Which of the following describes high-frequency oscillatory ventilation (HFOV)?

• A. Uses low rates of 1-5 Hz
• B. Uses a sinusoidal waveform with very high rates
• C. Involves only passive processes for inspiration and expiration
• D. Emphasizes larger tidal volumes for effective ventilation

Answer: (B)

High-frequency oscillatory ventilation (HFOV) is characterized by its use of a sinusoidal waveform combined with very high rates, typically ranging from 3 to 15 Hz, which equates to 180 to 900 breaths per minute. This distinct mode of ventilation enables minimal tidal volumes, allowing for better ventilation-perfusion matching while avoiding barotrauma and volutrauma, which are more common with traditional mechanical ventilation strategies.

The sinusoidal waveform allows for continuous airway pressure changes, contributing to the recruitment of collapsed alveoli and the maintenance of lung recruitment strategies. HFOV's effectiveness lies in its ability to provide ventilation at these high frequencies without needing larger tidal volumes, which is crucial for patients with conditions like ARDS (Acute Respiratory Distress Syndrome), where lung protective strategies are vital.

The use of sinusoidal waveforms with high rates is the core distinction of HFOV, making it an important alternative in specific clinical settings.