Premium
Pre‐operative vitamin B infusion and prevention of nitrous oxide‐induced homocysteine increase
Author(s) -
Rao L. K.,
Francis A. M.,
Wilcox U.,
Miller J. P.,
Nagele P.
Publication year - 2010
Publication title -
anaesthesia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.839
H-Index - 117
eISSN - 1365-2044
pISSN - 0003-2409
DOI - 10.1111/j.1365-2044.2010.06375.x
Subject(s) - nitrous oxide , homocysteine , medicine , placebo , vitamin , vitamin b12 , anesthesia , cyanocobalamin , b vitamins , methionine , surgery , endocrinology , biochemistry , chemistry , alternative medicine , amino acid , pathology
Summary Nitrous oxide inactivates vitamin B 12 with detrimental consequences for folate and methionine metabolism, detectable by an increase in total plasma homocysteine. We hypothesised that a pre‐operative vitamin B 12 and folate infusion prevents nitrous oxide‐induced homocysteine increase. Sixty‐three healthy patients having elective surgery were randomly allocated to receive either B‐vitamin plus nitrous oxide; placebo plus nitrous oxide or placebo plus air. Fifty‐nine patients completed the study. After intravenous B‐vitamin infusion, plasma vitamin B 12 and folate concentrations increased 35‐fold and 12‐fold, respectively, on the first postoperative measurement. Patients who received B‐vitamins developed a similar increase (18%) in homocysteine after nitrous oxide (1.9 μmol.l −1 ; 95% CI 0.2–3.6 μmol.l −1 ) as those who did not (22%; 2.7 μmol.l −1 ; 95% CI 0.6–4.8 μmol.l −1 ). Patients not receiving nitrous oxide had no homocysteine change (0.5 μmol.l −1 ; 95% CI −0.8–1.9 μmol.l −1 ), indicating that pre‐operative intravenous B‐vitamins may not prevent nitrous oxide‐induced hyperhomocysteinaemia.