[Critical evaluation of the new inhalational anesthetics desflurane and sevoflurane]

New anaesthetic agents are being continuously developed to find the ideal agent. The most commonly used inhaled anaesthetic in adults is isoflurane and in children halothane. The need for, and the value of the new agents desflurane and sevoflurane depend on a comparison of the properties of a theoretically ideal agent with those of isoflurane, halothane and the new agents. Therefore, the following topics are discussed in the overview: pharmacokinetic properties, recovery parameters, mask induction in adults, paediatric anaesthesia, metabolism, stability in carbon dioxide absorbents and cardiovascular effects. Desflurane and sevoflurane may be considered a step toward the ideal inhalational agents. Both possess the advantage of rapid recovery from surgical anesthesia. Desflurane has a major advantage over sevoflurane: it is not biotransformed nor does it interact with carbon dioxide absorbents. However, desflurane is associated with troublesome cardiovascular stimulation involving tachycardia and both pulmonary and systemic hypertension. Sevoflurane appears to be advantageous for three reasons: firstly, because of its pleasant odour and consequent suitability for induction by inhalation, particularly in paediatric anaesthesia; secondly, it can be used with currently employed vaporizers, and thirdly, surgical demands can be met by lower doses, because its potency is higher.