The system and method of the present application predicts if there is sufficient CO2 absorbent capacity for the next anesthesia case. If insufficient, the canister can be preemptively replaced when no patient is connected to the breathing system. Such prediction also allows clinicians to determine if the CO2 canister has to be changed during the present case or to wait until the end of the case. In the latter, the clinician may buy time by increasing the fresh gas flow rate to reduce the amount of patient CO2 gases recirculated. A predictive estimation of CO2 breakthrough allows more time to prepare for an orderly CO2 canister replacement during a quiet period in the anesthesia care.