There's a nice rundown on APRV over at Resus Review.
A few important things to keep in mind about APRV:
Its main use is hypoxemic respiratory failure, typically ARDS.
Its purported advantages which include preserving spontaneous breathing and the ability to recruit alveoli without lung overdistention or adverse hemodynamics are physiologically appealing but supported only by low level data.
Though gaining in popularity its role is not well established and it is generally relegated to a rescue modality, to be used when conventional methods are not working.
Autopeep is intentional but ventilation is on a lower portion of the compliance curve than with conventional ventilation.
If some parts of the above linked post are difficult to understand it may be helpful to read the review published in CCJM which I linked in this post.