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Anaesthesia
Anesthesia is a state of controlled, temporary loss of sensation or awareness that is induced for medical or veterinary purposes. It may include some or all of analgesia (relief from or prevention of pain), paralysis (muscle relaxation), amnesia (loss of memory), and unconsciousness. An individual under the effects of anesthetic drugs is referred to as being anesthetized. Anesthesia enables the painless performance of procedures that would otherwise cause severe or intolerable pain in a non-anesthetized individual, or would otherwise be technically unfeasible. Three broad categories of anesthesia exist: * General anesthesia suppresses central nervous system activity and results in unconsciousness and total lack of sensation, using either injected or inhaled drugs. * Sedation suppresses the central nervous system to a lesser degree, inhibiting both anxiety and creation of long-term memories without resulting in unconsciousness. * Regional and local anesthesia, which blocks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Anaesthesia
General anaesthesia (UK) or general anesthesia (US) is a medically induced loss of consciousness that renders the patient unarousable even with painful stimuli. This effect is achieved by administering either intravenous or inhalational general anaesthetic medications, which often act in combination with an analgesic and neuromuscular blocking agent. Spontaneous ventilation is often inadequate during the procedure and intervention is often necessary to protect the airway. General anaesthesia is generally performed in an operating theater to allow surgical procedures that would otherwise be intolerably painful for a patient, or in an intensive care unit or emergency department to facilitate endotracheal intubation and mechanical ventilation in critically ill patients. A variety of drugs may be administered, with the overall goal of achieving unconsciousness, amnesia, analgesia, loss of reflexes of the autonomic nervous system, and in some cases paralysis of skeletal musc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinal Anaesthesia
Spinal anaesthesia (or spinal anesthesia), also called spinal block, subarachnoid block, intradural block and intrathecal block, is a form of neuraxial regional anaesthesia involving the injection of a local anaesthetic or opioid into the subarachnoid space, generally through a fine needle, usually long. It is a safe and effective form of anesthesia usually performed by anesthesiologists that can be used as an alternative to general anesthesia commonly in surgeries involving the lower extremities and surgeries below the umbilicus. The local anesthetic with or without an opioid injected into the cerebrospinal fluid provides locoregional anaesthesia: true analgesia, motor, sensory and autonomic (sympathic) blockade. Administering analgesics (opioid, alpha2-adrenoreceptor agonist) in the cerebrospinal fluid without a local anaesthetic produces locoregional analgesia: markedly reduced pain sensation (incomplete analgesia), some autonomic blockade (parasympathetic plexi), but no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Local Anesthetic
A local anesthetic (LA) is a medication that causes absence of pain sensation. In the context of surgery, a local anesthetic creates an absence of pain in a specific location of the body without a loss of consciousness, as opposed to a general anesthetic. When it is used on specific nerve pathways ( local anesthetic nerve block), paralysis (loss of muscle power) also can be achieved. Examples Short Duration & Low Potency Procaine Chloroprocaine Medium Duration & Potency Lidocaine Prilocaine High Duration & Potency Tetracaine Bupivacaine Cinchocaine Ropivacaine Clinical LAs belong to one of two classes: aminoamide and aminoester local anesthetics. Synthetic LAs are structurally related to cocaine. They differ from cocaine mainly in that they have a very low abuse potential and do not produce hypertension or (with few exceptions) vasoconstriction. They are used in various techniques of local anesthesia such as: * Topical anesthesia (surface) * Topical ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Anaesthetic
General anaesthetics (or anesthetics, see spelling differences) are often defined as compounds that induce a loss of consciousness in humans or loss of righting reflex in animals. Clinical definitions are also extended to include an induced coma that causes lack of awareness to painful stimuli, sufficient to facilitate surgical applications in clinical and veterinary practice. General anaesthetics do not act as analgesics and should also not be confused with sedatives. General anaesthetics are a structurally diverse group of compounds whose mechanisms encompasses multiple biological targets involved in the control of neuronal pathways. The precise workings are the subject of some debate and ongoing research. General anesthetics elicit a state of general anesthesia. It remains somewhat controversial regarding how this state should be defined. General anesthetics, however, typically elicit several key reversible effects: immobility, analgesia, amnesia, unconsciousness, and re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epidural Anaesthesia
Epidural administration (from Ancient Greek ἐπί, , upon" + ''dura mater'') is a method of medication administration in which a medicine is injected into the epidural space around the spinal cord. The epidural route is used by physicians and nurse anesthetists to administer local anesthetic agents, analgesics, diagnostic medicines such as radiocontrast agents, and other medicines such as glucocorticoids. Epidural administration involves the placement of a catheter into the epidural space, which may remain in place for the duration of the treatment. The technique of intentional epidural administration of medication was first described in 1921 by Spanish military surgeon Fidel Pagés. In the United States, over 50% of childbirths involve the use of epidural anesthesia. Epidural anaesthesia causes a loss of sensation, including pain, by blocking the transmission of signals through nerve fibres in or near the spinal cord. For this reason, epidurals are commonly used for pai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analgesic
An analgesic drug, also called simply an analgesic (American English), analgaesic (British English), pain reliever, or painkiller, is any member of the group of drugs used to achieve relief from pain (that is, analgesia or pain management). It is typically used to induce cooperation with a medical procedure. Analgesics are conceptually distinct from anesthetics, which temporarily reduce, and in some instances eliminate, sensation, although analgesia and anesthesia are neurophysiologically overlapping and thus various drugs have both analgesic and anesthetic effects. Analgesic choice is also determined by the type of pain: For neuropathic pain, traditional analgesics are less effective, and there is often benefit from classes of drugs that are not normally considered analgesics, such as tricyclic antidepressants and anticonvulsants. Various analgesics, such as many NSAIDs, are available over the counter in most countries, whereas various others are prescription drugs owi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malignant Hyperthermia
Malignant hyperthermia (MH) is a type of severe reaction that occurs in response to particular medications used during general anesthesia, among those who are susceptible. Symptoms include muscle rigidity, fever, and a fast heart rate. Complications can include muscle breakdown and high blood potassium. Most people who are susceptible to MH are generally unaffected when not exposed to triggering agents. Exposure to triggering agents (certain volatile anesthetic agents or succinylcholine) can lead to the development of MH in those who are susceptible. Susceptibility can occur due to at least six genetic mutations, with the most common one being of the RYR1 gene. These genetic variations are often inherited from a person's parents in an autosomal dominant manner. The condition may also occur as a new mutation or be associated with a number of inherited muscle diseases, such as central core disease. In susceptible individuals, the medications induce the release of stored c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Local Anesthesia
Local anesthesia is any technique to induce the absence of sensation in a specific part of the body, generally for the aim of inducing local analgesia, that is, local insensitivity to pain, although other local senses may be affected as well. It allows patients to undergo surgical and dental procedures with reduced pain and distress. In many situations, such as cesarean section, it is safer and therefore superior to general anesthesia. The following terms are often used interchangeably: * ''Local anesthesia'', in a strict sense, is anesthesia of a small part of the body such as a tooth or an area of skin. * ''Regional anesthesia'' is aimed at anesthetizing a larger part of the body such as a leg or arm. * ''Conduction anesthesia'' encompasses a great variety of local and regional anesthetic techniques. Medical A local anesthetic is a drug that causes reversible local anesthesia and a loss of nociception. When it is used on specific nerve pathways ( nerve block), effects suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nerve Block
Nerve block or regional nerve blockade is any deliberate interruption of signals traveling along a nerve, often for the purpose of pain relief. Local anesthetic nerve block (sometimes referred to as simply "nerve block") is a short-term block, usually lasting hours or days, involving the injection of an anesthetic, a corticosteroid, and other agents onto or near a nerve. Neurolytic block, the deliberate temporary degeneration of nerve fibers through the application of chemicals, heat, or freezing, produces a block that may persist for weeks, months, or indefinitely. Neurectomy, the cutting through or removal of a nerve or a section of a nerve, usually produces a permanent block. Because neurectomy of a sensory nerve is often followed, months later, by the emergence of new, more intense pain, sensory nerve neurectomy is rarely performed. The concept of nerve block sometimes includes ''central nerve block'', which includes epidural and spinal anaesthesia. Local anesthetic ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dissociative
Dissociatives, colloquially dissos, are a subclass of hallucinogens which distort perception of sight and sound and produce feelings of detachment – dissociation – from the environment and/or self. Although many kinds of drugs are capable of such action, dissociatives are unique in that they do so in such a way that they produce hallucinogenic effects, which may include dissociation, a general decrease in sensory experience, hallucinations, dream-like states or anesthesia. Some of these substances, which are nonselective in action and affect the dopamine and/or opioid systems, may be capable of inducing euphoria or symptoms which are more akin to the effects of certain “ hard drugs” or common drugs of abuse. This is likely why dissociatives are considered to be addictive with a fair to moderate potential for abuse, unlike psychedelics. Despite some dissociatives, such as phencyclidine (PCP) possessing stimulating properties, most dissociatives seem to have a general d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuromuscular-blocking Drug
Neuromuscular-blocking drugs block neuromuscular transmission at the neuromuscular junction, causing paralysis of the affected skeletal muscles. This is accomplished via their action on the post-synaptic acetylcholine (Nm) receptors. In clinical use, neuromuscular block is used adjunctively to anesthesia to produce paralysis, firstly to paralyze the vocal cords, and permit intubation of the trachea, and secondly to optimize the surgical field by inhibiting spontaneous ventilation, and causing relaxation of skeletal muscles. Because the appropriate dose of neuromuscular-blocking drug may paralyze muscles required for breathing (i.e., the diaphragm), mechanical ventilation should be available to maintain adequate respiration. Patients are still aware of pain even after full conduction block has occurred; hence, general anesthetics and/or analgesics must also be given to prevent anesthesia awareness. Nomenclature Neuromuscular blocking drugs are often classified into two br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedation
Sedation is the reduction of irritability or agitation by administration of sedative drugs, generally to facilitate a medical procedure or diagnostic procedure. Examples of drugs which can be used for sedation include isoflurane, diethyl ether, propofol, etomidate, ketamine, pentobarbital, lorazepam and midazolam. Medical uses Sedation is typically used in minor surgical procedures such as endoscopy, vasectomy, or dentistry and for reconstructive surgery, some cosmetic surgeries, removal of wisdom teeth, or for high-anxiety patients. Sedation methods in dentistry include inhalation sedation (using nitrous oxide), oral sedation, and intravenous (IV) sedation. Inhalation sedation is also sometimes referred to as ''relative analgesia''. Sedation is also used extensively in the intensive care unit so that patients who are being ventilated tolerate having an endotracheal tube in their trachea. It can also be used during a long term brain EEG to help patient relax. Risks The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
