[Theory and practice of low-flow anaesthesia]

The article depicts the history of inhalation anesthesia and closed system anesthesia. Closed or almost closed anesthesia systems have been in use since 1850. At that time, the anesthetic agent was chloroform. It was administered via a closed system, where potassium hydroxide was utilized as a carbon dioxide scavenger. However, that kind of CO2 absorption method did not gain acceptance. Later, a quick and effective method of carbon dioxide absorption was developed when the first soda-lime absorber was introduced in 1917. In the mid 1950's, when halothane was brought forth, the use of low-flow and closed circle system anesthesia diminished significantly. This was largely due to the inherent problem in the first generation halothane vaporizers, which was the unreliable delivery of vapor at low fresh gas flows. Introduction of isoflurane in the early 1980's, gave way to a renewed interest in low flow and closed circuit anesthesia. It was further enhanced by the fact that anesthetic agents are atmospheric pollutants, especially nitrous oxide, halothane, enflurane, and to some extent isoflurane. The introduction of new low solubility agents, like desflurane and sevoflurane, have initiated a renaissance in the use of low-flow anesthesia, in order to contain costs associated with adapting fresh gas flows to patient demand.