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.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.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).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.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.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.Bupivacaine: A widely used local anesthetic agent.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.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.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)Analgesics: Compounds capable of relieving pain without the loss of CONSCIOUSNESS.Anesthesia, Epidural: Procedure in which an anesthetic is injected into the epidural space.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.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.Sufentanil: An opioid analgesic that is used as an adjunct in anesthesia, in balanced anesthesia, and as a primary anesthetic agent.Pain: An unpleasant sensation induced by noxious stimuli which are detected by NERVE ENDINGS of NOCICEPTIVE NEURONS.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.Injections, Spinal: Introduction of therapeutic agents into the spinal region using a needle and syringe.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).Anesthesia, Obstetrical: A variety of anesthetic methods such as EPIDURAL ANESTHESIA used to control the pain of childbirth.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, Spinal: Procedure in which an anesthetic is injected directly into the spinal cord.Tramadol: A narcotic analgesic proposed for severe pain. It may be habituating.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.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.Naloxone: A specific opiate antagonist that has no agonist activity. It is a competitive antagonist at mu, delta, and kappa opioid receptors.Cesarean Section: Extraction of the FETUS by means of abdominal HYSTEROTOMY.Postoperative Nausea and Vomiting: Emesis and queasiness occurring after anesthesia.Pain Threshold: Amount of stimulation required before the sensation of pain is experienced.Interpleural Analgesia: Injection of ANALGESICS; LOCAL ANESTHETICS; or NARCOTICS into the PLEURAL CAVITY between the two pleural membranes.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.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.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.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)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)Labor Stage, First: Period from the onset of true OBSTETRIC LABOR to the complete dilatation of the CERVIX UTERI.Hydromorphone: An opioid analgesic made from MORPHINE and used mainly as an analgesic. It has a shorter duration of action than morphine.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.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.Anesthesia, Caudal: Epidural anesthesia administered via the sacral canal.Clonidine: An imidazoline sympatholytic agent that stimulates ALPHA-2 ADRENERGIC RECEPTORS and central IMIDAZOLINE RECEPTORS. It is commonly used in the management of HYPERTENSION.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.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.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.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.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Pirinitramide: A diphenylpropylamine with intense narcotic analgesic activity of long duration. It is a derivative of MEPERIDINE with similar activity and usage.Hypnotics and Sedatives: Drugs used to induce drowsiness or sleep or to reduce psychological excitement or anxiety.Butorphanol: A synthetic morphinan analgesic with narcotic antagonist action. It is used in the management of severe pain.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.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.Narcotic Antagonists: Agents inhibiting the effect of narcotics on the central nervous system.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.Anesthesia, Conduction: Injection of an anesthetic into the nerves to inhibit nerve transmission in a specific part of the body.Thoracotomy: Surgical incision into the chest wall.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.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.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)Pruritus: An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief.Ketoprofen: An IBUPROFEN-type anti-inflammatory analgesic and antipyretic. It is used in the treatment of rheumatoid arthritis and osteoarthritis.Adjuvants, Anesthesia: Agents that are administered in association with anesthetics to increase effectiveness, improve delivery, or decrease required dosage.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.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.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, Local: A blocking of nerve conduction to a specific area by an injection of an anesthetic agent.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.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.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)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)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.Ambulatory Surgical Procedures: Surgery performed on an outpatient basis. It may be hospital-based or performed in an office or surgicenter.Hysterectomy: Excision of the uterus.Piperidines: A family of hexahydropyridines.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Brachial 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.Pain, Intractable: Persistent pain that is refractory to some or all forms of treatment.Oxycodone: A semisynthetic derivative of CODEINE.Pain Perception: The process by which PAIN is recognized and interpreted by the brain.Injections, Epidural: The injection of drugs, most often analgesics, into the spinal canal without puncturing the dura mater.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.Anesthesia, Intravenous: Process of administering an anesthetic through injection directly into the bloodstream.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)Prilocaine: A local anesthetic that is similar pharmacologically to LIDOCAINE. Currently, it is used most often for infiltration anesthesia in dentistry.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.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.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.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.Nociceptive Pain: Dull or sharp aching pain caused by stimulated NOCICEPTORS due to tissue injury, inflammation or diseases. It can be divided into somatic or tissue pain and VISCERAL PAIN.Injections, Intravenous: Injections made into a vein for therapeutic or experimental purposes.Extraction, Obstetrical: Extraction of the fetus by means of obstetrical instruments.Dipyrone: A drug that has analgesic, anti-inflammatory, and antipyretic properties. It is the sodium sulfonate of AMINOPYRINE.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.Spinal Cord: A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.Drug Administration Schedule: Time schedule for administration of a drug in order to achieve optimum effectiveness and convenience.Subarachnoid 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.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.Injections, Intra-Articular: Methods of delivering drugs into a joint space.Codeine: An opioid analgesic related to MORPHINE but with less potent analgesic properties and mild sedative effects. It also acts centrally to suppress cough.Nefopam: Non-narcotic analgesic chemically similar to ORPHENADRINE. Its mechanism of action is unclear. It is used for the relief of acute and chronic pain. (From Martindale, The Extra Pharmacopoeia, 30th ed, p26)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.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.Buprenorphine: A derivative of the opioid alkaloid THEBAINE that is a more potent and longer lasting analgesic than MORPHINE. It appears to act as a partial agonist at mu and kappa opioid receptors and as an antagonist at delta receptors. The lack of delta-agonist activity has been suggested to account for the observation that buprenorphine tolerance may not develop with chronic use.Perioperative Care: Interventions to provide care prior to, during, and immediately after surgery.Heroin: A narcotic analgesic that may be habit-forming. It is a controlled substance (opium derivative) listed in the U.S. Code of Federal Regulations, Title 21 Parts 329.1, 1308.11 (1987). Sale is forbidden in the United States by Federal statute. (Merck Index, 11th 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.Preanesthetic Medication: Drugs administered before an anesthetic to decrease a patient's anxiety and control the effects of that anesthetic.Administration, Rectal: The insertion of drugs into the rectum, usually for confused or incompetent patients, like children, infants, and the very old or comatose.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.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.Anesthesia Recovery Period: The period of emergence from general anesthesia, where different elements of consciousness return at different rates.Receptors, Opioid, kappa: A class of opioid receptors recognized by its pharmacological profile. Kappa opioid receptors bind dynorphins with a higher affinity than endorphins which are themselves preferred to enkephalins.Receptors, Opioid, delta: A class of opioid receptors recognized by its pharmacological profile. Delta opioid receptors bind endorphins and enkephalins with approximately equal affinity and have less affinity for dynorphins.ThiazinesInfusion 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.beta-Endorphin: A 31-amino acid peptide that is the C-terminal fragment of BETA-LIPOTROPIN. It acts on OPIOID RECEPTORS and is an analgesic. Its first four amino acids at the N-terminal are identical to the tetrapeptide sequence of METHIONINE ENKEPHALIN and LEUCINE ENKEPHALIN.Enkephalin, Ala(2)-MePhe(4)-Gly(5)-: An enkephalin analog that selectively binds to the MU OPIOID RECEPTOR. It is used as a model for drug permeability experiments.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.Time Factors: Elements of limited time intervals, contributing to particular results or situations.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.Dihydromorphine: A semisynthetic analgesic used in the study of narcotic receptors.Adrenergic alpha-Agonists: Drugs that selectively bind to and activate alpha adrenergic receptors.Nociception: Sensing of noxious mechanical, thermal or chemical stimuli by NOCICEPTORS. It is the sensory component of visceral and tissue pain (NOCICEPTIVE PAIN).Naltrexone: Derivative of noroxymorphone that is the N-cyclopropylmethyl congener of NALOXONE. It is a narcotic antagonist that is effective orally, longer lasting and more potent than naloxone, and has been proposed for the treatment of heroin addiction. The FDA has approved naltrexone for the treatment of alcohol dependence.Drug Combinations: Single preparations containing two or more active agents, for the purpose of their concurrent administration as a fixed dose mixture.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.Enkephalins: One of the three major families of endogenous opioid peptides. The enkephalins are pentapeptides that are widespread in the central and peripheral nervous systems and in the adrenal medulla.Infusions, Parenteral: The administration of liquid medication, nutrient, or other fluid through some other route than the alimentary canal, usually over minutes or hours, either by gravity flow or often by infusion pumping.Endorphins: One of the three major groups of endogenous opioid peptides. They are large peptides derived from the PRO-OPIOMELANOCORTIN precursor. The known members of this group are alpha-, beta-, and gamma-endorphin. The term endorphin is also sometimes used to refer to all opioid peptides, but the narrower sense is used here; OPIOID PEPTIDES is used for the broader group.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.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)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.Morphinans: Compounds based on a partially saturated iminoethanophenanthrene, which can be described as ethylimino-bridged benzo-decahydronaphthalenes. They include some of the OPIOIDS found in PAPAVER that are used as ANALGESICS.Gynecologic Surgical Procedures: Surgery performed on the female genitalia.Behavior, Animal: The observable response an animal makes to any situation.Anesthesia, Dental: A range of methods used to reduce pain and anxiety during dental procedures.Neuralgia: Intense or aching pain that occurs along the course or distribution of a peripheral or cranial nerve.Doulas: Trained lay women who provide emotional and/or physical support during obstetric labor and the postpartum period for mothers and their partners.Labor Stage, Second: The period of OBSTETRIC LABOR that is from the complete dilatation of the CERVIX UTERI to the expulsion of the FETUS.Tolmetin: A non-steroidal anti-inflammatory agent (ANTI-INFLAMMATORY AGENTS, NON-STEROIDAL) similar in mode of action to INDOMETHACIN.Piroxicam: A cyclooxygenase inhibiting, non-steroidal anti-inflammatory agent (NSAID) that is well established in treating rheumatoid arthritis and osteoarthritis and used for musculoskeletal disorders, dysmenorrhea, and postoperative pain. Its long half-life enables it to be administered once daily.Acupuncture Points: Designated locations along nerves or organ meridians for inserting acupuncture needles.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).Orthopedic Procedures: Procedures used to treat and correct deformities, diseases, and injuries to the MUSCULOSKELETAL SYSTEM, its articulations, and associated structures.Acute Pain: Intensely discomforting, distressful, or agonizing sensation associated with trauma or disease, with well-defined location, character, and timing.Injections, Intraventricular: Injections into the cerebral ventricles.Oxymorphone: An opioid analgesic with actions and uses similar to those of MORPHINE, apart from an absence of cough suppressant activity. It is used in the treatment of moderate to severe pain, including pain in obstetrics. It may also be used as an adjunct to anesthesia. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1092)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.Epidural Space: Space between the dura mater and the walls of the vertebral canal.Postoperative Period: The period following a surgical operation.Arthroplasty, Replacement, Knee: Replacement of the knee joint.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)Diclofenac: A non-steroidal anti-inflammatory agent (NSAID) with antipyretic and analgesic actions. It is primarily available as the sodium salt.Heart Rate, Fetal: The heart rate of the FETUS. The normal range at term is between 120 and 160 beats per minute.Drug Interactions: The action of a drug that may affect the activity, metabolism, or toxicity of another drug.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.Adrenergic alpha-2 Receptor Agonists: Compounds that bind to and activate ADRENERGIC ALPHA-2 RECEPTORS.Nausea: An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses.Arthroscopy: Endoscopic examination, therapy and surgery of the joint.Cyclohexanecarboxylic AcidsSingle-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.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.Transcutaneous Electric Nerve Stimulation: The use of specifically placed small electrodes to deliver electrical impulses across the SKIN to relieve PAIN. It is used less frequently to produce ANESTHESIA.Injections, Subcutaneous: Forceful administration under the skin of liquid medication, nutrient, or other fluid through a hollow needle piercing the skin.Vomiting: The forcible expulsion of the contents of the STOMACH through the MOUTH.Antiemetics: Drugs used to prevent NAUSEA or VOMITING.Drug Therapy, Combination: Therapy with two or more separate preparations given for a combined effect.Morphine Dependence: Strong dependence, both physiological and emotional, upon morphine.Parity: The number of offspring a female has borne. It is contrasted with GRAVIDITY, which refers to the number of pregnancies, regardless of outcome.Catheterization: Use or insertion of a tubular device into a duct, blood vessel, hollow organ, or body cavity for injecting or withdrawing fluids for diagnostic or therapeutic purposes. It differs from INTUBATION in that the tube here is used to restore or maintain patency in obstructions.Sciatic Nerve: A nerve which originates in the lumbar and sacral spinal cord (L4 to S3) and supplies motor and sensory innervation to the lower extremity. The sciatic nerve, which is the main continuation of the sacral plexus, is the largest nerve in the body. It has two major branches, the TIBIAL NERVE and the PERONEAL NERVE.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.Tooth Extraction: The surgical removal of a tooth. (Dorland, 28th ed)Enkephalin, D-Penicillamine (2,5)-: A disulfide opioid pentapeptide that selectively binds to the DELTA OPIOID RECEPTOR. It possesses antinociceptive activity.Ketorolac Tromethamine: A pyrrolizine carboxylic acid derivative structurally related to INDOMETHACIN. It is a non-steroidal anti-inflammatory agent used for analgesia for postoperative pain and inhibits cyclooxygenase activity.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Tonsillectomy: Surgical removal of a tonsil or tonsils. (Dorland, 28th ed)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.Intraoperative Period: The period during a surgical operation.Enkephalin, Leucine: One of the endogenous pentapeptides with morphine-like activity. It differs from MET-ENKEPHALIN in the LEUCINE at position 5. Its first four amino acid sequence is identical to the tetrapeptide sequence at the N-terminal of BETA-ENDORPHIN.Receptors, Adrenergic, alpha-2: A subclass of alpha-adrenergic receptors found on both presynaptic and postsynaptic membranes where they signal through Gi-Go G-PROTEINS. While postsynaptic alpha-2 receptors play a traditional role in mediating the effects of ADRENERGIC AGONISTS, the subset of alpha-2 receptors found on presynaptic membranes signal the feedback inhibition of NEUROTRANSMITTER release.Drug Synergism: The action of a drug in promoting or enhancing the effectiveness of another drug.Catheterization, Peripheral: Insertion of a catheter into a peripheral artery, vein, or airway for diagnostic or therapeutic purposes.Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.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.Reaction Time: The time from the onset of a stimulus until a response is observed.