Figure 1. The Sedaconda Anaesthetic Conserving Device-S (Sedaconda ACD-S) is a small, disposable volatile anaesthetic agent delivery and reflection system capable of administering isoflurane to mechanically ventilated patients. Standard placement is integrated into the ventilator circuit in place of the commonly used passive heat and moisture exchanger, between the patient’s endotracheal tube or tracheostomy and the Y-piece of the ventilator tubing. The evaporator is a porous plastic rod with a large surface area that vaporises isoflurane with the airflow. Isoflurane exhaled by the patient enters the reflection medium, is absorbed to the active carbon filter, and is desorbed and returned to the patient in the next breath with approximately 90% reflection. The syringe is a standard 50–60 mL syringe with a unique connector system to prevent unintentional intravenous administration. Sedation depth is adjusted by increasing or decreasing the syringe pump rate. A FlurAbsorb active carbon filter is used to scavenge the small amounts of exhaled isoflurane not reflected by the ACD-S device to create a closed administration circuit. End-tidal carbon dioxide (CO₂) concentration is measured with standard gas analyser and presented with capnography. ICU, intensive care unit.