Respirator Cycle Control Modes

The goal of mechanical ventilation is to provide or improve ventilation, oxygenation, lung mechanics, and patient comfort while minimizing complications. Traditionally, volume control modes have been favored because of the ability to guarantee a preset tidal volume (VT) and minute ventilation (VE) enabling straightforward manipulation of ventilation in response to changes in the partial pressure of carbon dioxide in the blood (PaCO2). However, during volume control modes, there is no guaranteed limit of peak airway pressure. This lack of limitation of airway pressure may result in high peak airway pressures associated with changes in the patient’s compliance and resistance, causing alveolar overdistension and barotrauma. In contrast, pressure control ventilation (PCV) allows control, or limitation, of the peak inspiratory pressure (PIP) and inspiratory time (Ti) with no guarantee of VT