The two hypnotic agents currently used for the maintenance of general anesthesia during cardio-pulmonary bypass (CPB) are propofol and sevoflurane. Propofol can be administered directly in the cardiotome of the CPB while sevoflurane is administered through the CPB’s oxygenator¹.

Both agents have environmental concerns, and, as far as we know, the carbon footprint of those two agents are equivalent². But, to do so, anesthesiologists have to be very cautious when using sevoflurane. One of the main issues is to maintain a fresh gas flow ≤0.5 liter per minute². This condition cannot be met while on CPB. To insure a 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, Allemagne) 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 of particular interest because the gas captured by the device can be extracted, retreated and, potentially re-used (pending a regulatory and legal approval).