Kingst Commercial and Trade Co.,Ltd.
Kingst Commercial and Trade Co.,Ltd.

Use of a Capnography Monitor

The carbon dioxide detection technology uses a carbon dioxide gas detector. The carbon dioxide detector accurately detects carbon dioxide. It adopts an infrared imported carbon dioxide sensor with stable signal. The capnography monitor has the advantages of high sensitivity and precision.


1. Understand the capnography monitor


Capnography monitor is a non-invasive measurement of the partial pressure of carbon dioxide (CO2) in the exhaled breath, expressed as a time-varying CO2 concentration. The CO2 concentration versus time is graphically represented by a CO2 waveform or capnogram. Changes in capnography shape are diagnostic of disease conditions, while changes in end-tidal CO2 (EtCO2), the concentration of maximal CO2 at the end of each tidal breath, can be used to assess disease severity and response to therapy. Capnography monitor is also the most reliable indicator of placing an endotracheal tube in the trachea after intubation.


Oxygenation and ventilation are distinct physiological functions that must be assessed in intubated and spontaneously breathing patients. Pulse oximeters provide instantaneous feedback on oxygenation. Capnography provides immediate information on ventilation (the efficiency of the lung system to remove CO2), perfusion (the efficiency of transporting CO2 through the vascular system), and metabolism (the efficiency of cell metabolism to produce CO2). Capnography became a routine part of anesthesia practice in Europe in the 1970s and in the United States in the 1980s. It is now part of the standard of care for all patients receiving general anesthesia and is part of routine monitoring in prehospital and acute care settings.


2. The principle of operation of capnography monitor


Capnography monitors measure gas concentration or partial pressure in one of two configurations: main flow or side flow. Mainstream devices measure breathing gas (CO2 in this case) directly from the airway, with sensors located on the airway adapter in the center of the endotracheal tube (ETT). Lateral flow devices measure breathing gas through a nasal cannula by inhaling a small sample from exhaled breath through the cannula to a sensor located within the monitor.


3. The formation of capnography monitor traces


A capnometer monitor is a trace of CO2 levels over time. As the CO2 level at the sampling point drops and rises over time due to inhalation and exhalation, you get a capnograph trace. At a very basic level, you can think of a capnography as a line that alternates between baseline and higher levels, and then descends again near the baseline. Lines near the baseline represent inspiration, and higher lines represent expiration.