Patient Safety Presentation

Nitrous Oxide: Vitamin B12 Destruction and Myeloneuropathy

Kirk Hogan, MD, JD

Presented September 5th, 2018 at APSF Stoelting Conference 2018


  • Nitrous oxide is the only inhaled anesthetic that kills every person exposed for 5-7 days via specific toxicity to the single carbon metabolism pathway that was discovered decades after the FDA was legislated into being.
  • The safety of nitrous oxide resides in its duration of use, each patient’s intracellular functional reserves of methionine, and their inborn and acquired susceptibilities.
  • Multiple reports irrefutably indicate that nitrous oxide in concentrations and durations used in clinical anesthetic practice is a “nerve gas” in susceptible patients.
  • Nitrous oxide impairs regeneration of neurons after sharp and blunt injury to the nervous system.
  • Nitrous oxide has no benefits over equipotent doses of contemporary inhaled anesthetics other than more rapid induction and emergence when used for 3-5 minutes at the beginning and at the end of a surgical procedure, and safety in patients at risk for malignant hyperthermia (MH).
  • During nitrous oxide use for labor and delivery, children with prevalent inborn errors of single carbon metabolism (20%) and third trimester cobalamin deficiency (20%) are exposed to high concentrations of nitrous oxide for durations well in excess of those needed to inactivate methionine synthase and its cobalamin co-factor.
  • The comparative safety of nitrous oxide in labor and delivery has never been investigated.
  • Parents of children exposed to nitrous oxide during labor and delivery are not informed of the risks of nitrous oxide.


Nitrous Oxide Vitamin B12 Destruction and Myeloneuropathy – [PDF]


Kirk Hogan, MD, JD

Kirk Hogan, MD, JD

Dr. Kirk Hogan is a professor of anesthesiology at the University of Wisconsin – Madison, WI. The focus of his research is the identification of genomic and epigenomic predictors of deleterious consequences of anesthetics and surgery on the central nervous system, skeletal muscle, and other tissues. He serves as the scientific director responsible for biomarker characterization of DNA samples for The Wisconsin Registry for Alzheimer’s Prevention (WRAP). His report of acute neurologic injury after nitrous oxide anesthesia is the first example of a “two-hit”, pathway-specific, pharmacogenetic mechanism in which a mutation is expressed in an enzyme upstream of a target protein that is impaired by a drug.