Rebreathing of Carbon Dioxide With a Device Used for Giving Inhalational Anaesthesia

Dead Space Effect of an Anaesthesia Gas Reflector (AnaConDa)

The anesthesia gas reflector (AnaConDa) is built on the adsorptive capacity of active carbon which also adsorbs carbon dioxide in exhaled air. Rebreathing of carbon dioxide thus occurs and must be compensated for by increased ventilation. This study aims at determining how much compensation must be given, based on the hypothesis that rebreathing depends on carbon dioxide level in blood and exhaled air.

Inclusion Criteria:

• elective coronary artery by-pass graft surgery
• elective valve replacement surgery
• normal left ventricular ejection fraction on preoperative echocardiography

Exclusion Criteria:

• obstructive lung disease
• restrictive lung disease