Unlike spontaneous breathing or conventional ventilation, the time spent at maximal inflation is typically much longer than time deflated. Time low is minimized to prevent collapse of alveoli and barotrauma. The video below shows shows treated pig lungs being ventilated with typical APRV settings.
Airway pressure release ventilation (APRV) is a method of mechanical ventilation. Also known as inverse ratio or bilevel ventilation, the lung alveoli are opened with a high level pressure and ventilation is applied as the lung cycles between the high pressure and the set low pressure. In a previous post we discussed the details of setting up APRV settings and adjustments. I use this mode primarily for patients ARDS.