Figure 2.

It shows illustrations of pressure and flow waves of some of the common types of patient-ventilator synchrony during pressure support ventilation. (a) The figure illustrates pressure and flow waves during pressure support, where the patient tries to breathe, but he was unable to generate the needed effort required to trigger the ventilator. These minor efforts increase the work of breathing without generating enough tidal volume. (b) The figure illustrates pressure and flow waves during pressure support. When the ventilator does not meet the patients' demand for tidal volume, double-triggering may appear. In this example, two consecutive breaths occur with an interval of less than half of the mean inspiratory time. (c) The figure illustrates pressure and flow waves during pressure support. The machine delivers breaths in the absence of patient's effort, as inferred by the absence of a decrease in airway pressure prior to the machine-delivered breath. The illustration demonstrates the occurrence of more than three consecutive pressurizations at a ventilator frequency. (d) The figure illustrates pressure and flow waves during pressure support. The illustration shows an anomalous flow wave and an increased inspiratory time due to inspiratory air leak