Abstract
For the purpose of relieving the patients of the anxiety, the fear and the pain on endoscopic examination, we tried to use the premixed gas made up of 50% nitrous oxide and 50% oxygen in 54 cases. We convinced that this method was effective in 70% of the cases and had little side effect. We conclude the practical application of this prexmied gas will be useful for doctors who have little knowledge of the anesthesia by the reasons of its saf etiness and covenience.