title: Percutaneous transtracheal ventilation in an obstructed airway model in post-apnoeic sheep.
abstract: BACKGROUND
  Temporizing oxygenation by percutaneous transtracheal ventilation (PTV) is a recommended emergency technique in 'can't intubate, can't oxygenate' (CICO) situations. Barotrauma risk increases if expiration is obstructed. The Ventrain(®) is a new PTV device that assists expiration. Our aim was to compare key physiological outcomes after PTV with the Ventrain and the Manujet(®) in a large animal obstructed airway model.
  
  
  METHODS
  Five anaesthetized sheep had post-apnoea PTV performed for 15 min using the Ventrain or Manujet with the proximal airway completely or critically obstructed, yielding four ventilation protocols per sheep. After apnoeic desaturation ([Formula: see text]70%), a 4 s rescue breath was delivered. Subsequent 2 s breaths were delivered whenever the airway pressure fell <10 cm H2O.
  
  
  RESULTS
  Both devices achieved rapid re-oxygenation. There were marked device differences (Ventrain vs Manujet) in peak airway pressures with rescue (16 vs 40 cm H2O) breaths, minute ventilation (4.7 vs 0.1 litre min(-1)), and end-protocol pH (7.34 vs 7.01). There was no clinical evidence of barotrauma in any sheep after any ventilation protocol. An equilibration phase prevented large subatmospheric intrathoracic pressure development with Ventrain ventilation.
  
  
  CONCLUSIONS
  The Ventrain provided stable oxygenation and effective ventilation at low airway pressures during emergency PTV in critically obstructed airways. The Manujet provided effective temporizing oxygenation in this situation with hypoventilation necessary to minimize barotrauma risk. The nature and extent of airway obstruction may not be known in a CICO emergency but an understanding of device differences may help inform optimal ventilation device and method selection.
authors: Centre for Translational Physiology, University of Otago, Wellington, New Zealand Department of Paediatrics and Child Health, University of Otago, Wellington, New Zealand.
authors: M
authors: M
authors: Berry
authors: Centre for Translational Physiology, University of Otago, Wellington, New Zealand Department of Surgery and Anaesthesia, University of Otago, Wellington, New Zealand.
authors: Y
authors: Y
authors: Tzeng
authors: Centre for Translational Physiology, University of Otago, Wellington, New Zealand Department of Anaesthesia and Pain Management, Wellington Hospital, Wellington, New Zealand colin.marsland@paradise.net.nz.
authors: C
authors: C
authors: Marsland
mesh_terms: D000402:Airway Obstruction / Q000097:blood / Q000503:physiopathology / Q000628:therapy*; D000403:Airway Resistance; D000818:Animals; D001049:Apnea / Q000097:blood / Q000503:physiopathology / Q000628:therapy*; D001469:Barotrauma / Q000209:etiology / Q000517:prevention & control; D004195:Disease Models, Animal; D004630:Emergencies; D004867:Equipment Design; D005260:Female; D006611:High-Frequency Jet Ventilation / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D007442:Intubation, Intratracheal / Q000295:instrumentation / Q000379:methods; D010100:Oxygen / Q000097:blood; D010102:Oxygen Inhalation Therapy / Q000295:instrumentation / Q000379:methods; D010313:Partial Pressure; D034561:Sheep, Domestic
chemical_list: D010100:Oxygen
keywords: airway management; emergencies; jet ventilation, transtracheal