High-frequency oscillation in paediatric respiratory failure

High-frequency oscillatory ventilation (HFOV) allows effective recruitment of atelectasis while delivering minimal tidal volumes at rates exceeding the normal respiratory rate. HFOV is considered in the setting of failing conventional ventilation in patients with acute lung injury, indicated by arterial hypoxaemia despite peak inspiratory pressures of more than 35 cm H2O or oxygenation indices of more than 13 on two or more arterial blood gas analyses. The initial mean airway pressure on HFOV is set 5–8 cm H20 higher than the last mean airway pressure during conventional ventilation. Increasing the mean airway pressure increases alveolar recruitment and oxygenation, whereas CO2 elimination is directly related to the peak-to-trough pressure amplitude, and negatively correlated with the device frequency. Weaning from HFOV and the transition to conventional ventilation is considered on resolving lung disease and minimal settings on the oscillator (mean airway pressure 15−20 cm H2O, amplitude ⩽4.0, FiO2 <0.6).