When the Breath Won't End: Air Leaks in Pressure Support Mode

These breaths are patient triggered breaths. Due to significant air leak from the mask, the % flow cycling threshold is not reached, and the ventilator fails to terminate inspiration. Meanwhile, the patient completes one full breath cycle (inspiration and expiration) and initiates another, leading to a second peak in the inspiratory flow-time scalar. In pressure control or pressure support modes, an air leak causes the ventilator to increase flow in an attempt to maintain the set pressure. As a result, flow does not drop to cycling threshold, leading to prolonged inspiration. To prevent excessively long inspiratory phase, the ventilator activates a backup time based mechanism to terminate inspiration (Time cycling).