Inhalation anesthetics: a new modality of sedation in ICU

Inhalation anaesthetic agents offer new modalities for sedation of mechanically ventilated patients in the ICU. Drugs administered via inhalation have a rapid onset of action and short recovery period. The desired level of drug action can be achieved rapidly, ranging from a light sedation to that approaching a general anaesthetic. Inhalation anaesthetics can precondition the myocardium against functional depression and infarction following ischemia-reperfusion. These also may protect the fasted liver from early ischemia-reperfusion injury by acting during the reperfusion phase. The Anaesthetic Conserving Device (AnaConDa) is a new device for anaesthetic vapours delivery. AnaConDa is a modified heat and moisture exchanger connected to the breathing circuit at the endotracheal tube. It is intended to be used with isoflurane and sevoflurane delivered by syringe pump. A gas monitor immediately indicates gas concentrations. Adjustments of concentrations can be achieved rapidly. An accurate concentration of inhalation anaesthetic agents can be delivered in ventilators owing appropriate ventilatory functions. Active carbon absorbs inhaled anaesthetics used in this system, and it is not appropriate for use with nitrous oxide. AnaConDa is a single patient device and must be changed every 24 hours.