What does capnography measure and what is its typical use at the EMR level?

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

Answer: (C)

Capnography measures the amount of carbon dioxide in exhaled air, focusing on end-tidal CO2—the CO2 at the end of a breath. It provides a continuous capnogram waveform that reflects how effectively a patient is ventilating. At the EMR level, its typical use is to monitor ventilation status and verify airway patency and placement (for example, confirming a tube is in the trachea after intubation). It’s also useful during CPR or respiratory distress to gauge ventilation effectiveness and to detect changes suggesting return of spontaneous circulation (a rising end-tidal CO2). Oxygen saturation, blood pressure, and heart rate are measured by other devices; capnography specifically tracks CO2 in exhaled air.