Fig. 1.

a Mirus™ device. b Setup of the Mirus™ system: the interface (“Mirus™ Exchanger”) is inserted between the Y-piece (1) and the endotracheal tube (2). The interface is connected with the control unit by a multi-lumen cable (blue line). An active anaesthesia gas scavenging system (black arrow) connected to the vacuum system is provided by the manufacturer. c Setup of the AnaConDa™: the AnaConDa™ is inserted between the Y-piece (1) and the endotracheal tube (2). Liquid isoflurane or sevoflurane is administered by a syringe pump into a hollow rod (“Evaporator”). An external gas monitor must be used. Active and passive scavenging systems are available and should be connected to the gas outlet of the ventilator (black arrow). Sample gas should also be scavenged. d Wash-out kinetics of desflurane (blue) and isoflurane (purple) over 20 min in the same patient after 24-h application. The end-tidal desflurane concentration decreases down to 20 % of the initial concentration (C₀; 3.8 vol%) after 1 min; the isoflurane concentration only decreases to 50 % of C₀ (0.8 vol%) during the whole observation period. The patient first responded after 5.08 min at 0.7 vol% desflurane and after 17 min at 0.44 vol% isoflurane