Very high respiratory rates in HFOV typically result in:

High-frequency oscillatory ventilation (HFOV) employs rapid respiratory rates to provide adequate ventilation and oxygenation while minimizing lung injury. In this mode, the aim is to achieve gas exchange primarily through the oscillations of a small tidal volume rather than traditional larger tidal volumes.

When the respiratory rate is very high in HFOV, it typically results in low alveolar pressure changes. This is because the oscillations, while frequent, are delivered with smaller inflation and deflation pressures compared to conventional ventilation. The alveolar pressure changes are minimized to avoid barotrauma and volutrauma, making it safer for patients with compromised lung function, such as those with Acute Respiratory Distress Syndrome (ARDS).

While high respiratory rates can lead to adjustments in other parameters like mean airway pressure, the key point with very high rates is that they keep the alveolar pressures relatively stable, thus preventing large swings that could contribute to lung injury. This focus on maintaining low alveolar pressure changes is what allows HFOV to be a suitable choice for delicate pulmonary conditions.