Evaluation of high inspired CO₂ during ventilation with an anesthesia workstation

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.)