Ventilator Assisted Pre-Oxygenation (VAPOX) is a protocol developed for using a ventilator during the peri-intubation period primarily for pre-oxygenation.


  • To deliver PEEP + machine controlled ventilation during the following peri-intubation periods:
    • Pre-Oxygenation – prior to administration of sedative and paralytic drugs
    • Apnoea –  post onset of drugs until attempt at intubation
    • Re-Oxygenation – post an unsuccessful intubation attempt

While it could be used in any patient, it has particular proposed benefit for patients who require PEEP during the pre-oxygenation phase to achieve normal/near-normal oxygenation saturations.


  • Provides PEEP through the whole pre-intubation period (except during attempts at intubation)
  • Provides machine controlled assisted ventilation
    • This is an alternative to human delivered bag-valve mask ventilations which frequently result in excessive ventilation that increase risk of gastric insufflation and aspiration.
    • It has been designed to provide a maximum positive inspiratory pressure of 15cm H20. It is thought that the lower oesophageal sphincter is unlikely to allow gastric insufflation below pressures of 20cm H20. By this rationale it is expected to allow safe ventilations during the apnoea period where traditionally in Rapid Sequence Intubation the patient receives no external ventilation.


  • Protocol designed for Hamilton T1 Ventilator
  • Select NIV-ST Mode
  • Key settings:
    • RR 6-8 breaths/minute
    • Pressure support = 10cm H20
    • PEEP = 5cm H20
    • FiO2 = 1.0 (100%)
  • Other settings
    • Expiratory trigger sensitivity = 50%
    • Inspiratory Flow trigger = 2L/min
    • Inspiratory Time (Ti) = 2 sec
    • P-ramp = 50ms

Note this protocol has been proposed based on case series and has not been subject to randomised controlled trials. Clinicians need to consider individual risk/benefit analysis for their patients if considering using this protocol.

For more information consult the original publication:

Grant S, Khan F, Keijzers G, Shirran M, Marneros L. Ventilator-assisted preoxygenation: Protocol for combining non-invasive ventilation and apnoeic oxygenation using a portable ventilator. Emerg Med Australas. 2016;28:67-72.

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