Airway Pressure Release Ventilation: A Field Guide for the Emergency Physician

Airway pressure release ventilation (APRV) is a mode of ventilation that uses high airway pressures to recruit and maintain patients' lung volumes. The goal of this mode of ventilation is 2-fold: first, to maintain patients as close to their functional residual capacity as possible and second, to promote safe spontaneous breathing. APRV should essentially be viewed as continuous positive airway pressure (CPAP), with intermittent releases of that pressure to metabolically support patients who are incapable of managing their ventilatory load. As patients recruit and lungs approach the patients' natural lung volumes, their ability to breathe spontaneously and manage their own ventilatory needs improves. Eventually, patients are able to fully support their ventilatory needs and no longer require any release breaths to maintain normal CO₂ levels. Now, patients can be "stretched" to CPAP.