Is there a need for a new inhalational anaesthetic agent?

New anaesthetic agents are continually being developed in an effort to prepare the ideal agent. Isoflurane is the first choice of many anaesthetists, although it clearly falls short of the ideal on a number of counts. The need and place for any new agent depends on comparing the properties of a theoretically ideal agent with those of isoflurane and the new agent. Desflurane is a step towards a more ideal inhaled agent; however, there is still the need to synthesise and evaluate new chemical entities in order that the ideal can more nearly be approached.