In some traumatic surgical procedures on the body surface, some anesthetic is often applied to relieve the pain of the patient, and the absorption of the skin is needed to play a good role. So how long to apply anesthetic is a key issue, and the site has a certain relationship, if some of the skin is relatively thin location, such as the eyelids to apply about 15 minutes, can achieve a good effect. But if it is applied to some thicker skin locations, such as the back for 15 minutes, may not achieve the best results, so you need to increase the time to apply the anesthetic, it is recommended that it can be about half an hour. In addition, if the skin is moistened and warmed before the application of anesthetic, this can promote the absorption of the anesthetic into the skin. You can achieve a better effect in the same time.