Preferentially ventilate dependent lung
Maximally perfuse dependent lung
In disease, V/Q matching can be optimised by specific positioning of patient
Unilateral lung disease – greatest benefit when pts unaffected lung is in dependent position
if you put affected lung in dependent position - there will be ventilation, but no perfusion, causing V/Q mismatch, causing hypoxemia
Bilateral lung disease greatest benefit:
right lung in dependent position as the right lung is bigger
high sitting - bases will be much bigger, making them dependent
