Managing Early Cycling in Pressure Support Mode

In this case, the breaths are initiated by the patient. During the expiratory phase, the expiratory flow-time scalar shows a deviation toward the baseline, indicating reduced expiratory flow. This occurs due to the continuation of the patient’s inspiratory effort even after the ventilator has transitioned to expiration, a phenomenon known as early cycling. 

Early cycling happens when the ventilator switches to expiration before the patient’s neural inspiratory effort is complete, typically because the mechanical inflation time is shorter than the neural inspiratory time. 

To address this, the mechanical inflation time can be lengthened to better align with the neural inspiratory time. In pressure support mode, this can be achieved by reducing the percentage of flow termination criteria. 

In this case, the initial end-inspiration/Expiratory Trigger Sensitivity (ETS) was set at 30%. Adjusting the ETS to 15% resolved the early cycling.