Nitrous oxide (N2O) has been used as an anaesthetic agent since 1844. It has two well recognized adverse effects: it oxidizes Co(I) to Co(II) and so inactivates vitamin B12, and its high partial pressure in blood allows it to expand into cavities in the body such as the pleural space. Impairment of the action of vitamin B12 can cause both megaloblastic anaemia and, especially in recreational users of N2O, the syndrome of subacute combined degeneration of the spinal cord. The overall cardiovascular effects in noncardiac surgery seem to be minor. N2O is probably a human teratogen.
aWest Midlands Centre for Adverse Drug Reactions
bDepartment of Anaesthesia and Critical Care, Birmingham, UK
cGreen-Templeton College, Oxford, UK
Correspondence to Robin E. Ferner, MSc, MD, FRCP, City Hospital, Birmingham, B18 7QH, UK. Tel: +44 (0)121 507 5672; e-mail: email@example.com
Editor: R E Ferner, MSc, MD, FRCP, Director of the West Midlands Centre for Adverse Drug Reaction Reporting and Consultant Physician at City Hospital, Birmingham, UK. Assistant Editor: Mr C Anton, MA, MEng. Editorial Board: Australia: Dr M Kennedy, Professor G M Shenfield, Denmark: Professor J S Schou; England: Dr J K Aronson; India: Professor N Gogtay; Netherlands: Professor C J van Boxtel, Dr B H Ch Stricker; New Zealand: Dr T Maling; Scotland: Dr D N Bateman; Wales: Professor P A Routledge.