Indeed, APRV can be viewed as IRV applied with a very high I:E ratio and delivered using an open circuit.
About the same time as APRV was being described, Marcel Baum in Austria proposed alternating CPAP between two levels of adjustable magnitude and duration, with much the same rationale.
The essential differences between APRV and Baum's Bi-Phasic ventilation--which he termed BIPAP--rest in the mean airway pressure and in the duration and the nature of the floor under the low pressure phase.
APRV is open to the same concern regarding tidal collapse during circuit decompression.
Unlike HFO, APRV (and its conceptual cousin, bi-level) is now integrated into many full-featured ICU ventilators, dramatically improving chances of its widespread acceptance.
APRV is not really a mode, but a platform whose level of support can be reduced to keep in step with the patient's changing need.
Fervent advocates for HFO and APRV are not difficult to find.
APRV is an intermittent ventilatory support mode that creates the potential for a patient's spontaneous breathing at any point during the ventilator cycle.
APRV may be thought of as alternating levels of CPAP with or without pressure support.
APRV fashions tidal "volume" swings via pressure release; from Phigh to Plow.