Airway Pressure Release Ventilation (APRV)
This mode of ventilation became commercially available in the United States in the mid 1990s. It uses a different mode of ventilation than other methods.
Conventional modalities use a strategy that begins the ventilation cycle at a lower baseline pressure and with an increase in airway pressure to open the alveoli and produce ventilation.
APRV begins the ventilation cycle at an elevated airway pressure and intermittently releases the pressure (i.e., deflates the lungs) to create tidal ventilation and allow removal of carbon dioxide.
APRV has been described as continuous positive airway pressure with brief releases of pressure. While teleologically similar, APRV differs from CPAP in that it allows for both ventilation (i.e., CO2 removal) and oxygenation.
APRV is now used commonly in acute lung injury to ventilate using maximum lung protection strategies.
Some advantages of its use include the reduction of patient sedation, the ability to breath spontaneously throughout the cycle, lower airway pressures, minimal effects on the cardiovascular system (e.g., mimimal effects on venous return), and elimination of neuromuscular blockade.