Faut-il encore utiliser le protoxyde d'azote en anesthésie ?

Nitrous oxide has limited anaesthetic potency. It shortens the duration of anaesthetic induction due to a second gas effect. It is commonly used in a 60 to 70% mixture in oxygen to maintain an adequate depth of anaesthesia in combination with halogenates or intravenous anaesthetics, but its hypnotic and opioid agents' sparing effect is limited. The use of N2O also results in side effects: N2O produces a two fold increase in the risk of postoperative nausea and vomiting. N2O reduces methionine-synthase activity, which plays a role in DNA, RNA, and myelin and catecholamine synthesis. It is consequently contra-indicated in patients suffering from Biermer anaemia, bowel diseases, alcoholism, and in aged and malnourished patients. N2O induces an increase in homocystein, which is a risk factor of cardiovascular disease. Administration of high FiO2 concentration without N2O has been reported to decrease the incidence of postoperative infectious and major complications and to improve surgical wound healing.