From the Research
Pressure Support (PS) is the preferred mode for spontaneously breathing patients who need some assistance, while Pressure Regulated Volume Control (PRVC) is better suited for patients who require more ventilatory control with pressure protection, as evidenced by the most recent study 1.
Overview of Ventilation Modes
PS is a patient-triggered, pressure-limited mode where the patient initiates each breath and determines their own respiratory rate and inspiratory time, while the ventilator provides a set pressure to assist. This mode is ideal for weaning patients from mechanical ventilation as it strengthens respiratory muscles while providing support. On the other hand, PRVC is a dual-control mode that guarantees a set tidal volume while using the lowest necessary pressure, automatically adjusting pressure levels based on lung compliance.
Clinical Applications
PRVC is beneficial for patients with changing lung mechanics, such as those with ARDS or pulmonary edema. The choice between these modes depends on the patient's clinical condition, respiratory drive, and weaning potential. According to 1, understanding the interaction between patient effort and tidal volume is crucial in selecting the appropriate ventilation mode.
- PS typically uses settings of 5-15 cmH2O.
- PRVC requires setting both a target tidal volume (usually 6-8 mL/kg ideal body weight) and maximum pressure limit (typically 30-35 cmH2O).
Evidence-Based Recommendations
The most recent study 1 provides a conceptual model for the non-linear interaction between pressure support, patient effort, and tidal volume, supporting the use of PS for patients who can benefit from assisted ventilation with a focus on protecting the lungs and diaphragm. While older studies 2, 3, 4, 5 offer insights into the mechanisms and effects of PS and PRVC, the latest evidence 1 guides the recommendation for preferring PS in appropriate clinical contexts, considering the importance of patient-ventilator synchrony and lung-protective strategies.