Definitions 

Bhavani Shankar Kodali MD

 

Capnometry:

The measurement and display of carbon dioxide (CO2) on a digitial or analogue monitor. Maximum inspiratory and expiratory CO2 concentrations during a respiratory cycle are displayed.

 

Capnography:

 A graphic display of instantaneous CO2 concentration (FCO2) versus time or expired volume during a respiratory cycle (CO2 waveform or capnogram)

 

Capnograms:

CO2 waveforms which can be of two types: FCO2 can be plotted against expired volume (SBTCO2 curve /volume capnogram/ CO2 expirogram) or against time (time capnogram) during a respiratory cycle.

 

PACO2:

 Partial pressure of CO2 in the alveoli.

 

PaCO2:

 Partial pressure of CO2 in arterial blood.

 

PETCO2:

 Partial pressure of CO2 at the end of expiration.

 

(a-ET)PCO2:

 Arterial to end-tidal CO2 tension/pressure difference or gradient.

 

PvCO2:

 Partial pressure of CO2 in mixed venous blood.