What is the normal end-tidal CO2 (ETCO2) range?

What is the normal end-tidal CO2 (ETCO2) range?

• A. 25-35 mmHg
• B. 35-45 mmHg
• C. 45-55 mmHg
• D. 15-25 mmHg

Answer: (B)

End-tidal CO2 is the CO2 level measured at the end of an exhaled breath, read by capnography. In a healthy adult, alveolar CO2 is around 40 mmHg, so the end-tidal value normally falls in the 35–45 mmHg range. This window indicates that ventilation is effectively removing CO2. Values below 35 suggest too much CO2 is being blown off or there’s reduced CO2 production, while values above 45 suggest hypoventilation or increased CO2 production. In airway management, staying within this range helps confirm adequate ventilation and proper tube placement. So, the normal ETCO2 range is 35–45 mmHg.

End-tidal CO2 is the CO2 level measured at the end of an exhaled breath, read by capnography. In a healthy adult, alveolar CO2 is around 40 mmHg, so the end-tidal value normally falls in the 35–45 mmHg range. This window indicates that ventilation is effectively removing CO2. Values below 35 suggest too much CO2 is being blown off or there’s reduced CO2 production, while values above 45 suggest hypoventilation or increased CO2 production. In airway management, staying within this range helps confirm adequate ventilation and proper tube placement. So, the normal ETCO2 range is 35–45 mmHg.