anesthetic

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anesthetic

 [an″es-thet´ik]
1. pertaining to, characterized by, or producing anesthesia.
2. a drug or agent used to abolish the sensation of pain, to achieve adequate muscle relaxation during surgery, to calm fear and allay anxiety, and to produce amnesia for the event.

Inhalational anesthetics are gases or volatile liquids that produce general anesthesia when inhaled. The commonly used inhalational agents are halothane, enflurane, isoflurane, and nitrous oxide. Older agents, such as ether and cyclopropane, are now used infrequently. The mechanism of action of all inhalational anesthetics is thought to involve uptake of the gas in the lipid bilayer of cell membranes and interaction with the membrane proteins, resulting in inhibition of synaptic transmission of nerve impulses. For surgical anesthesia, these agents are usually used with preanesthetic medication, which includes sedatives or opiates to relieve preoperative and postoperative pain and tranquilizers to reduce anxiety. Neuromuscular blocking agents are used as muscle relaxants during surgery. They include tubocurarine, metocurine, succinylcholine, pancuronium, atracurium, and vecuronium.

Intravenous anesthetics are sedative hypnotic drugs that produce anesthesia in large doses. The most common of these are the phenol derivative propofol and ultra–short acting barbiturates such as thiopental and methohexital; these can be used alone for brief surgical procedures or for rapid induction of anesthesia maintained by inhalational anesthetics.

Other intravenous methods of anesthesia are neuroleptanalgesia, which uses a combination of the butyrophenone tranquilizer droperidol and the opioid fentanyl; neuroleptanesthesia, which uses neuroleptanalgesia plus nitrous oxide; and dissociative anesthesia, which uses ketamine, a drug related to the hallucinogens that produces profound analgesia.

Local anesthetics are drugs that block nerve conduction in the region where they are applied. They act by altering permeability of nerve cells to sodium ions and thus blocking conduction of nerve impulses. They may be applied topically or injected into the tissues. The first local anesthetic was cocaine. Synthetic local anesthetics are all given names ending in -caine; examples are procaine and lidocaine.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

an·es·thet·ic

(an'es-thet'ik),
1. A compound that reversibly depresses neuronal function, which produces loss of ability to perceive pain and/or other sensations.
2. Collective designation for anesthetizing agents administered to a person at a particular time.
3. Characterized by loss of sensation or capable of producing loss of sensation.
4. Associated with or owing to the state of anesthesia.
Farlex Partner Medical Dictionary © Farlex 2012

anesthetic

also

anaesthetic

(ăn′ĭs-thĕt′ĭk)
adj.
1. Relating to or resembling anesthesia.
2. Causing anesthesia.
3. Insensitive.
n.
1. An agent that causes loss of sensation with or without the loss of consciousness.
2. Something likened to this in effect: For some people watching television is an anesthetic for the mind.

an′es·thet′i·cal·ly adv.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

anesthetic

adjective
1. Producing, referring or pertaining to, or characterized by anesthesia.
2. Characterized by a loss of sensation or awareness; numbness noun An agent or drug that abolishes the sensation of pain or awareness of surroundings. See General anesthetic, Inhalation anesthetic, Local anesthetic, Opioid anesthetic.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

an·es·thet·ic

(an'es-thet'ik)
1. A compound that depresses neuronal function, producing loss of ability to perceive pain and/or other sensations.
2. Collective designation for anesthetizing agents administered to a person at a particular time.
3. Characterized by loss of sensation or capable of producing loss of sensation.
4. Associated with or due to the state of anesthesia.
Synonym(s): anaesthetic.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

Anesthetic

Medicine that causes a loss of feeling, especially of pain. Some anesthetics also cause a loss of consciousness.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.

an·es·thet·ic

(an'es-thet'ik)
1. Agent or compound that reversibly depresses neuronal function, which produces loss of ability to perceive pain and/or other sensations.
2. Characterized by loss of sensation or capable of producing loss of sensation.
Synonym(s): anaesthetic.
Medical Dictionary for the Dental Professions © Farlex 2012