Complex Patient-Ventilator Interactions

The following example shows a flow–time scalar with two distinct peaks. The initial peak corresponds to the patient’s inspiratory effort, followed by a rapid return of flow to baseline as the inspiratory effort ends and/or expiratory muscle contraction occurs.

Subsequently, a stepwise increase in flow appears as the ventilator delivers additional flow to compensate for a leak. A second flow peak is then observed, representing a new patient inspiratory effort.

The presence of a leak can be confirmed by the volume–time scalar failing to return to baseline before the onset of the next breath.