Anesthesia is formed through administering drugs into body through air passage or injection. The anesthesia that is carried out through air passage or injection does not reach the stomach, and it is not regarded as eating or drinking.  However, in regional and general anesthesia, in emergencies, medicine, liquid and serum are administered through vascular access. Therefore, local anesthesia does not invalidate fasting. In regional and general anesthesia, fasting is invalidated because serum is administered.