title: Intrinsic positive end-expiratory pressure at various frequencies of supraglottic jet ventilation in a model of dynamic upper airway obstruction.
abstract: BACKGROUND
  Supraglottic jet ventilation (JV(S)) with injectors above airway stenoses may result in inadvertent high lung pressures. We designed this study to investigate intrinsic positive end-expiratory pressure (PEEP(i)) during jet ventilation via a distant injector in a model of dynamic upper airway obstruction.
  
  
  METHODS
  Respiratory pressure-time curves were recorded during JV(S) in a tracheal lung model using a pig's trachea and an embolectomy catheter's air-filled balloon to simulate 60 and 80% airway obstruction. JV(S) was performed at various jet frequencies (F(jet) 30 min(-1), 60 min(-1), and 100 min(-1)) and driving pressures (1 bar and 2 bar).
  
  
  RESULTS
  JV(S) was associated with generation of PEEP(i), which depended on driving pressure, the degree of obstruction, and on ventilatory frequency.
  
  
  CONCLUSIONS
  In the presence of a dynamic upper airway obstruction, JV(S) via a distant injector may result in PEEP(i), which cannot be detected when airway pressure is measured in front of the obstruction.
authors.affiliation: Department of Anesthesia, Intensive Care Medicine and Pain Therapy, Medical University Vienna, Waehringer Guertel 18-20, AKH 9i, A-1090 Vienna, Austria. gerald.ihra@meduniwien.ac.a
authors.forename: Gerald C
authors.initials: GC
authors.lastname: Ihra
authors.forename: Ching-Ju
authors.initials: CJ
authors.lastname: Tsai
authors.forename: Oliver
authors.initials: O
authors.lastname: Kimberger
mesh_terms: D000402:Airway Obstruction / Q000628:therapy*; D000818:Animals; D017128:Embolectomy; D006611:High-Frequency Jet Ventilation; D008953:Models, Anatomic; D011175:Positive-Pressure Respiration; D013552:Swine; D014133:Tracheal Diseases / Q000628:therapy