Pressure-regulated volume control (PRVC) is an adaptive mode of ventilation that attempts to achieve set tidal volume at the lowest possible inspiratory airway pressure by using breath-to-breath feedback to adjust flow. Because it theoretically combines the best of pressure control (variable flow) and volume control (guaranteed minute ventilation) modes, PRVC is often the initial mode of ventilation for patients initiated on mechanical ventilation.
However, just like anything else, some drawbacks must be considered. For example, suppose a patient’s work of breathing is high (e.g., pain, anxiety, or mixed respiratory and metabolic acidemia), and they are trying to pull a lot of flow. In that case, PRVC will often lower the delivered inspiratory pressure to reach the set tidal volume. This reduction in vent support can result in discomfort, patient-ventilator dyssynchrony, and an even higher work of breathing.
Furthermore, a patient’s increased demand for inspiratory flow can result in the delivery of higher tidal volumes, and when compounded by tachypnea, can easily result in auto-PEEP and precipitate hemodynamic derangements.
In my cardiac anesthesia and CVICU practices, I use neuromuscular blocking agents if I’m intubating. Because of the initial, stable respiratory drive, I utilize PRVC; however, I’m more mindful of PRVC’s drawbacks with sedation holidays.
Drop me a comment with your thoughts about PRVC!
