Ventilator Modes Reference

Explore different ventilator modes, their clinical applications, advantages, and key settings. Compare up to 3 modes side-by-side to understand the differences in their applications and parameters.

How to Read Ventilator Waveforms
Pressure-Time Waveforms
  • Rectangular: Seen in pressure-controlled ventilation. Rapid rise to set pressure, plateau, then rapid fall.
  • Decelerating: Seen in pressure support. Rapid rise, then gradual decrease as flow decelerates.
  • Biphasic: Alternating high and low pressure levels as seen in APRV or BiPAP modes.
Flow-Time Waveforms
  • Constant: Seen in volume control. Square-wave pattern with constant inspiratory flow.
  • Decelerating: High initial flow that gradually decreases, often in pressure-targeted modes.
  • Oscillatory: Rapid, small-volume oscillations seen in HFOV with active inspiration and expiration.
Volume-Time Waveforms
  • Ascending Ramp: Linear increase during inspiration in volume control, followed by constant expiratory phase.
  • Exponential Rising: Curved inspiratory limb seen in pressure control as flow decelerates.
Waveform Abnormalities to Watch For
  • Auto-PEEP: Expiratory flow doesn't return to zero before next breath.
  • Patient-Ventilator Dyssynchrony: Irregular waveforms, double-triggering, or ineffective triggering attempts.
  • Airway Resistance: Pressure rises rapidly with decreased flow (e.g., mucus plugging, bronchospasm).
  • Leak Detection: Inspiratory volume greater than expiratory volume; pressure fails to reach target.