of nerves . Two frequently used regional anesthesia are spinal anesthesia and epidural anesthesia . General anesthesia describes unconsciousness and lack of any awareness or sensation . [ 2 ] Contents 1 History 1.1 Plant derivatives 1.2 Early inhalational anesthetics 1.3 Non-pharmacological methods 2 Anesthesia providers 2.1 Physicians 2.2 Nurse anesthetists