In ARDS, an imbalance between blood and air flow develops, leading to poor gas exchange. Prone positioning redistributes blood and air flow more evenly, reducing this imbalance and improving gas exchange.

Why is prone positioning most advocate in ARDS?

Placing a person in the prone position reduces the pleural pressure gradient from nondependent to dependent regions, in part through gravitational effects and conformational shape matching of the lung to the chest cavity. As a result, lung aeration and strain distribution are more homogeneous.

When should ARDS patients be prone?

There is no known ideal timing or duration for prone positioning for ARDS. Some studies used alternating cycles of four hours prone, two hours supine throughout the day; others kept patients prone for 20 continuous hours per day with a four hour supine epoch for intensive nursing care.