Nitrous Oxide (Laughing Gas)

Nitrous oxide has been used for anesthesia in dentistry since the 1800s. The most common use is as a 50:50 mix with oxygen, commonly known as Entonox or Nitronox delivered through a demand valve, and frequently used to relieve pain associated with childbirth, trauma and heart attacks.

Professional use can involve constant supply flowmeters which allow the proportion of nitrous oxide and the combined gas flow rate to be individually adjusted. Nitrous oxide is typically administered by dentists through a demand-valve inhaler over the nose that only releases gas when the patient inhales through the nose.