Airway & Respiratory, Patient Care

EMS Airway: What is Capnography?

The word “capnography” is derived from a Latin twist based on an original Greek concept. The Greeks first wrote about combustion centers throughout the body that they said released a byproduct called “Kapnos,” or in Latin, “Capnos;” both are words for “smoke.” What the Greeks called “combustion,” we now call metabolism and what they called “smoke,” today is termed carbon dioxide.

Capnography is a device that is placed at the lips to detect the presence of carbon dioxide in exhaled air, called “End-Tidal Carbon Dioxide” or ETCO2 for short. Older, qualitative “colorimetric” capnography devices simply changed color when sensing the presence of carbon dioxide. Today’s EMS monitors use quantitative technology that combines a numerical readout (capnometer) with a waveform to measure and display the pressure of carbon dioxide in exhaled air.  ETCO2 is a pressure measurement in mmHg and not a percentage or “count” like parts per million.

Click here to continue to EMS Airway to read and watch more. (Free registration is required to view this content.)

Above photo by Rick McClure