Multi-site Anesthesia Randomized Controlled STudy of End Tidal Control (Et Control) Compared to Conventional Anesthesia Results (MASTER-Anesthesia Trial)

Subjects using Et Control option; the investigator will use and initiate Et Control after the airway is secured and mechanical ventilation is initiated. Machine log data is collected when the investigator initiates the start of anesthesia case on the Aisys CS2. Adjustments to the anesthesia machine settings, discontinuation of use of the investigational Et Control option, and changes to treatment are based upon clinician judgment for the wellbeing of the subject. The clinician must continuously monitor measured inspired and end tidal oxygen and anesthetic concentrations to assess individual responses and compare to the target concentrations.

Subjects to undergo a surgical procedure with inhaled anesthesia meeting the American Society of Anesthesiologists status classification system 1-3. Subjects using conventional option; the investigator will use their conventional means to adjust the vaporizer and mixer, and monitor the patient gas concentrations with the legally marketed Aisys CS2 anesthesia machine without the investigational Et Control feature. Machine log data collection will end, when an "end case" is confirmed on the Aisys CS2 at the end of the anesthesia case.