Nitrous Oxide — Application in Modern Anesthesia

This review paper shows the controversies of using nitrous oxide in anesthesia of different patient populations. It provides information on nitrous oxide’s potential side effects when used in modern anesthesia during surgery.

The ENIGMA I and ENIGMA II studies showed a significantly increased risk of postoperative nausea and vomiting after nitrous oxide administration. The theory is that nitrous oxide administered at pediatric age may accelerate neuronal apoptosis and lead to cerebral toxicity and behavioral and learning disorders later in life. The side effects associated with the use of nitrous oxide are based on megaloblastic changes associated with vitamin B12 deficiency and reduced methionine synthesis.

In recent years, there have been recommendations to eliminate nitrous oxide from medical use due to its toxicity, possible increase in morbidity and mortality, and adverse environmental effects. Nevertheless, some authors promote its use, mainly because of its analgesic effect. Nitrous oxide can be used for analgesia during epidural catheter placement, labor, and postpartum procedures because it crosses the placenta and is rapidly eliminated in newborns at the onset of respiration. Its widespread use in minor pediatric procedures has been described. Currently, there is insufficient evidence to support or refute the continued use of nitrous oxide in medical practice. Most of the available data show that nitrous oxide is obsolete as an anesthetic gas, which unfortunately reduces the need for its continued use in anesthesia.