Loss of sensation induced in a limited region of the body to prevent pain during examinations, diagnostic or treatment procedures, and surgical operations. Local anaesthesia is produced by the administration of drugs that temporarily interrupt the action of pain-carrying nerve fibres. Local anaesthetics applied topically before injections or blood tests include sprays and skin creams and ointments. These are often used for children. For minor surgical procedures, such as stitching of small wounds, local anaesthesia is usually produced by direct injection into the area to be treated. To anaesthetize a large area, or when local injection would not penetrate deeply enough into body tissues, a nerve block may be used. Nerves can also be blocked where they branch off from the spinal cord, as in epidural anaesthesia, which is widely used in childbirth, and spinal anaesthesia, which is used for surgery on the lower limbs and abdomen. Serious reactions to local anaesthetics are uncommon. Repeated use of topical preparations may cause allergic rashes.
Anaesthesia, local |
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