[Nitrous oxide. Sense or nonsense for today's anaesthesia].

Nitrous oxide has been used in addition to other volatile anaesthetics to provide general anaesthesia and short time sedation for more than 150 years. However, the exact mechanisms of action remain unclear. For decades nitrous oxide was considered to be the ideal anaesthetic because of his favourable physical properties and low cardiovascular side effects. However, the known side effects of nitrous oxide as well as the implementation of new anaesthetic agents and short acting opiates led to more and more criticism about the administration of this gas. Nitrous oxide is still frequently used for mask induction primarily in paediatric anaesthesia and gynaecology. However, recent studies have shown that omitting nitrous oxide can also be a risk factor because of an increased susceptibility to intraoperative awareness. Careful consideration of the illustrated contraindications and side effects as well as the available alternatives, shows that nitrous oxide is still an option in general anaesthesia.