The 2 hypnotic agents currently used for the maintenance of general anesthesia during cardiopulmonary bypass (CPB) are propofol and sevoflurane. Propofol can be administered directly into the cardiotome of the CPB, whereas sevoflurane is administered through the CPB’s oxygenator.

Both agents have environmental concerns, and, as far as we know, the carbon footprint of those 2 agents is equivalent.

But, to obtain an equivalent carbon footprint with propofol or sevoflurane, anesthesiologists must be very cautious when using sevoflurane. One main issue is maintaining a fresh gas flow of ≤0.5 liters per minute.

This condition cannot be met while on CPB. To ensure good gas exchange, the gas flow through the CPB oxygenator should be approximately equal to the CPB output (2.4 L min⁻¹m⁻² for an adult patient under normothermic conditions).

CONTRAfluran (ZeoSys Medical Gmbh, Luckenwalde, Germany) is a gas-capture system. It contains a unique adsorbent that captures 99% of the sevoflurane or desflurane contained in the exhaled gases. It has been developed to prevent the release of these volatile anesthetic gases into the operating room and atmosphere. It is particularly interesting because the gas captured by the device can be extracted, retreated, and potentially reused (pending regulatory and legal approval).

It consists of a canister to capture the anesthetic gases and a sensor (SENSOfluran, ZeoSys Medical Gmbh) indicating when the canister is saturated.

In a global approach to reducing our environmental impact, we wanted to test the possibility of adapting a CONTRAfluran device on the outlet of a CPB oxygenator and to evaluate the installation’s safety and efficiency.

For ethical and economic reasons, we conducted this pilot study on a bench to test the oxygenation, decarboxylation, and safety of the CPB circuit we use daily, equipped with a CONTRAfluran device (Fig 1), trying to mimic as closely as possible our clinical practice.