Intramuscular injections are used for antibiotics, hormones and vaccines that need to be released slowly, notes Carol Taylor, R.N., Phd.D, author of “Nursing Fundamentals. To avoid injury to underlying nerves and blood vessels, the person administering the injection selects one of several approved sites in the thigh, upper arm or hip. The choice of site depends on the patient's age and muscle development, as well as on the type and volume of the medication. Bony landmarks help to identify the area of the muscle that is safe for injection.
Ventrogluteal Site
The ventrogluteal site on the hip is appropriate for adults because the muscle is large and relatively free of major blood vessels and nerves. The patient may lie on his side, back or abdomen. The person giving the injection uses the greater trochanter--or hipbone--as a landmark. He places the palm of his opposite hand--left hand on right hip or right hand on left hip--over the hipbone with his fingers pointing toward the patient's head. He places his index finger on the anterior superior iliac spine--pelvic bone--and his middle finger on the iliac crest, forming a triangle over a portion of the outer hip. The proper site for the injection is in the center of the triangle.
Vastus Lateralis Site
The vastus lateralis muscle in the upper outer thigh is suitable for infants and young children because no large nerves or blood vessels are at risk for injury. It is also appropriate for adults who self-administer intramuscular medications. Using the hip bone and the knee as landmarks, the person giving the injection mentally divides the area between the bones into thirds both horizontally and vertically, according to Drugs.com. The correct injection site is in the outer middle third of the thigh.
Deltoid Site
The deltoid muscle in the upper part of the arm is used only for adults and older children with sufficient muscle mass, according to Taylor. The patient may stand, sit or lie down. The person giving the injection uses the acromion process--the bone at the top of the upper arm--as a landmark. Palpating the lower edge of the acromion process and spreading her fingers, she forms an upside-down triangle with the acromion process as the base. The point of the triangle is at the level of the patient’s armpit, at the side of the upper arm, directly below the middle of the base of the triangle. The injection is given in the center of the triangle, one to two inches below the acromion process. The deltoid is the site of choice for administration of vaccines, except in infants and small children, according to the Centers for Disease Control and Prevention.
Dorsogluteal Site
A fourth site, the dorsogluteal muscle or upper outer buttock, notes Taylor, is no longer recommended because of the risk of sciatic nerve injury.
References
- "Fundamentals of Nursing"; Carol R. Taylor, Ph.D., et al; 2008
- Drugs.com: How to Give an Intramuscular Injection
- Centers for Disease Control and Prevention: Vaccines
