High frequency oscillation ventilation

Background

• High Frequency Oscillation Ventilation (HFOV) is an alternative method for mechanical ventilation in difficult to oxygenate in critically ill ARDS patients.
• Studied in patients with PaO2/FiO2 < 200
• Goal is to maintain alveolar recruitment for adequate gas exchange and decrease lung injury/atelectrauma
  • Low tidal volumes based around mean airway pressures to keep alveoli open
  • Delivered at high frequency

Pros

• Limits VILI
• May improve oxygenation when ECMO not available

Cons

• No difference or likely to cause harm in adult ARDS patients
• Requires heavy sedation
• Increase mean airway pressures may result in more hemodynamic instability

Procedure

Example protocol from Oscillate trial

• Set FiO2 at 100%
• Recruitment maneuver of 40 cmH2O PEEP for 40 seconds
• I:E time of 1:2
• Initiate high frequency ventilation → 3-15 Hz
• VT minimized to keep pH >7.25
  • Goal of 1-4 ml/Kg
• Maintain mean airway pressure of 30 cmH2O with pressure adjusted to maintain a PaO2 of 55-80 mmHg
• Reversion to standard ventilation of mean airway pressure was ≤24 cmH2O for 12 hours or anytime when ≤20 cmH2O
• Re-initiation of HFOV if FIO2 >0.4 or PEEP >14 cmH2O for >1 hour in the subsequent 48 hours

Targets

• pH>7.25
• SpO2 >88% or PaO2 >55mmHg

Oxygenation altered by:

• FiO2
• Mean airway pressures

Ventilation altered by:

• Frequency
  • Decrease frequency to increase TV and ventilation
• Inspiratory time
• Amplitude of oscillations

See Also

Mechanical Ventilation Pages

• Noninvasive ventilation
• Intubation
  • Rapid Sequence Intubation (RSI)
  • Difficult airway algorithm
  • Supraglottic airway
  • Nasal intubation
• Deterioration after intubation
• Ventilation settings
• Ventilation modes
• Ventilator high pressures
• Ventilator associated lung injury (VALI)
• Recruitment maneuver
• Ventilation weaning
• Extubation

External Links

• Life in the Fast Lane - for an excellent review and tutorial
• Oscillate
• OSCAR

References

Authors

Claire