What is primarily adjusted in HFOV to obtain optimal oxygenation?

In high-frequency oscillatory ventilation (HFOV), mean airway pressure (Paw) is the primary variable adjusted to optimize oxygenation. This is because Paw significantly influences the amount of lung volume recruited and the overall surface area available for gas exchange.

Increasing the mean airway pressure can help improve the distribution of ventilation in the lungs and increase the overall functional residual capacity (FRC). By optimizing FRC, more alveoli are opened, which enhances the transfer of oxygen to the bloodstream.

While inspiratory time, respiratory rate, and tidal volume are important parameters in mechanical ventilation that can affect ventilation and the dynamics of gas exchange, they play a more significant role in achieving optimal carbon dioxide removal rather than primarily focusing on oxygenation. In the context of HFOV, where high frequencies and low tidal volumes are used, adjustments to Paw are critical for enhancing oxygenation without increasing the risk of lung injury.