CO2: carbon dioxide; ETCO2: end-tidal carbon dioxide; HME: heat and moisture exchange; RR: respiratory rate.
* If using a Mapleson breathing system (rare in United States), CO2 rebreathing is normal. Very high anesthesia machine fresh gas flow may be necessary to decrease both inspired CO2 and ETCO2, especially if the patient is a large adult.
¶ High inspired CO2 may be an artifact if RR >30 breaths/minute. (High RR causes artifacts that include high inspired CO2 readings and low ETCO2 readings when the CO2 monitor cannot track rapid changes, as indicated by a lack of inspiratory and expiratory plateaus in the waveform.)
Δ Please refer to UpToDate content regarding diagnosis and management of anesthesia machine malfunctions.Do you want to add Medilib to your home screen?