Capnography measures which parameter during procedural sedation?

Capnography measures which parameter during procedural sedation?

• A. End-tidal CO2.
• B. Oxygen saturation.
• C. Blood pressure.
• D. Heart rate.

Answer: (B)

Capnography monitors ventilation by measuring the CO2 in exhaled air, focusing on the end-tidal CO2—the level of CO2 at the end of expiration. This value provides a real-time picture of alveolar ventilation and airway patency, making it a sensitive indicator of respiratory status during procedural sedation. If a patient becomes hypoventilated or experiences an airway obstruction or apnea, the end-tidal CO2 changes promptly, allowing rapid interventions. Oxygen saturation, on the other hand, is tracked by pulse oximetry and reflects arterial oxygen content rather than ventilation per se; it may lag behind ventilation changes because of oxygen reserves. Blood pressure and heart rate monitor hemodynamics, not ventilation, so they don’t measure CO2.

Capnography monitors ventilation by measuring the CO2 in exhaled air, focusing on the end-tidal CO2—the level of CO2 at the end of expiration. This value provides a real-time picture of alveolar ventilation and airway patency, making it a sensitive indicator of respiratory status during procedural sedation. If a patient becomes hypoventilated or experiences an airway obstruction or apnea, the end-tidal CO2 changes promptly, allowing rapid interventions.

Oxygen saturation, on the other hand, is tracked by pulse oximetry and reflects arterial oxygen content rather than ventilation per se; it may lag behind ventilation changes because of oxygen reserves. Blood pressure and heart rate monitor hemodynamics, not ventilation, so they don’t measure CO2.