When the Patient Pulls Hard: Vigorous Effort in Volume Control Mode

These breaths are initiated by the patient, and the inspiratory limb of the pressure-time scalar dips below the baseline due to the patient's strong inspiratory efforts (Pmus). This negative intrathoracic pressure, created by the inspiratory muscles, is reflected on the pressure-time scalar. This phenomenon, previously referred to as flow starvation, is now termed work shifting.

The steep pressure rise during the inspiratory pause suggests relaxation of the inspiratory muscles and/or active exhalation.

The expiratory flow-time scalar shows a loss of the typical exponential decay pattern due to active exhalation.

Note: The red dotted lines depict the typical appearance of scalars in volume control mode when the patient is either passive or exerting minimal effort in breathing.