Steps to Waveform Interpretation

  1. Initiation: Determine if the breath is initiated by the patient, the ventilator, or something else (i.e. cardiac oscillations)
  2. Constant: During inspiration ignore the waveform that should be relatively constant and pay close attention to the one that can change
    1. Volume control = flow is constant, pressure changes
    2. Pressure control = pressure is constant, flow changes
  3. Exhalation:  Observe the expiratory flow for patient activity
  4. Define: Is there dyssynchrony between the patient and ventilator, or simply bad lung mechanics

Don’t forget to look at your patient!