title: The mouth-to-bag resuscitator during standard anaesthesia induction in apnoeic patients.
abstract: OBJECTIVE
  Ventilation of a non-intubated emergency patient by inexperienced rescuers with a standard bag-valve device may result in high inspiratory flow rates and subsequently high airway pressures with stomach inflation. Therefore, a self-inflating bag has been developed that requires lay rescuers to blow up a single-use balloon inside an adult bag-valve device, which, in turn, displaces air within the bag towards the patient. This concept has been compared to standard adult bag-valve devices earlier in bench models but not in patients.
  
  
  METHODS
  An anaesthetist who was blinded to all monitor tracings ventilated the lungs of 40 apnoeic patients during routine anaesthesia induction either with a standard bag-valve device or with the mouth-to-bag resuscitator in a random order. Study endpoints were peak inspiratory flow rates, peak airway pressure, tidal volumes and inspiratory time.
  
  
  RESULTS
  Peak inspiratory flow was 40+/-10lmin(-1) for the standard bag-valve device versus 33+/-13lmin(-1) for the mouth-to-bag resuscitator (P<0.0001); peak airway pressure was 17+/-5cmH(2)O versus 14+/-5cmH(2)O (P<0.0001); inspiratory tidal volume was 477+/-133ml versus 644+/-248ml (P<0.001) and inspiratory time was 1.1+/-0.3s versus 1.9+/-0.6s (P<0.0001).
  
  
  CONCLUSIONS
  Employing the mouth-to-bag resuscitator during simulated ventilation of a non-intubated patient in respiratory arrest significantly decreased peak inspiratory flow and peak airway pressure and increased inspiratory tidal volume and inspiratory times compared to a standard bag-valve device.
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Innsbruck Medical University, Anichstrasse 35, 6020 Innsbruck, Austria. holger.herff@i-med.ac.at
authors.forename: Holger
authors.initials: H
authors.lastname: Herff
authors.forename: Peter
authors.initials: P
authors.lastname: Paal
authors.forename: Thomas
authors.initials: T
authors.lastname: Mitterlechner
authors.forename: Achim
authors.initials: A
authors.lastname: von Goedecke
authors.forename: Karl H
authors.initials: KH
authors.lastname: Stadlbauer
authors.forename: Wolfgang G
authors.initials: WG
authors.lastname: Voelckel
authors.forename: Angelika
authors.initials: A
authors.lastname: Zecha-Stallinger
authors.forename: Volker
authors.initials: V
authors.lastname: Wenzel
mesh_terms: D000328:Adult; D000758:Anesthesia; D001049:Apnea / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006801:Humans; D001239:Inhalation; D008297:Male; D012123:Pulmonary Ventilation; D012121:Respiration, Artificial / Q000295:instrumentation*; D012151:Resuscitation / Q000295:instrumentation*; D013990:Tidal Volume