Which parameters are typically defined in APRV?

• A. FiO2, T-high, T-low, P-high, P-low/PEEP
• B. Respiratory Rate, FiO2, PEEP
• C. Tidal Volume, Respiratory Rate
• D. PIP

Answer: (A)

APRV relies on two pressure levels and two time settings to balance keeping the lungs recruited with allowing ventilation. The high pressure (P-high) is held for a relatively long time (T-high) to keep alveoli open and improve oxygenation. The low pressure (P-low, often called PEEP) is held for a shorter time (T-low) to permit some exhalation without letting the lungs collapse. FiO2 is defined to control the amount of oxygen delivered. Together, these parameters shape both recruitment and ventilation, while tidal volume isn’t set directly in APRV—the actual volume depends on the pressures and the patient’s lung mechanics. Respiratory rate isn’t a fixed input either; it emerges from the timing of the two phases. PIP isn’t a predefined APRV setting; you manage using P-high and P-low. So the typical defined parameters are FiO2, T-high, T-low, P-high, and P-low/PEEP.