segmental anesthesia


anesthesia

 [an″es-the´ze-ah] 1. lack of feeling or sensation.2. artificially induced loss of ability to feel pain, done to permit the performance of surgery or other painful procedures. It may be produced by a number of agents (anesthetics) capable of bringing about partial or complete loss of sensation.(See accompanying table.)Patient Care. Interventions of the health care team will be individualized based on the type of procedure the patient has undergone and the type of anesthesia administered. Patients recovering from general anesthesia must be assessed constantly until they have reacted. The vital signs and blood pressure are checked regularly; any sudden change is reported immediately. They must be observed to see that the airway is clear at all times. The observation is in specialized recovery rooms called postanesthesia care units that are equipped with a variety of monitors to measure such variables as blood pressure, respiratory and pulse rates, cardiac output, body temperature, fluid balance, and oxygenation. When necessary, patients are initially managed with ventilators that inflate the lungs mechanically through endotracheal tubes. Changes in breathing pattern, eye movements, lacrimation, and muscle tone are indicators for the depth of anesthesia. Breathing patterns are the most sensitive of these.
When patients are awakening from general anesthesia they may be restless, attempting to get out of bed or even striking out at those around them because they are afraid and disoriented. This state is called emergence delirium and should be assessed, as it can indicate hypoxia. Retrograde amnesia may be associated with the administration of anesthesia and adjuncts, causing the patient to forget events occurring in the immediate postoperative period.
ambulatory anesthesia anesthesia performed on an outpatient basis for ambulatory surgery.balanced anesthesia anesthesia that uses a combination of drugs, each in an amount sufficient to produce its major or desired effect to the optimum degree and to keep undesirable effects to a minimum.basal anesthesia a reversible state of central nervous system depression produced by preliminary medication so that the inhalation of anesthetic necessary to produce surgical anesthesia is greatly reduced.block anesthesia regional anesthesia.caudal anesthesia a type of regional anesthesia that was used in childbirth between the 1940s and the 1960s. The anesthetizing solution, usually procaine, was injected into the caudal area of the spinal canal through the lower end of the sacrum and affected the caudal nerve roots, rendering the cervix, vagina, and perineum insensitive to pain. Called also caudal block.central anesthesia lack of sensation caused by disease of the nerve centers.closed circuit anesthesia that produced by continuous rebreathing of a small amount of anesthetic gas in a closed system with an apparatus for removing carbon dioxide.compression anesthesia loss of sensation resulting from pressure on a nerve.crossed anesthesia loss of sensation on one side of the face and loss of pain and temperature sense on the opposite side of the body.dissociated anesthesia (dissociation anesthesia) loss of perception of certain stimuli while that of others remains intact.electric anesthesia anesthesia induced by passage of an electric current.endotracheal anesthesia anesthesia produced by introduction of a gaseous mixture through a tube inserted into the trachea.epidural anesthesia regional anesthesia produced by injection of the anesthetic agent into the epidural space. It may be performed by injection of the agent between the vertebral spines in the cervical, thoracic, or lumbar regions. An old method was anesthesia" >caudal anesthesia, which involved injecting the agent into the sacral hiatus. Called also epidural block.general anesthesia a state of unconsciousness produced by anesthestic agents, with absence of pain sensation over the entire body and a greater or lesser degree of muscular relaxation; the drugs producing this state can be administered by inhalation, intravenously, intramuscularly, or rectally, or via the gastrointestinal tract.gustatory anesthesia loss of the sense of taste.hysterical anesthesia loss of tactile sensation occurring as a symptom of conversion disorder, often recognizable by its lack of correspondence with nerve distributions.infiltration anesthesia local anesthesia produced by injection of the anesthetic solution directly into the area of terminal nerve endings. Called also infiltration analgesia.inhalation anesthesia anesthesia produced by the respiration of a volatile liquid or gaseous anesthetic agent.insufflation anesthesia anesthesia produced by introduction of a gaseous mixture into the trachea through a tube.local anesthesia that produced in a limited area, as by injection of a local anesthetic or by freezing with ethyl chloride.open anesthesia general inhalation anesthesia in which there is no rebreathing of the exhaled gases.paraneural anesthesia perineural block.paravertebral anesthesia regional anesthesia produced by the injection of a local anesthetic around the spinal nerves at their exit from the spinal column, and outside the spinal dura. Called also paravertebral block.perineural anesthesia perineural block.peripheral anesthesia lack of sensation due to changes in the peripheral nerves.rectal anesthesia anesthesia produced by introduction of the anesthetic agent into the rectum.refrigeration anesthesia cryoanesthesia.regional anesthesia insensibility caused by interrupting the sensory nerve conductivity of any region of the body; the two primary types are field block, the encircling of an operative field by means of injections of a local anesthetic and nerve block, the making of injections in close proximity to the nerves supplying the area. Called also block.saddle block anesthesia block" >saddle block.segmental anesthesia loss of sensation in a segment of the body due to a lesion of a nerve root.spinal anesthesia anesthesia due to a spinal lesion.regional anesthesia produced by injection of the agent beneath the membrane of the spinal cord. Called also spinal block.surgical anesthesia that degree of anesthesia at which operation may safely be performed.tactile anesthesia loss of the sense of touch" >touch.topical anesthesia that produced by application of a local anesthetic directly to the area involved.

seg·men·tal an·es·the·si·a

loss of sensation limited to an area supplied by one or more spinal nerve roots.

seg·men·tal an·es·the·si·a

(seg-men'tăl an'es-thē'zē-ă) Loss of sensation limited to an area supplied by one or more spinal nerve roots.

seg·men·tal an·es·the·si·a

(seg-men'tăl an'es-thē'zē-ă) Loss of sensation limited to area supplied by one or more spinal nerve roots.