Alaris® EtCO2 module
Topic 1: Overview of End Tidal CO2 Monitoring

Resources

What Are the Structures That Make Up the Normal EtCO2 Waveform Tracing?

• A-B: Baseline = no CO2 in breath
• B-C: Exhalation begins, rapid rise in CO2
• C-D: Alveolar plateau
• D: End of expiration (end tidal)
• D-E: Inhalation

NOTE: Upward stroke of waveform occurs with exhalation, whereas downward stroke occurs with inhalation. This is the opposite of other respiratory waveforms. Waveform will deviate from normal when a physiologic or mechanical disruption occurs.