- A neurologic or pharmacologic state in which painful stimuli are so moderated that, though still perceived, they are no longer painful. Cf.:anesthesia. [G. insensibility, fr. an- priv. + algesis, sensation of pain]- inhalation a. a. produced by inhalation of a central nervous system depressant gas (especially nitrous oxide) or vapor.- patient-controlled a. (PCA) a method for control of pain based upon a pump for the constant intravenous or, less frequently, epidural infusion of a dilute narcotic solution that includes a mechanism for the self-administration at predetermined intervals of a predetermined amount of the narcotic solution should the infusion fail to relieve pain. SYN: outpatient anesthesia, patient-controlled anesthesia.
* * *
* * *n.reduced sensibility to pain, without loss of consciousness and without the sense of touch necessarily being affected. The condition may arise accidentally, if nerves are diseased or damaged, or be induced deliberately by the use of pain-killing drugs (see analgesic). Strictly speaking, local anaesthesia should be called local analgesia. See also relative analgesia.
* * *an·al·ge·sia (an″əl-jeґze-ə) [an-1 + algesia] 1. absence of sensibility to pain; absence of pain on noxious stimulation. 2. the relief of pain without loss of consciousness.
Medical dictionary. 2011.