- : Loss of feeling or awareness. A local anesthetic causes loss of feeling in a part of the body. A general anesthetic puts the person to sleep.
* * *1. Loss of sensation resulting from pharmacologic depression of nerve function or from neurologic dysfunction. 2. Broad term for anesthesiology as a clinical specialty. [G. anaisthesia, fr. an- priv. + aisthesis, sensation]- acupuncture a. percutaneous insertion of, and stimulation by, needles placed in critical areas of the body to produce loss of sensation in another area.- axillary a. loss of sensation in the distal two-thirds of the upper extremity following injection of a local anesthetic solution about the nerve trunks in the axilla.- balanced a. a technique of general a. based on the concept that administration of a mixture of small amounts of several neuronal depressants summates the advantages, but not the disadvantages of, the individual components of the mixture.- basal a. parenteral administration of one or more sedatives to produce a state of depressed consciousness short of a general a..- brachial a. anesthetization of an upper extremity by injection of local anesthetic solution about the brachial plexus.- caudal a. regional a. by injection of local anesthetic solution into the epidural space via the sacral hiatus.- cervical a. regional a. of the neck by injection of a local anesthetic solution about the cervical nerves or into the cervical epidural space.- circle absorption a. inhalation a. in which a circuit with carbon dioxide absorbent is used for complete (closed) or partial (semiclosed) rebreathing of exhaled gases.- closed a. inhalation a. in which there is total rebreathing of all exhaled gases, except carbon dioxide which is absorbed; gas flow into the anesthetic circuit consists only of oxygen, in amounts equal to the patient's metabolic consumption, plus small amounts of other gases ( e.g., nitrous oxide) that undergo continued uptake by and distribution in the patient.- conduction a. regional a. in which local anesthetic solution is injected about nerves to inhibit nerve transmission; includes spinal, epidural, nerve block, and field block a., but not local or topical a.. SYN: block a..- continuous epidural a. insertion of a catheter into the lumbar or caudal epidural space for the repeated injection of local anesthetic solutions as a means of prolonging duration of a.. SYN: fractional epidural a..- continuous spinal a. insertion of a catheter into the spinal subarachnoid space and leaving it in situ to permit serial intermittent injection of local anesthetic solution for prolonged spinal a.. SYN: fractional spinal a..- dental a. general, conduction, local, or topical a. for operations upon the teeth, gingivae, or associated structures.- differential spinal a. a form of diagnostic spinal a. producing blockade of different types of nerves in the subarachnoid space, based upon their differences in sensitivity to local anesthetics; also observed during surgical spinal a..- dissociated a. loss of some types of sensation with persistence of others; most often used in context of nerve blocks, wherein a loss of sensation for pain and temperature occurs without loss of tactile sense.- dissociative a. a form of general a., but not necessarily complete unconsciousness, characterized by catalepsy, catatonia, and amnesia, especially that produced by phenylcyclohexylamine compounds, including ketamine.- electric a. a., usually general a., produced by application of an electrical current.- endotracheal a. inhalation a. technique in which anesthetic and respiratory gases pass through a tube placed in the trachea via the mouth or nose. SYN: intratracheal a..- epidural a. regional a. produced by injection of local anesthetic solution into the peridural space. SYN: peridural a..- extradural a. anesthetization, by local anesthetics, of nerves near the spinal canal external to the dura mater; often refers to epidural a., but may include paravertebral a..- field block a. conduction a. in which small nerves are not anesthetized individually, as in nerve block a., but instead are blocked en masse by local anesthetic solution injected to form a barrier proximal to the operative site.- general a. loss of ability to perceive pain associated with loss of consciousness produced by intravenous or inhalation anesthetic agents.- high spinal a. spinal a. in which the level of sensory denervation extends to the second or third thoracic dermatome.- hyperbaric a. inhalation of depressant gases or vapors at pressures greater than 1 atmosphere, especially as a means of producing general a. with agents too weak to produce a. at 1 atmosphere.- hyperbaric spinal a. spinal a. in which spread of local anesthetic solution in the subarachnoid space is controlled by adjusting the position of the patient when the density of local anesthetic is made greater than the density of cerebrospinal fluid ( i.e., hyperbaric) by the addition of glucose.- hypobaric spinal a. spinal a. in which spread of local anesthetic solution in the subarachnoid space is controlled by adjusting the position of the patient when the density of the local anesthetic solution is made less than the density of cerebrospinal fluid ( i.e., hypobaric) by the addition of distilled water.- hypotensive a. a. in which arterial hypotension is deliberately induced as a means of decreasing operative blood loss.- hypothermic a. general a. administered in conjunction with artificial lowering of body temperature.- hysterical a. a. as a manifestation of hysteria, usually involving the surface areas of the body not conforming to neuroanatomic distribution.- infiltration a. a. produced by injection of local anesthetic solution directly into an area that is painful or about to be operated upon.- insufflation a. maintenance of inhalation a. by delivery of anesthetic gases or vapors directly to the airway of a spontaneously breathing patient.- intercostal a. regional a. produced by injection of local anesthetic solution about intercostal nerves.- intramedullary a. rarely used method of general a. by injection of intravenous anesthetic agent(s) into the medullary canal of long bones. SYN: intraosseous a..- intranasal a. 1. insufflation a. in which an inhalation anesthetic is added to inhaled air passing through the nose or nasopharynx; 2. a. of nasal passages by infiltration and topical application of local anesthetic solution to nasal mucosa.- intraoral a. 1. insufflation a. in which an inhalation anesthetic is added to inhaled air passing through the mouth; 2. regional a. of the mouth and associated structures when local anesthetic solutions are used by topical application to oral mucosa, by local infiltration, or as nerve blocks.- intraspinal a. inaccurate synonym for spinal a.; local anesthetic solutions are not injected into the spinal cord.- intratracheal a. SYN: endotracheal a..- intravenous a. general a. produced by injection of central nervous system depressants into the venous circulation.- intravenous regional a. regional a. by intravenous injection of local anesthetic solution distal to an occlusive tourniquet in an extremity previously exsanguinated by pressure or gravity. SYN: Bier method (1).- isobaric spinal a. spinal a. of same density as cerebrospinal fluid so that the level of a. is not influenced by a change in the position of the patient.- local a. a general term referring to topical, infiltration, field block, or nerve block a. but usually not to spinal or epidural a.. SEE ALSO: local anesthetics, under anesthetic.- low spinal a. spinal a. in which the level of sensory denervation extends to the tenth or eleventh thoracic dermatome.- nerve block a. conduction a. in which local anesthetic solution is injected about nerves, nerve trunks, or nerve plexuses.- nonrebreathing a. a technique for inhalation a. in which valves exhaust all exhaled air from the circuit.- open drop a. inhalation a. by vaporization of a liquid anesthetic placed drop by drop on a gauze mask covering the mouth and nose.- outpatient a. SYN: patient-controlled analgesia.- painful a. SYN: a. dolorosa.- paracervical block a. regional a. of the cervix uteri by injection of local anesthetic solution into tissues adjacent to the cervix.- paravertebral a. 1. a. by injection of local anesthetic solution about nerves as they exit from the vertebral canal; 2. combined presynaptic, postsynaptic, and ganglionic sympathetic block by injection of local anesthetic solution about paravertebral sympathetic chains.- patient-controlled a. (PCA) SYN: patient-controlled analgesia.- presacral a. injection of local anesthetic solution anterior to the sacrum, to block nerves as they exit from the sacral foramina.- pudendal a. local a. produced by blocking the pudendal nerves near the spinal processes of the ischium; used in obstetrics.- rebreathing a. a technique for inhalation a. in which a portion or all of the gases that are exhaled are subsequently inhaled after carbon dioxide has been absorbed.- rectal a. general a. produced by instillation into the rectum of a solution containing a central nervous system depressant.- regional a. use of local anesthetic solution(s) to produce circumscribed areas of loss of sensation; a generic term including conduction, nerve block, spinal, epidural, field block, infiltration, and topical a.. SYN: conduction analgesia.- retrobulbar a. injection of a local anesthetic behind the eye to produce sensory denervation of the eye.- saddle block a. a form of spinal a. limited in area to the buttocks, perineum, and inner surfaces of the thighs.- spinal a. 1. loss of sensation produced by injection of local anesthetic solution(s) into the spinal subarachnoid space; SYN: subarachnoid a.. 2. loss of sensation produced by disease of the spinal cord.- splanchnic a. loss of sensation in areas of the visceral peritoneum innervated by the splanchnic nerves. SYN: visceral a..- surgical a. 1. any a. administered for the purpose of permitting performance of an operative procedure, as differentiated from obstetrical, diagnostic, and therapeutic a.; 2. loss of sensation with muscle relaxation adequate for an operative procedure.- to-and-fro a. a. using of a valveless closed a. circuit in which respired gases pass back and forth through a carbon dioxide absorbent interposed between patient and respiratory reservoir bag.- topical a. superficial loss of sensation in conjunctiva, mucous membranes or skin, produced by direct application of local anesthetic solutions, ointments, or jellies.- total spinal a. spinal a. extensive enough to produce loss of sensation in all extracranial sensory roots.
* * *an·es·the·sia or chiefly Brit an·aes·the·sia .an-əs-'thē-zhə n1) loss of sensation esp. to touch usu. resulting from a lesion in the nervous system or from some other abnormality2) loss of sensation and usu. of consciousness without loss of vital functions artificially produced by the administration of one or more agents that block the passage of pain impulses along nerve pathways to the brain
* * *an·es·the·sia (an″es-theґzhə) [an-1 + esthesia] 1. loss of sensation, usually by damage to a nerve or receptor; called also numbness. 2. loss of the ability to feel pain, caused by administration of a drug or by other medical interventions; cf. anesthetic (def. 2).
Medical dictionary. 2011.