intramuscular injection

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injection

 [in-jek´shun]
2. the forcing of a liquid into a part, as into the subcutaneous tissues, the vascular tree, or an organ.
3. a substance so forced or administered; in pharmacy, a solution of a medicament suitable for injection.

Immunizing substances, or inoculations, are generally given by injection. Some medicines cannot be given by mouth because chemical action of the enzymes and digestive fluids would change or reduce their effectiveness, or because they would be removed from the body too quickly to have any effect. Occasionally a medication is injected so that it will act more quickly. In addition to the most common types of injections described below, injections are sometimes made into arteries, bone marrow, the spine, the sternum, the pleural space of the chest region, the peritoneal cavity, and joint spaces. In sudden heart failure, heart-stimulating drugs may be injected directly into the heart (intracardiac injection).
Sites for injections. A, subcutaneous injection sites. B, intramuscular injection site for children in the vastus lateralis muscle. C, D, and E, intramuscular injection sites for adults: C, deltoid muscle injection site. D, injection site in the buttock (dorsogluteal site). E, injection site in the anterolateral thigh (ventrogluteal site).
hypodermic injection subcutaneous injection.
intracutaneous injection intradermal injection.
intracytoplasmic sperm injection (ICSI) a micromanipulation technique used in male factor infertility; a single spermatocyte is inserted into an oocyte by micropuncture.
intradermal injection injection of small amounts of material into the corium or substance of the skin, done 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 forearm. A 25-gauge needle, about 1 cm long, is usually used and is inserted at a 10- to 15-degree angle to the skin.
intramuscular injection injection into the substance of a muscle, usually the muscle of the upper arm, thigh, or buttock. Intramuscular injections are given when the substance is to be absorbed quickly. They should be given with extreme care, especially in the buttock, because the sciatic nerve may be injured or a large blood vessel may be entered if the injection is not made correctly into the upper, outer quadrant of the buttock. The deltoid muscle at the shoulder is also used, but less commonly than the gluteus muscle of the buttock; care must be taken to insert the needle in the center, 2 cm below the acromion.

Injections into the anterolateral aspect of the thigh are considered the safest because there is less danger of damage to a major blood vessel or nerve. The area permits multiple injections, is more accessible, and is easier to stabilize, particularly in pediatric patients or others who are restless and uncooperative. The vastus lateralis muscle is located by identifying the trochanter and the side of the knee cap and then drawing a visual line between the two. The distance is then divided into thirds and the needle inserted into the area identified as the middle third.

The needle should be long enough to insure that the medication is injected deep into the muscle tissue. The gauge of the needle depends on the viscosity of the fluid being injected. As a general rule, not more than 5 ml is given in an intramuscular injection for an adult. The maximum for an infant is 0.5 ml, and the injection is made into the vastus lateralis muscle. The needle is inserted at a 90-degree angle to the skin. When the gluteus maximus muscle is the site chosen for the injection, the patient should be in a prone position with the toes turned in if possible. This position relaxes the muscle and makes the injection less painful.
intrathecal injection injection of a substance through the theca of the spinal cord into the subarachnoid space. Patients receiving intrathecal chemotherapy for metastatic malignancy of the central nervous system should maintain a flat or Trendelenburg position for one hour after treatment to achieve optimum distribution of the drug.
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. (See also intravenous infusion.)
jet injection injection of a drug in solution through the intact skin by an extremely fine jet of the solution under high pressure.
subcutaneous injection injection made into the subcutaneous tissues. Although usually fluid medications are injected, occasionally solid materials such as steroid hormones may be injected in small, slowly absorbed pellets to prolong their effect. Subcutaneous injections may be given wherever there is subcutaneous tissue, usually in the upper outer arm or thigh. A 25-gauge needle about 2 cm long is usually used, held at a 45-degree angle to the skin, and the amount injected should not exceed 2 ml in an adult. Subcutaneous insulin injections may be given at a 90-degree angle with an insulin syringe. Called also hypodermic injection.
Angle of needle insertion for administering a subcutaneous injection. From Lammon et al., 1995.
Z-track injection see z-track injection.

intramuscular injection

Etymology: L, intra + musculus
the introduction of a hypodermic needle into a muscle to administer a medication.
method The equipment is selected, and the medication drawn up into the syringe. The selected site is prepared by cleansing with alcohol. The sites most commonly used are the upper outer quadrant of the gluteal area, the ventrogluteal area, the vastus lateralis of the thigh, or the deltoid muscle. Care must be taken to identify landmarks and select sites to prevent damage to nerves and adjacent structures. The skin is stretched between the thumb and forefinger. The needle is introduced at a 90-degree angle to the muscle with a quick thrust and advanced as necessary-not as far as the hub of the needle, but deep into the muscle. The plunger is withdrawn slightly to be sure that the needle has not been placed in a blood vessel. The solution is injected slowly, the needle is withdrawn, and the injection site is massaged unless contraindicated.
interventions If the gluteal area is chosen, the patient is asked to lie prone with ankles bent and feet curved in, so that the toes of each foot are directed toward the opposite foot to relax the gluteal muscles, thus making the injection less painful. Injection into deltoid muscles is more painful than in other sites and is avoided if possible. The ventrogluteal area and the vastus lateralis are the preferred injection sites in infants. Care is taken not to hit the femur with the tip of the needle when injecting into the vastus lateralis. Needles and syringes are always disposed of safely in a puncture-resistant container without recapping.
outcome criteria Infection may result from nonaseptic technique; care is taken not to contaminate the needle before injection or to suffer a needlestick. Certain medications can cause tissue necrosis if injected into the subcutaneous tissues. Many medications may be given intravenously or intramuscularly, but the intravenous dose may be much smaller. Inadvertent injection into a blood vessel can cause severe systemic reactions of an overdose. Often biologicals, such as antigens, serums, or vaccines, may leave a knot in the muscle that is not painful and that subsides slowly over several weeks or months, though it may cause concern in the patient or in the parents of younger patients. The lump should not grow larger or become more painful. If it does, one may assume that an abscess has formed.
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Intramuscular injection in the vastus lateralis muscle

in·tra·mus·cu·lar in·jec·tion

(IMI) (in'tră-mŭsk'yū-lăr in-jek'shŭn)
Injection of fluid into deep muscle. Usual sites for intramuscular injections include ventrogluteal, vastus lateralis, and deltoid muscles. Absorption is faster than subcutaneous and up to 3 mL can be given by this method.

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.

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

intramuscular

within the substance of a muscle.

intramuscular injection
see intramuscular injection.