Over 300 million patients annually undergo surgery worldwide, with inhaled anesthetic agents costing approximately $1.2 billion yearly. Automating anesthesia delivery could reduce these costs while decreasing waste, emissions, and clinician errors. GE Healthcare developed end-tidal control software to advance automatic anesthetic administration.
The software monitors and automatically adjusts anesthetic concentrations in closed-circuit systems within a 0.5-10 liters per minute flow range. Providers set target end-tidal oxygen and anesthetic concentrations plus minimum flow rates. "The system thereafter monitors these by regularly sampling gas in the breathing circuit after every breath," using "a proprietary algorithm to automatically adjust fresh gas flow and anesthetic concentrations."
The system includes a carbon dioxide absorber for safe gas rebreathing and employs negative feedback control. However, exact calculations remain proprietary. The software is available standalone or integrated into Aisys CS2 and Carestation systems, having received CE marking in 2013 and 2011.
Safety features include system monitoring, fresh gas sampling every 3 minutes, leak detection with automatic increased fresh gas flow response, and an end-tidal control supervisor monitoring oxygen and anesthetic delivery. "If the supervisor detects a system failure, the software automatically and immediately exits end-tidal control mode." Manual re-entry requires resolving calibration issues. All operations generate documented logs.
Contraindications include face mask airways, halothane use, non-closed circuits, cardiac bypass, and procedures risking lung damage or requiring 100% oxygen avoidance. Minimum respiratory rates of 35 breaths per minute are required.
The software reduces emissions and costs by minimizing waste and improving workflow efficiency. The FDA granted premarket approval following multi-center, multi-year U.S. trials involving over 200 patients comparing it to conventional methods.