap
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Gelmini
authors.forename: E Mark
authors.initials: EM
authors.lastname: Haacke
mesh_terms: D000280:Administration, Inhalation; D000336:Aerosols / Q000008:administration & dosage*; D003287:Contrast Media / Q000008:administration & dosage; D019786:Gadolinium DTPA / Q000008:administration & dosage; D006611:High-Frequency Jet Ventilation; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008953:Models, Anatomic
chemical_list: D000336:Aerosols; D003287:Contrast Media; D019786:Gadolinium DTPA