When a bilevel ventilator is used in the spontaneous/timed mode, at what point does the ventilator employ the timed feature?

Question

Quizplus · Accepted Answer

Most bilevel pressure-targeted ventilators suitable for NIV feature CPAP, spontaneous, timed, and spontaneous/timed operating modes. In the spontaneous/timed mode, the flow-trigger feature is activated. The ventilator responds to a threshold level of inspiratory flow or to a change in volume that is initiated by the patient's spontaneous respiratory effort. At the inspiratory flow threshold, the ventilator delivers additional gas flow to reach the preset inspiratory positive airway pressure (IPAP). Exhalation occurs after the inspiratory flow peaks and then decreases to a threshold level. The ventilator triggers in the timed mode only in the event of prolonged apnea.

When a Bilevel Ventilator Is Used in the Spontaneous/timed Mode