A new device to reduce the consumption of a halogenated anaesthetic agent

We report the first clinical application of a new anaesthetic agent-saving device. The principles of a heat-moisture exchanger have been further developed to create a device that reduces inhalational agent consumption. Sixteen patients were randomly allocated to receive isoflurane through either a vaporiser or through the agent-saving device. A coaxial Mapleson D system (Bain) was used in both groups. A standard ventilatory setting was used, aiming for normocapnia. Mean (SD) isoflurane consumption was 24.5 (2.8) ml.MAC-hour(-1) with the vaporiser, compared with 15.2 (3.0) ml.MAC-hour(-1) with the new device (p < 0.05). This corresponded to a 40% saving in the consumption of isoflurane. The amount of isoflurane that was scavenged to the atmosphere was reduced by an average of 55%.