Reste-t-il une place pour le protoxyde d’azote en anesthésie ?

Nitrous oxide (N₂O) is the oldest anesthetic drug. Despite its low anaesthetizing power and emetic effects, its analgesic, anti-hyperalgesic and anxiolytic properties, rapid kinetics, ease of administration and acceptance by patients have earned it a place in the pharmacopoeia both in and out of the OR. However, its use has declined drastically in recent years, in tandem with the emergence of new molecules and awareness of its ecological cost. With a lifetime of 116 years in the atmosphere, a global warming potential of 265, and an ozone depletion potential of 0.017, it is now the 3rd largest greenhouse gas and the main ozone-depleting substance. Medical N₂O accounts for 1% of healthcare-related pollution in Europe. The use of N₂O must therefore be considered as part of an overall project to eco-design healthcare and decarbonize the healthcare sector. Although it still has rare and elective indications, such as assisting in childbirth or performing short, painful procedures particularly in paediatrics, its use must be rationalized, and alternatives encouraged. Restricting its use, training staff in its use, and combating leaks are key elements in reducing its environmental impact. The dismantling of N₂O pipelines in favor of cylinders connected to the respirator if necessary, and the construction of nitrous oxide-free OR are the currently recommended by the SFAR.