Nitrous Oxide

What is Nitrous Oxide?

• Inhalational agent used for general anesthetic induction. Combined with other drugs to augment an anesthetic and analgesic effect.

Mechanism of Action & Pharmacokinetics ¹²

• Nitrous oxide exhibits non-competitive inhibitive effects on the NMDA receptors in the CNS for an anesthetic effect.
• Analgesic effects are through a release of endogenous opioids acting on opioid receptors.
• By acting on GABA-A receptors, nitrous oxide also exhibits anxiolytic properties.

Pharmacodynamics ^{1 2 34}

Cardiovascular

• Mildly increases heart rate secondary to slight adrenergic stimulation.

  Respiratory

• There is minimal effect on minute ventilation.
• Compared to other agents, it does not cause bronchodilation.

  Central Nervous System

• Acts on receptors in the CNS - NMDA, GABA-A, Mu opioid receptors.
• Increases cerebral blood flow, cerebral metabolic rate and intracranial pressure.

Indications ^{1 3}

Anesthetic Indications

• Can be mixed in with volatile agents like DrugLibrary/Sevoflurane

  Sevoflurane Private or Broken Links The page you're looking for is either not available or private! for Induction of General AnesthesiaInduction of General Anesthesia Introduction The start of a case represents one of the highest risk periods in the operation. After a surgical time-out, the tools required for a safe induction can be remembered with the MDSOLES ... and will speed the onset of anesthesia

Other Indications

• Anxiolytic agent for procedures, i.e. dental procedures, labour. Delivered via nasal mask along with oxygen.

Complications ^{1 3 4}

• Can lead to cardiovascular depression in patients with prior myocardial dysfunction or patients in shock.
• FiO2 of delivered gas must be reduced to administer nitrous oxide, which will lead to less pre-oxygenation
• Diffusion hypoxia can occur once nitrous oxide delivery is stopped as it can dilute the oxygen held in the alveoli by releasing nitrous oxide stores in the body.
• There is an increased risk of postoperative nausea and vomiting associated with use of nitrous oxide.

References