Vyaire Avea - Volume Controlled Ventilation

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Volume controlled ventilation
Avea ventilator intra-breath demand system
The Avea ventilator features a unique intra-breath demand system in volume controlled
ventilation designed to provide additional flow to the patient during periods of demand.
The Avea ventilator measures the peak inspiratory pressure (Ppeak) every 2 ms throughout
the breath cycle and sets a virtual pressure support target at the greater of PEEP +
2 cmH
2
O or Ppeak–2 cmH
2
O.
The minimum virtual pressure support level is set PEEP + 2 cmH
2
O, and the maximum is
two times the set PEEP. Simultaneously, the ventilator monitors and compares the Ppeak
measurement to its previous value. If the Ppeak decreases by 2 cmH
2
O, the ventilator
recognizes the patient demand and automatically switches over to deliver a pressure
support breath at the virtual pressure support target. This allows flow to exceed the set
peak flow, thereby meeting patient demand.
Once the set tidal volume has been delivered, the ventilator looks at the inspiratory flow.
Should the peak inspiratory flow be greater than set peak flow, the ventilator determines
that the patient continues to demand flow. The breath then cycles when inspiratory flow
falls to 25% of the peak inspiratory flow. If the peak inspiratory flow is equal to the set flow,
the ventilator determines the patient is not demanding flow and ends the breath as a
volume control breath.