Although anaesthesia has become much safer over the years, it is still not perfect. The introduction of propofol in the 1980s and subsequent development of TCI was a major breakthrough. The development of remifentanil has now also given us an alternative to nitrous oxide. Besides this, however, there have been disappointingly few new drug developments in anaesthesia. A number of new formulations of propofol have been developed in an attempt to reduce its side effects (propofol infusions are associated with acidosis and multi-organ failure in children and occasionally in adults).