Ascorbic acid (AsA) and dehydroascorbic acid (DHA) in plasma, and the total vitamin C (AsA + DHA) in urine after oral surgery were measured to investigate whether general anesthesia has effects on the level of plasma AsA. Plasma AsA decreased significantly on the 1st and 3rd post-operative day in the general anesthesia group, but not in the local anesthesia group. A decrease in the AsA level was seen in both the halothane group and the neuroleptanesthesia group. Plasma DHA was not detected pre-operatively, but increased post-operatively and the total vitamin C in the urine decreased on the 1st post-operative day in the general anesthesia group.
It was concluded that general anesthesia caused a decrease in the plasma AsA level. This can be only partially explained by the oxidation of AsA.
We are going to investigate other causes as the degree of decrease of AsA was larger than the degree of increase of DHA.