Final answer:
The prone position is used to decrease atelectasis and improve refractory hypoxemia in patients with ARDS, due to its ability to improve lung mechanics and oxygenation.
Step-by-step explanation:
The prone position is known to be effective in decreasing atelectasis and improving refractory hypoxemia in patients with acute respiratory distress syndrome (ARDS). This position helps in improving oxygenation by redistributing blood flow and enhancing the removal of secretions. The tripod, supine, and lateral positions are other positions used for various respiratory conditions, but for ARDS specifically, the prone position is often considered the most beneficial for the aforementioned outcomes.