epidural injection

ep·i·dural in·jec·tion

(ep'i-dūr'ăl in-jek'shŭn)

Subcutaneous or intramuscular injection of a pharmacotherapeutic or anesthetic agent into the epidural space.

epidural injection

The injection of anesthetic solution or other medicines into the epidural space of the spinal cord.

See also: injection

injection

1. the forcing of a liquid into a part, as into the subcutaneous tissues, the vascular tree, or an organ.

2. a substance so forced or administered; in pharmacy, a solution of a medicament suitable for injection.

3. congestion.

4. immunizing substances, or inoculations, are generally given by injection. When a patient is unconscious, injection may be the only means of administering medication, and in some cases nourishment. Some medicines cannot be given by mouth because chemical action of the digestive juices or of hepatic enzymes would change or reduce their effectiveness, or because they would be removed from the body too quickly to have any effect. Certain potent medicines must be injected because they would irritate body tissues if administered any other way. A medication may be injected so that it will act more quickly.

In addition to the most common types of injections described below, injections are sometimes made under the conjunctiva, into arteries, bone marrow, the spine, the sternum, the pleural space of the chest region, the peritoneal cavity and joint spaces.

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injection collar

a collar carrying an injection device which can be triggered from a remote site.

epidural injection

see epidural.

hypodermic injection

subcutaneous injection.

intradermal injection, intracutaneous injection

injection of small amounts of material into the corium or substance of the skin. This method is used in diagnostic procedures and in administration of regional anesthetics, as well as in treatment procedures. In certain allergy tests, the allergen is injected intracutaneously. These injections are given in an area where the skin and hair are sparse, usually on the inner part of the thigh in dogs or the caudal fold in cows. A small-gauge needle is recommended and it is inserted at a 10- to 15-degree angle to the skin.

intramuscular injection

injection into the substance of a muscle, usually the thigh or pectoral muscle, or the muscle of the neck or rump. Intramuscular injections are given when the substance is to be absorbed quickly. They should be given with extreme care, especially in the thigh, because the sciatic nerve may be injured or a large blood vessel may be entered if the injection is made without drawing back on the syringe first.

intraperitoneal injection

liquid injection, usually of antibacterial agent, rarely anesthetic or euthanatizing agents, administered to obtain systemic blood levels of the agent; faster than subcutaneous or intramuscular injection and used when veins not accessible. The needle is introduced into the upper flank and the syringe plunger withdrawn to ensure that intestine has not been penetrated. The injected solution should run freely.

intratesticular injection

a method of administering a general anesthetic agent to boars for castration.

intravenous injection

an injection made into a vein. Intravenous injections are used when rapid absorption is called for, when fluid cannot be taken by mouth, or when the substance to be administered is too irritating to be injected into the skin or muscles. In certain diagnostic tests and x-ray examinations, a drug or dye may be administered intravenously. Blood transfusions also are given by this route. See also intravenous infusion.

subarachnoid injection

the risk of injection is greatest at the atlanto-occipital space where the vertebral venous plexus is most likely to be lacerated.

subcutaneous injection

injection made into the subcutaneous tissues; called also hypodermic injection. Although usually fluid medications are injected, occasionally solid materials, such as steroid hormones, are administered subcutaneously in small, slowly absorbed pellets to prolong their effect. Subcutaneous injections may be given wherever there is subcutaneous tissue, usually in the loose skin on the side of the chest or in the flank. The amount injected should not exceed 2 ml for cats and small dogs, 5 ml for large dogs and 20 ml for horses. Cows are often given 200 ml because of their very loose skin. The needle is held at a 45-degree angle to the skin.