loss of sensation in a region of the body produced by application of an anesthetic agent to all the nerves supplying that region (as when an epidural anesthetic is administered to the pelvic region during childbirth)是什么意思 loss of sensation in a region of the body produced by application of an anesthetic agent to all the nerves supplying that region (as when an epidural anesthetic is administered to the pelvic region during childbirth)怎么读