spinal anesthesia [L, spina, backbone; Gk, anaisthesia, lack of feeling] , a state of lack of sensation in the lower part of the body produced by injection of a local anesthetic drug into the subarachnoid cerebrospinal fluid space. May be combined with narcotics such as preservative-free morphine, and/or Fentanyl for postoperative analgesia. Also called subarachnoid block anesthesia. See also anesthesia, regional anesthesia.
