The gluteus maximus is the big muscle in the buttocks.
An intramuscular gluteal injection – commonly referred to colloquially as a shot – is the administration of medication via a hypodermic syringe into the ventrogluteal or dorsogluteal muscle. These two areas of the large gluteus muscle can be used safely and easily for intramuscular (IM) injections due to the large size of the muscle and the relative lack of adjacent nerves or blood vessels to complicate the process. The ventrogluteus muscle is located on the ventral, or lateral, surface of the body, while the dorsogluteus muscle is found along the dorsal or posterior surface of the body. The dorsogluteus muscle then lies just above the buttocks. This last muscle is the best-known injection site and the one most thought of when gluteal intramuscular thermoinjection is used.
Very thin, elderly, or underweight patients may not have enough arm muscles to safely consider the deltoid as an injection site.
Antibiotics, hormones, vaccines, sedatives, and analgesics are routinely administered by intramuscular injection into the buttocks, depending on the permissible means of administration for the specific drug. Prior to the widespread use of patient-controlled administration (PCA) intravenous pumps for analgesics, most postoperative pain was controlled by intramuscular gluteal injection into the dorsal or ventral aspect of the muscle. Patients often complained that the side effects of their painkiller injections rivaled the post-operative pain itself.
The dorsogluteal muscle is the most commonly known injection site.
The gluteal intramuscular injection sites – the dorso-gluteal and ventrogluteal – combine with the deltoid muscle of the arm and the vastus lateralis of the thigh to provide eight potential sites for an IM injection. However, it is necessary to exercise good nursing judgment when choosing an appropriate injection site. Very thin, elderly, or underweight patients may not have enough arm muscles to safely consider the deltoid as an injection site. This type of injection should not be used on infants and children under three years of age due to inadequate muscle development in the region. Authorities recommend that IM injections into the gluteal area be spaced at least 1 inch (about 2.5 cm) apart to avoid scarring or fistula formation, thus limiting the number of available IM sites.
Potential and appropriate intramuscular sites are also limited in accessibility. Cast patients will not be able to receive an intramuscular injection into the buttocks due to the plaster coverage area. In addition, patients who necessarily self-administer an IM injection will have to use both vastus lateralis muscles to properly visualize the area. After sterilizing the chosen injection site with an alcohol wipe, the nurse should smooth the skin area with a gloved hand and immediately insert the needle at a right angle to the skin surface. After withdrawing the plunger slightly to ensure that the vein has not been punctured, the plunger should be continuously depressed until the drug is completely delivered.