Analgesia: Methods of PAIN relief that may be used with or in place of ANALGESICS.Analgesia, Epidural: The relief of pain without loss of consciousness through the introduction of an analgesic agent into the epidural space of the vertebral canal. It is differentiated from ANESTHESIA, EPIDURAL which refers to the state of insensitivity to sensation.Anesthesia, General: Procedure in which patients are induced into an unconscious state through use of various medications so that they do not feel pain during surgery.Analgesia, Obstetrical: The elimination of PAIN, without the loss of CONSCIOUSNESS, during OBSTETRIC LABOR; OBSTETRIC DELIVERY; or the POSTPARTUM PERIOD, usually through the administration of ANALGESICS.Anesthesia: A state characterized by loss of feeling or sensation. This depression of nerve function is usually the result of pharmacologic action and is induced to allow performance of surgery or other painful procedures.Anesthesia, Local: A blocking of nerve conduction to a specific area by an injection of an anesthetic agent.Anesthesia, Epidural: Procedure in which an anesthetic is injected into the epidural space.Anesthesia, Spinal: Procedure in which an anesthetic is injected directly into the spinal cord.Analgesia, Patient-Controlled: Relief of PAIN, without loss of CONSCIOUSNESS, through ANALGESIC AGENTS administered by the patients. It has been used successfully to control POSTOPERATIVE PAIN, during OBSTETRIC LABOR, after BURNS, and in TERMINAL CARE. The choice of agent, dose, and lockout interval greatly influence effectiveness. The potential for overdose can be minimized by combining small bolus doses with a mandatory interval between successive doses (lockout interval).Anesthesia, Conduction: Injection of an anesthetic into the nerves to inhibit nerve transmission in a specific part of the body.Anesthesia, Inhalation: Anesthesia caused by the breathing of anesthetic gases or vapors or by insufflating anesthetic gases or vapors into the respiratory tract.Anesthesia, Intravenous: Process of administering an anesthetic through injection directly into the bloodstream.Anesthesia, Obstetrical: A variety of anesthetic methods such as EPIDURAL ANESTHESIA used to control the pain of childbirth.Analgesics, Opioid: Compounds with activity like OPIATE ALKALOIDS, acting at OPIOID RECEPTORS. Properties include induction of ANALGESIA or NARCOSIS.Pain, Postoperative: Pain during the period after surgery.Anesthetics, Local: Drugs that block nerve conduction when applied locally to nerve tissue in appropriate concentrations. They act on any part of the nervous system and on every type of nerve fiber. In contact with a nerve trunk, these anesthetics can cause both sensory and motor paralysis in the innervated area. Their action is completely reversible. (From Gilman AG, et. al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed) Nearly all local anesthetics act by reducing the tendency of voltage-dependent sodium channels to activate.Bupivacaine: A widely used local anesthetic agent.Anesthesia Recovery Period: The period of emergence from general anesthesia, where different elements of consciousness return at different rates.Fentanyl: A potent narcotic analgesic, abuse of which leads to habituation or addiction. It is primarily a mu-opioid agonist. Fentanyl is also used as an adjunct to general anesthetics, and as an anesthetic for induction and maintenance. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1078)Anesthesia, Dental: A range of methods used to reduce pain and anxiety during dental procedures.Pain Measurement: Scales, questionnaires, tests, and other methods used to assess pain severity and duration in patients or experimental animals to aid in diagnosis, therapy, and physiological studies.Morphine: The principal alkaloid in opium and the prototype opiate analgesic and narcotic. Morphine has widespread effects in the central nervous system and on smooth muscle.Adjuvants, Anesthesia: Agents that are administered in association with anesthetics to increase effectiveness, improve delivery, or decrease required dosage.Nerve Block: Interruption of NEURAL CONDUCTION in peripheral nerves or nerve trunks by the injection of a local anesthetic agent (e.g., LIDOCAINE; PHENOL; BOTULINUM TOXINS) to manage or treat pain.Anesthetics, Intravenous: Ultrashort-acting anesthetics that are used for induction. Loss of consciousness is rapid and induction is pleasant, but there is no muscle relaxation and reflexes frequently are not reduced adequately. Repeated administration results in accumulation and prolongs the recovery time. Since these agents have little if any analgesic activity, they are seldom used alone except in brief minor procedures. (From AMA Drug Evaluations Annual, 1994, p174)Anesthetics, Inhalation: Gases or volatile liquids that vary in the rate at which they induce anesthesia; potency; the degree of circulation, respiratory, or neuromuscular depression they produce; and analgesic effects. Inhalation anesthetics have advantages over intravenous agents in that the depth of anesthesia can be changed rapidly by altering the inhaled concentration. Because of their rapid elimination, any postoperative respiratory depression is of relatively short duration. (From AMA Drug Evaluations Annual, 1994, p173)Anesthetics, Combined: The use of two or more chemicals simultaneously or sequentially to induce anesthesia. The drugs need not be in the same dosage form.Propofol: An intravenous anesthetic agent which has the advantage of a very rapid onset after infusion or bolus injection plus a very short recovery period of a couple of minutes. (From Smith and Reynard, Textbook of Pharmacology, 1992, 1st ed, p206). Propofol has been used as ANTICONVULSANTS and ANTIEMETICS.Acupuncture Analgesia: Analgesia produced by the insertion of ACUPUNCTURE needles at certain ACUPUNCTURE POINTS on the body. This activates small myelinated nerve fibers in the muscle which transmit impulses to the spinal cord and then activate three centers - the spinal cord, midbrain and pituitary/hypothalamus - to produce analgesia.Analgesics: Compounds capable of relieving pain without the loss of CONSCIOUSNESS.Lidocaine: A local anesthetic and cardiac depressant used as an antiarrhythmia agent. Its actions are more intense and its effects more prolonged than those of PROCAINE but its duration of action is shorter than that of BUPIVACAINE or PRILOCAINE.Nitrous Oxide: Nitrogen oxide (N2O). A colorless, odorless gas that is used as an anesthetic and analgesic. High concentrations cause a narcotic effect and may replace oxygen, causing death by asphyxia. It is also used as a food aerosol in the preparation of whipping cream.Sufentanil: An opioid analgesic that is used as an adjunct in anesthesia, in balanced anesthesia, and as a primary anesthetic agent.Methyl Ethers: A group of compounds that contain the general formula R-OCH3.Anesthesiology: A specialty concerned with the study of anesthetics and anesthesia.Isoflurane: A stable, non-explosive inhalation anesthetic, relatively free from significant side effects.Meperidine: A narcotic analgesic that can be used for the relief of most types of moderate to severe pain, including postoperative pain and the pain of labor. Prolonged use may lead to dependence of the morphine type; withdrawal symptoms appear more rapidly than with morphine and are of shorter duration.Pain: An unpleasant sensation induced by noxious stimuli which are detected by NERVE ENDINGS of NOCICEPTIVE NEURONS.Ketamine: A cyclohexanone derivative used for induction of anesthesia. Its mechanism of action is not well understood, but ketamine can block NMDA receptors (RECEPTORS, N-METHYL-D-ASPARTATE) and may interact with sigma receptors.Anesthesia, Caudal: Epidural anesthesia administered via the sacral canal.Anesthetics: Agents that are capable of inducing a total or partial loss of sensation, especially tactile sensation and pain. They may act to induce general ANESTHESIA, in which an unconscious state is achieved, or may act locally to induce numbness or lack of sensation at a targeted site.Monitoring, Intraoperative: The constant checking on the state or condition of a patient during the course of a surgical operation (e.g., checking of vital signs).Labor Pain: Pain associated with OBSTETRIC LABOR in CHILDBIRTH. It is caused primarily by UTERINE CONTRACTION as well as pressure on the CERVIX; BLADDER; and the GASTROINTESTINAL TRACT. Labor pain mostly occurs in the ABDOMEN; the GROIN; and the BACK.Conscious Sedation: A drug-induced depression of consciousness during which patients respond purposefully to verbal commands, either alone or accompanied by light tactile stimulation. No interventions are required to maintain a patent airway. (From: American Society of Anesthesiologists Practice Guidelines)Cesarean Section: Extraction of the FETUS by means of abdominal HYSTEROTOMY.Injections, Spinal: Introduction of therapeutic agents into the spinal region using a needle and syringe.Ambulatory Surgical Procedures: Surgery performed on an outpatient basis. It may be hospital-based or performed in an office or surgicenter.Double-Blind Method: A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.Halothane: A nonflammable, halogenated, hydrocarbon anesthetic that provides relatively rapid induction with little or no excitement. Analgesia may not be adequate. NITROUS OXIDE is often given concomitantly. Because halothane may not produce sufficient muscle relaxation, supplemental neuromuscular blocking agents may be required. (From AMA Drug Evaluations Annual, 1994, p178)Postoperative Nausea and Vomiting: Emesis and queasiness occurring after anesthesia.Preanesthetic Medication: Drugs administered before an anesthetic to decrease a patient's anxiety and control the effects of that anesthetic.Amides: Organic compounds containing the -CO-NH2 radical. Amides are derived from acids by replacement of -OH by -NH2 or from ammonia by the replacement of H by an acyl group. (From Grant & Hackh's Chemical Dictionary, 5th ed)Anesthesia and Analgesia: Medical methods of either relieving pain caused by a particular condition or removing the sensation of pain during a surgery or other medical procedure.Labor, Obstetric: The repetitive uterine contraction during childbirth which is associated with the progressive dilation of the uterine cervix (CERVIX UTERI). Successful labor results in the expulsion of the FETUS and PLACENTA. Obstetric labor can be spontaneous or induced (LABOR, INDUCED).Anesthetics, Dissociative: Intravenous anesthetics that induce a state of sedation, immobility, amnesia, and marked analgesia. Subjects may experience a strong feeling of dissociation from the environment. The condition produced is similar to NEUROLEPTANALGESIA, but is brought about by the administration of a single drug. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed)Tramadol: A narcotic analgesic proposed for severe pain. It may be habituating.Hypnotics and Sedatives: Drugs used to induce drowsiness or sleep or to reduce psychological excitement or anxiety.Alfentanil: A short-acting opioid anesthetic and analgesic derivative of FENTANYL. It produces an early peak analgesic effect and fast recovery of consciousness. Alfentanil is effective as an anesthetic during surgery, for supplementation of analgesia during surgical procedures, and as an analgesic for critically ill patients.Anesthesia, Closed-Circuit: Inhalation anesthesia where the gases exhaled by the patient are rebreathed as some carbon dioxide is simultaneously removed and anesthetic gas and oxygen are added so that no anesthetic escapes into the room. Closed-circuit anesthesia is used especially with explosive anesthetics to prevent fires where electrical sparking from instruments is possible.Mepivacaine: A local anesthetic that is chemically related to BUPIVACAINE but pharmacologically related to LIDOCAINE. It is indicated for infiltration, nerve block, and epidural anesthesia. Mepivacaine is effective topically only in large doses and therefore should not be used by this route. (From AMA Drug Evaluations, 1994, p168)Anesthetics, General: Agents that induce various degrees of analgesia; depression of consciousness, circulation, and respiration; relaxation of skeletal muscle; reduction of reflex activity; and amnesia. There are two types of general anesthetics, inhalation and intravenous. With either type, the arterial concentration of drug required to induce anesthesia varies with the condition of the patient, the desired depth of anesthesia, and the concomitant use of other drugs. (From AMA Drug Evaluations Annual, 1994, p.173)Thiopental: A barbiturate that is administered intravenously for the induction of general anesthesia or for the production of complete anesthesia of short duration.Analgesics, Non-Narcotic: A subclass of analgesic agents that typically do not bind to OPIOID RECEPTORS and are not addictive. Many non-narcotic analgesics are offered as NONPRESCRIPTION DRUGS.Prilocaine: A local anesthetic that is similar pharmacologically to LIDOCAINE. Currently, it is used most often for infiltration anesthesia in dentistry.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.Anesthesia Department, Hospital: Hospital department responsible for the administration of functions and activities pertaining to the delivery of anesthetics.Xylazine: An adrenergic alpha-2 agonist used as a sedative, analgesic and centrally acting muscle relaxant in VETERINARY MEDICINE.Pentobarbital: A short-acting barbiturate that is effective as a sedative and hypnotic (but not as an anti-anxiety) agent and is usually given orally. It is prescribed more frequently for sleep induction than for sedation but, like similar agents, may lose its effectiveness by the second week of continued administration. (From AMA Drug Evaluations Annual, 1994, p236)Naloxone: A specific opiate antagonist that has no agonist activity. It is a competitive antagonist at mu, delta, and kappa opioid receptors.Enflurane: An extremely stable inhalation anesthetic that allows rapid adjustments of anesthesia depth with little change in pulse or respiratory rate.Intubation, Intratracheal: A procedure involving placement of a tube into the trachea through the mouth or nose in order to provide a patient with oxygen and anesthesia.Intraoperative Period: The period during a surgical operation.Pain Threshold: Amount of stimulation required before the sensation of pain is experienced.Intraoperative Complications: Complications that affect patients during surgery. They may or may not be associated with the disease for which the surgery is done, or within the same surgical procedure.Ketorolac: A pyrrolizine carboxylic acid derivative structurally related to INDOMETHACIN. It is an NSAID and is used principally for its analgesic activity. (From Martindale The Extra Pharmacopoeia, 31st ed)Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Piperidines: A family of hexahydropyridines.Clonidine: An imidazoline sympatholytic agent that stimulates ALPHA-2 ADRENERGIC RECEPTORS and central IMIDAZOLINE RECEPTORS. It is commonly used in the management of HYPERTENSION.Femoral Nerve: A nerve originating in the lumbar spinal cord (usually L2 to L4) and traveling through the lumbar plexus to provide motor innervation to extensors of the thigh and sensory innervation to parts of the thigh, lower leg, and foot, and to the hip and knee joints.Interpleural Analgesia: Injection of ANALGESICS; LOCAL ANESTHETICS; or NARCOTICS into the PLEURAL CAVITY between the two pleural membranes.Midazolam: A short-acting hypnotic-sedative drug with anxiolytic and amnestic properties. It is used in dentistry, cardiac surgery, endoscopic procedures, as preanesthetic medication, and as an adjunct to local anesthesia. The short duration and cardiorespiratory stability makes it useful in poor-risk, elderly, and cardiac patients. It is water-soluble at pH less than 4 and lipid-soluble at physiological pH.Drug Tolerance: Progressive diminution of the susceptibility of a human or animal to the effects of a drug, resulting from its continued administration. It should be differentiated from DRUG RESISTANCE wherein an organism, disease, or tissue fails to respond to the intended effectiveness of a chemical or drug. It should also be differentiated from MAXIMUM TOLERATED DOSE and NO-OBSERVED-ADVERSE-EFFECT LEVEL.Anesthesia, IntratrachealBrachial Plexus: The large network of nerve fibers which distributes the innervation of the upper extremity. The brachial plexus extends from the neck into the axilla. In humans, the nerves of the plexus usually originate from the lower cervical and the first thoracic spinal cord segments (C5-C8 and T1), but variations are not uncommon.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Receptors, Opioid, mu: A class of opioid receptors recognized by its pharmacological profile. Mu opioid receptors bind, in decreasing order of affinity, endorphins, dynorphins, met-enkephalin, and leu-enkephalin. They have also been shown to be molecular receptors for morphine.Labor Stage, First: Period from the onset of true OBSTETRIC LABOR to the complete dilatation of the CERVIX UTERI.Dexmedetomidine: A imidazole derivative that is an agonist of ADRENERGIC ALPHA-2 RECEPTORS. It is closely-related to MEDETOMIDINE, which is the racemic form of this compound.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Pirinitramide: A diphenylpropylamine with intense narcotic analgesic activity of long duration. It is a derivative of MEPERIDINE with similar activity and usage.Hydromorphone: An opioid analgesic made from MORPHINE and used mainly as an analgesic. It has a shorter duration of action than morphine.Pain Management: A form of therapy that employs a coordinated and interdisciplinary approach for easing the suffering and improving the quality of life of those experiencing pain.Butorphanol: A synthetic morphinan analgesic with narcotic antagonist action. It is used in the management of severe pain.Postoperative Care: The period of care beginning when the patient is removed from surgery and aimed at meeting the patient's psychological and physical needs directly after surgery. (From Dictionary of Health Services Management, 2d ed)Postoperative Complications: Pathologic processes that affect patients after a surgical procedure. They may or may not be related to the disease for which the surgery was done, and they may or may not be direct results of the surgery.Surgical Procedures, Minor: Surgery restricted to the management of minor problems and injuries; surgical procedures of relatively slight extent and not in itself hazardous to life. (Dorland, 28th ed & Stedman, 25th ed)Hemodynamics: The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.Consciousness: Sense of awareness of self and of the environment.Electroencephalography: Recording of electric currents developed in the brain by means of electrodes applied to the scalp, to the surface of the brain, or placed within the substance of the brain.Surgical Procedures, Operative: Operations carried out for the correction of deformities and defects, repair of injuries, and diagnosis and cure of certain diseases. (Taber, 18th ed.)Nalbuphine: A narcotic used as a pain medication. It appears to be an agonist at kappa opioid receptors and an antagonist or partial agonist at mu opioid receptors.Thoracotomy: Surgical incision into the chest wall.Methohexital: An intravenous anesthetic with a short duration of action that may be used for induction of anesthesia.Receptors, Opioid: Cell membrane proteins that bind opioids and trigger intracellular changes which influence the behavior of cells. The endogenous ligands for opioid receptors in mammals include three families of peptides, the enkephalins, endorphins, and dynorphins. The receptor classes include mu, delta, and kappa receptors. Sigma receptors bind several psychoactive substances, including certain opioids, but their endogenous ligands are not known.Medetomidine: An agonist of RECEPTORS, ADRENERGIC ALPHA-2 that is used in veterinary medicine for its analgesic and sedative properties. It is the racemate of DEXMEDETOMIDINE.Narcotic Antagonists: Agents inhibiting the effect of narcotics on the central nervous system.Perioperative Care: Interventions to provide care prior to, during, and immediately after surgery.Respiration: The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (= OXYGEN CONSUMPTION) or cell respiration (= CELL RESPIRATION).Heart Rate: The number of times the HEART VENTRICLES contract per unit of time, usually per minute.Injections, Intravenous: Injections made into a vein for therapeutic or experimental purposes.Ketoprofen: An IBUPROFEN-type anti-inflammatory analgesic and antipyretic. It is used in the treatment of rheumatoid arthritis and osteoarthritis.Hysterectomy: Excision of the uterus.Postoperative Period: The period following a surgical operation.Intraoperative Care: Patient care procedures performed during the operation that are ancillary to the actual surgery. It includes monitoring, fluid therapy, medication, transfusion, anesthesia, radiography, and laboratory tests.Electroacupuncture: A form of acupuncture with electrical impulses passing through the needles to stimulate NERVE TISSUE. It can be used for ANALGESIA; ANESTHESIA; REHABILITATION; and treatment for diseases.Droperidol: A butyrophenone with general properties similar to those of HALOPERIDOL. It is used in conjunction with an opioid analgesic such as FENTANYL to maintain the patient in a calm state of neuroleptanalgesia with indifference to surroundings but still able to cooperate with the surgeon. It is also used as a premedicant, as an antiemetic, and for the control of agitation in acute psychoses. (From Martindale, The Extra Pharmacopoeia, 29th ed, p593)Hernia, Inguinal: An abdominal hernia with an external bulge in the GROIN region. It can be classified by the location of herniation. Indirect inguinal hernias occur through the internal inguinal ring. Direct inguinal hernias occur through defects in the ABDOMINAL WALL (transversalis fascia) in Hesselbach's triangle. The former type is commonly seen in children and young adults; the latter in adults.Neuromuscular Nondepolarizing Agents: Drugs that interrupt transmission at the skeletal neuromuscular junction without causing depolarization of the motor end plate. They prevent acetylcholine from triggering muscle contraction and are used as muscle relaxants during electroshock treatments, in convulsive states, and as anesthesia adjuvants.Deep Sedation: Drug-induced depression of consciousness during which patients cannot be easily aroused but respond purposely following repeated painful stimulation. The ability to independently maintain ventilatory function may be impaired. (From: American Society of Anesthesiologists Practice Guidelines)Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Abdomen: That portion of the body that lies between the THORAX and the PELVIS.Pruritus: An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief.Infusions, Intravenous: The long-term (minutes to hours) administration of a fluid into the vein through venipuncture, either by letting the fluid flow by gravity or by pumping it.Gynecologic Surgical Procedures: Surgery performed on the female genitalia.Blood Pressure: PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.Epinephrine: The active sympathomimetic hormone from the ADRENAL MEDULLA. It stimulates both the alpha- and beta- adrenergic systems, causes systemic VASOCONSTRICTION and gastrointestinal relaxation, stimulates the HEART, and dilates BRONCHI and cerebral vessels. It is used in ASTHMA and CARDIAC FAILURE and to delay absorption of local ANESTHETICS.Neuromuscular Blocking Agents: Drugs that interrupt transmission of nerve impulses at the skeletal neuromuscular junction. They can be of two types, competitive, stabilizing blockers (NEUROMUSCULAR NONDEPOLARIZING AGENTS) or noncompetitive, depolarizing agents (NEUROMUSCULAR DEPOLARIZING AGENTS). Both prevent acetylcholine from triggering the muscle contraction and they are used as anesthesia adjuvants, as relaxants during electroshock, in convulsive states, etc.Neostigmine: A cholinesterase inhibitor used in the treatment of myasthenia gravis and to reverse the effects of muscle relaxants such as gallamine and tubocurarine. Neostigmine, unlike PHYSOSTIGMINE, does not cross the blood-brain barrier.Patient Satisfaction: The degree to which the individual regards the health care service or product or the manner in which it is delivered by the provider as useful, effective, or beneficial.Xenon: A noble gas with the atomic symbol Xe, atomic number 54, and atomic weight 131.30. It is found in the earth's atmosphere and has been used as an anesthetic.Drug Administration Schedule: Time schedule for administration of a drug in order to achieve optimum effectiveness and convenience.EthersSubarachnoid Space: The space between the arachnoid membrane and PIA MATER, filled with CEREBROSPINAL FLUID. It contains large blood vessels that supply the BRAIN and SPINAL CORD.Opioid Peptides: The endogenous peptides with opiate-like activity. The three major classes currently recognized are the ENKEPHALINS, the DYNORPHINS, and the ENDORPHINS. Each of these families derives from different precursors, proenkephalin, prodynorphin, and PRO-OPIOMELANOCORTIN, respectively. There are also at least three classes of OPIOID RECEPTORS, but the peptide families do not map to the receptors in a simple way.Hyperalgesia: An increased sensation of pain or discomfort produced by mimimally noxious stimuli due to damage to soft tissue containing NOCICEPTORS or injury to a peripheral nerve.Hypotension: Abnormally low BLOOD PRESSURE that can result in inadequate blood flow to the brain and other vital organs. Common symptom is DIZZINESS but greater negative impacts on the body occur when there is prolonged depravation of oxygen and nutrients.Neuromuscular Blockade: The intentional interruption of transmission at the NEUROMUSCULAR JUNCTION by external agents, usually neuromuscular blocking agents. It is distinguished from NERVE BLOCK in which nerve conduction (NEURAL CONDUCTION) is interrupted rather than neuromuscular transmission. Neuromuscular blockade is commonly used to produce MUSCLE RELAXATION as an adjunct to anesthesia during surgery and other medical procedures. It is also often used as an experimental manipulation in basic research. It is not strictly speaking anesthesia but is grouped here with anesthetic techniques. The failure of neuromuscular transmission as a result of pathological processes is not included here.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Carticaine: A thiophene-containing local anesthetic pharmacologically similar to MEPIVACAINE.Ether: A mobile, very volatile, highly flammable liquid used as an inhalation anesthetic and as a solvent for waxes, fats, oils, perfumes, alkaloids, and gums. It is mildly irritating to skin and mucous membranes.Orthopedic Procedures: Procedures used to treat and correct deformities, diseases, and injuries to the MUSCULOSKELETAL SYSTEM, its articulations, and associated structures.Tooth Extraction: The surgical removal of a tooth. (Dorland, 28th ed)Apgar Score: A method, developed by Dr. Virginia Apgar, to evaluate a newborn's adjustment to extrauterine life. Five items - heart rate, respiratory effort, muscle tone, reflex irritability, and color - are evaluated 60 seconds after birth and again five minutes later on a scale from 0-2, 0 being the lowest, 2 being normal. The five numbers are added for the Apgar score. A score of 0-3 represents severe distress, 4-7 indicates moderate distress, and a score of 7-10 predicts an absence of difficulty in adjusting to extrauterine life.Injections, Epidural: The injection of drugs, most often analgesics, into the spinal canal without puncturing the dura mater.Pentazocine: The first mixed agonist-antagonist analgesic to be marketed. It is an agonist at the kappa and sigma opioid receptors and has a weak antagonist action at the mu receptor. (From AMA Drug Evaluations Annual, 1991, p97)Premedication: Preliminary administration of a drug preceding a diagnostic, therapeutic, or surgical procedure. The commonest types of premedication are antibiotics (ANTIBIOTIC PROPHYLAXIS) and anti-anxiety agents. It does not include PREANESTHETIC MEDICATION.Chloralose: A derivative of CHLORAL HYDRATE that was used as a sedative but has been replaced by safer and more effective drugs. Its most common use is as a general anesthetic in animal experiments.Placebo Effect: An effect usually, but not necessarily, beneficial that is attributable to an expectation that the regimen will have an effect, i.e., the effect is due to the power of suggestion.Morphine Derivatives: Analogs or derivatives of morphine.Body Temperature: The measure of the level of heat of a human or animal.Needles: Sharp instruments used for puncturing or suturing.Consciousness Monitors: Devices used to assess the level of consciousness especially during anesthesia. They measure brain activity level based on the EEG.Acetaminophen: Analgesic antipyretic derivative of acetanilide. It has weak anti-inflammatory properties and is used as a common analgesic, but may cause liver, blood cell, and kidney damage.Laryngeal Masks: A type of oropharyngeal airway that provides an alternative to endotracheal intubation and standard mask anesthesia in certain patients. It is introduced into the hypopharynx to form a seal around the larynx thus permitting spontaneous or positive pressure ventilation without penetration of the larynx or esophagus. It is used in place of a facemask in routine anesthesia. The advantages over standard mask anesthesia are better airway control, minimal anesthetic gas leakage, a secure airway during patient transport to the recovery area, and minimal postoperative problems.Delivery, Obstetric: Delivery of the FETUS and PLACENTA under the care of an obstetrician or a health worker. Obstetric deliveries may involve physical, psychological, medical, or surgical interventions.Spinal Cord: A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.Carbon Dioxide: A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.Periaqueductal Gray: Central gray matter surrounding the CEREBRAL AQUEDUCT in the MESENCEPHALON. Physiologically it is probably involved in RAGE reactions, the LORDOSIS REFLEX; FEEDING responses, bladder tonus, and pain.Ephedrine: A phenethylamine found in EPHEDRA SINICA. PSEUDOEPHEDRINE is an isomer. It is an alpha- and beta-adrenergic agonist that may also enhance release of norepinephrine. It has been used for asthma, heart failure, rhinitis, and urinary incontinence, and for its central nervous system stimulatory effects in the treatment of narcolepsy and depression. It has become less extensively used with the advent of more selective agonists.Pain Perception: The process by which PAIN is recognized and interpreted by the brain.Injections: Introduction of substances into the body using a needle and syringe.Oxycodone: A semisynthetic derivative of CODEINE.Drug Interactions: The action of a drug that may affect the activity, metabolism, or toxicity of another drug.Infusion Pumps: Fluid propulsion systems driven mechanically, electrically, or osmotically that are used to inject (or infuse) over time agents into a patient or experimental animal; used routinely in hospitals to maintain a patent intravenous line, to administer antineoplastic agents and other drugs in thromboembolism, heart disease, diabetes mellitus (INSULIN INFUSION SYSTEMS is also available), and other disorders.Single-Blind Method: A method in which either the observer(s) or the subject(s) is kept ignorant of the group to which the subjects are assigned.Adrenergic alpha-Agonists: Drugs that selectively bind to and activate alpha adrenergic receptors.Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Obstetric Labor Complications: Medical problems associated with OBSTETRIC LABOR, such as BREECH PRESENTATION; PREMATURE OBSTETRIC LABOR; HEMORRHAGE; or others. These complications can affect the well-being of the mother, the FETUS, or both.Narcotics: Agents that induce NARCOSIS. Narcotics include agents that cause somnolence or induced sleep (STUPOR); natural or synthetic derivatives of OPIUM or MORPHINE or any substance that has such effects. They are potent inducers of ANALGESIA and OPIOID-RELATED DISORDERS.Intraoperative Awareness: Occurence of a patient becoming conscious during a procedure performed under GENERAL ANESTHESIA and subsequently having recall of these events. (From Anesthesiology 2006, 104(4): 847-64.)Etomidate: Imidazole derivative anesthetic and hypnotic with little effect on blood gases, ventilation, or the cardiovascular system. It has been proposed as an induction anesthetic.Nociceptors: Peripheral AFFERENT NEURONS which are sensitive to injuries or pain, usually caused by extreme thermal exposures, mechanical forces, or other noxious stimuli. Their cell bodies reside in the DORSAL ROOT GANGLIA. Their peripheral terminals (NERVE ENDINGS) innervate target tissues and transduce noxious stimuli via axons to the CENTRAL NERVOUS SYSTEM.Anti-Inflammatory Agents, Non-Steroidal: Anti-inflammatory agents that are non-steroidal in nature. In addition to anti-inflammatory actions, they have analgesic, antipyretic, and platelet-inhibitory actions.They act by blocking the synthesis of prostaglandins by inhibiting cyclooxygenase, which converts arachidonic acid to cyclic endoperoxides, precursors of prostaglandins. Inhibition of prostaglandin synthesis accounts for their analgesic, antipyretic, and platelet-inhibitory actions; other mechanisms may contribute to their anti-inflammatory effects.Succinylcholine: A quaternary skeletal muscle relaxant usually used in the form of its bromide, chloride, or iodide. It is a depolarizing relaxant, acting in about 30 seconds and with a duration of effect averaging three to five minutes. Succinylcholine is used in surgical, anesthetic, and other procedures in which a brief period of muscle relaxation is called for.Cervical Plexus: A network of nerve fibers originating in the upper four CERVICAL SPINAL CORD segments. The cervical plexus distributes cutaneous nerves to parts of the neck, shoulders, and back of the head. It also distributes motor fibers to muscles of the cervical SPINAL COLUMN, infrahyoid muscles, and the DIAPHRAGM.Shivering: Involuntary contraction or twitching of the muscles. It is a physiologic method of heat production in man and other mammals.Nurse Anesthetists: Professional nurses who have completed postgraduate training in the administration of anesthetics and who function under the responsibility of the operating surgeon.Manuals as Topic: Books designed to give factual information or instructions.Blood Gas Analysis: Measurement of oxygen and carbon dioxide in the blood.Laryngoscopy: Examination, therapy or surgery of the interior of the larynx performed with a specially designed endoscope.Antiemetics: Drugs used to prevent NAUSEA or VOMITING.Tetracaine: A potent local anesthetic of the ester type used for surface and spinal anesthesia.Mandibular Nerve: A branch of the trigeminal (5th cranial) nerve. The mandibular nerve carries motor fibers to the muscles of mastication and sensory fibers to the teeth and gingivae, the face in the region of the mandible, and parts of the dura.Procaine: A local anesthetic of the ester type that has a slow onset and a short duration of action. It is mainly used for infiltration anesthesia, peripheral nerve block, and spinal block. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1016).Pain, Intractable: Persistent pain that is refractory to some or all forms of treatment.Androstanols: Androstanes and androstane derivatives which are substituted in any position with one or more hydroxyl groups.Preoperative Care: Care given during the period prior to undergoing surgery when psychological and physical preparations are made according to the special needs of the individual patient. This period spans the time between admission to the hospital to the time the surgery begins. (From Dictionary of Health Services Management, 2d ed)Autonomic Nerve Block: Interruption of sympathetic pathways, by local injection of an anesthetic agent, at any of four levels: peripheral nerve block, sympathetic ganglion block, extradural block, and subarachnoid block.Hypotension, Controlled: Procedure in which arterial blood pressure is intentionally reduced in order to control blood loss during surgery. This procedure is performed either pharmacologically or by pre-surgical removal of blood.Extraction, Obstetrical: Extraction of the fetus by means of obstetrical instruments.Drug Combinations: Single preparations containing two or more active agents, for the purpose of their concurrent administration as a fixed dose mixture.Tourniquets: Devices for the compression of a blood vessel by application around an extremity to control the circulation and prevent the flow of blood to or from the distal area. (From Dorland, 28th ed)Codeine: An opioid analgesic related to MORPHINE but with less potent analgesic properties and mild sedative effects. It also acts centrally to suppress cough.Hypnosis, Anesthetic: Procedure in which an individual is induced into a trance-like state to relieve pain. This procedure is frequently performed with local but not general ANESTHESIA.Operating Rooms: Facilities equipped for performing surgery.Opium: The air-dried exudate from the unripe seed capsule of the opium poppy, Papaver somniferum, or its variant, P. album. It contains a number of alkaloids, but only a few - MORPHINE; CODEINE; and PAPAVERINE - have clinical significance. Opium has been used as an analgesic, antitussive, antidiarrheal, and antispasmodic.Injections, Intramuscular: Forceful administration into a muscle of liquid medication, nutrient, or other fluid through a hollow needle piercing the muscle and any tissue covering it.Administration, Rectal: The insertion of drugs into the rectum, usually for confused or incompetent patients, like children, infants, and the very old or comatose.Random Allocation: A process involving chance used in therapeutic trials or other research endeavor for allocating experimental subjects, human or animal, between treatment and control groups, or among treatment groups. It may also apply to experiments on inanimate objects.Ophthalmologic Surgical Procedures: Surgery performed on the eye or any of its parts.Sensation: The process in which specialized SENSORY RECEPTOR CELLS transduce peripheral stimuli (physical or chemical) into NERVE IMPULSES which are then transmitted to the various sensory centers in the CENTRAL NERVOUS SYSTEM.