Where in the respiratory cycle does the lower inflection point typically occur?

The lower inflection point typically occurs at the end of inspiration. This point represents a change in the compliance of the lung and indicates the transition from low to high compliance of the lung tissues. At this stage, the alveoli are becoming more inflated, but as they reach a certain volume at the end of inspiration, their compliance begins to increase significantly, allowing further expansion with minimal pressure increase. Understanding this point can improve strategies for mechanical ventilation by helping clinicians identify when to adjust pressure settings to optimize ventilation and prevent barotrauma.

In contrast, the inflection points during expiration, at the beginning of expiration, or mid-inspiration do not accurately reflect the changes in compliance that characterize the lower inflection point, which is specifically tied to alveolar recruitment at the end of the inspiration phase.