Which monitoring method is best described as measuring the CO2 concentration in exhaled air to assess ventilation?

Which monitoring method is best described as measuring the CO2 concentration in exhaled air to assess ventilation?

• A. Pulse Oximetry
• B. End-tidal CO2 Capnography
• C. Auscultation Alone
• D. Chest X-ray

Answer: (B)

End-tidal CO2 capnography is the monitoring method that measures the CO2 concentration in exhaled air to assess ventilation. By sampling the gas at the end of expiration, it reflects how effectively CO2 is being eliminated by the lungs, which depends on alveolar ventilation and airway patency. The capnogram waveform and the end-tidal CO2 value provide real-time feedback on ventilation status and can rapidly indicate issues like airway obstruction, hypoventilation, apnea, or impaired perfusion. Normal end-tidal CO2 in adults is typically around 35–45 mmHg; deviations point to ventilation problems even if other signs look normal. In contrast, pulse oximetry measures oxygen saturation in the blood, not CO2; auscultation alone cannot quantify CO2 or ventilation status; and chest X-ray shows anatomy and static conditions rather than continuous ventilation monitoring.

End-tidal CO2 capnography is the monitoring method that measures the CO2 concentration in exhaled air to assess ventilation. By sampling the gas at the end of expiration, it reflects how effectively CO2 is being eliminated by the lungs, which depends on alveolar ventilation and airway patency. The capnogram waveform and the end-tidal CO2 value provide real-time feedback on ventilation status and can rapidly indicate issues like airway obstruction, hypoventilation, apnea, or impaired perfusion. Normal end-tidal CO2 in adults is typically around 35–45 mmHg; deviations point to ventilation problems even if other signs look normal.

In contrast, pulse oximetry measures oxygen saturation in the blood, not CO2; auscultation alone cannot quantify CO2 or ventilation status; and chest X-ray shows anatomy and static conditions rather than continuous ventilation monitoring.