Although traditionally used in neonates, HFOV is becoming increasingly popular for select adult patients with ALI/ARDS.
Benefits of HFOV include:
use of smaller tidal volumes than conventional ventilation
maintains alveoli open at a relatively constant airway pressure thereby preventing atelectrauma
improves ventilation/perfusion
Indications for use of HFOV are when:
conventional ventilator settings require an FiO2 > 70% and PEEP > 14 cm H2O OR
pH < 7.25 despite higher tidal volumes and plateau pressures > 30 cm H2O
Key variables, along with suggested initial settings, for HFOV include:
Frequency: 4 - 7 Hertz
Amplitude: 70 - 90 cm H2O
Mean airway pressure: 5 cm H2O greater than last plateau pressure measured on conventional setting
Bias flow: 40 L/min
Inspiratory time: 33%
FiO2: 100%
References
Stawicki SP, Goyal M, Sarani B. High frequency oscillatory ventilation and airway pressure release ventilation: a practical guide. Journal of Intensive Care Medicine 2009:24(4):215-229.
