Xenon washout during in-vitro extracorporeal circulation using different oxygenators

Area of Science:

• Anesthesiology
• Cardiovascular Surgery
• Medical Engineering

Background:

• Xenon anesthesia preserves myocardial contractility and cardiocirculatory function, even in compromised patients.
• Its potential benefits for cardiac surgery patients undergoing extracorporeal circulation (ECC) are hindered by potential xenon loss.
• Investigating xenon diffusion through oxygenators is crucial to assess its feasibility during ECC.

Purpose of the Study:

• To determine if common oxygenators used in extracorporeal circulation (ECC) allow xenon to diffuse through.
• To quantify xenon loss during ECC when using standard oxygenators.
• To evaluate the practicality of using xenon anesthesia during ECC.

Main Methods:

• An in-vitro extracorporeal circulation (ECC) model was used with xenon-saturated blood.
• Eight experiments were conducted, testing four different common oxygenators.
• Continuous mass spectrometry at the exhaust port measured xenon concentrations in expired gas.

Main Results:

• Xenon concentrations peaked at the oxygenator exhaust within one minute of ECC initiation.
• No measurable xenon was detected in the expired gas two minutes after ECC onset.
• Common oxygenators effectively eliminate xenon during ECC.

Conclusions:

• Standard oxygenators lead to significant xenon elimination into the atmosphere during ECC.
• Maintaining xenon anesthesia during ECC would require continuous, costly gas application to offset losses.
• Current oxygenators and ECC equipment are not practical for xenon anesthesia in cardiac surgery.