A gluteal intramuscular injection — commonly referred to colloquially as a shot — is the administration of medication using a hypodermic syringe into either the ventrogluteal or the dorsogluteal muscle. These two areas of the large gluteal muscle can both 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 ventrogluteal muscle is located on the ventral aspect, or side, of the body while the dorsogluteal muscle lies along the body's dorsal, or rear aspect. The dorsogluteal muscle, then, is found just above the buttocks. This latter muscle is the most commonly known injection site and the one most often thought of when the term gluteal intramuscular injection is used.
Antibiotics, hormones, vaccinations, sedatives and pain medications are routinely administered by gluteal intramuscular injection, depending upon the specific drug's allowable means of administration. Prior to the widespread use of patient-controlled administration (PCA) intravenous pumps for pain medication, most post-operative pain was controlled by gluteal intramuscular injection into either the dorsal or ventral aspect of the muscle. Patients often complained that the after-effects of their pain medication injections rivaled that of their postoperative pain itself.
Gluteal intramuscular injection sites — the dorsogluteal and ventrogluteal — combine with the upper arm's deltoid muscle and the thigh's vastus lateralis to provide eight potential sites for an IM injection. Sound nursing judgment needs to be exercised when choosing an appropriate injection site, however. Very thin, aged or underweight patients may not have enough upper arm muscle to safely consider the deltoid as an injection site. This type of injection should not be used for infants and children less than three years old due to inadequate muscular development in the area. Authorities recommend that IM injections in the gluteal area be spaced at a minimum of 1 inch (about 2.5 cm) intervals to avoid scarring or fistula development, thereby limiting the number of available IM sites.
Potential and appropriate intramuscular sites are also limited as to accessibility. Patients in a spica cast will not be able to receive a gluteal intramuscular injection because of the cast coverage area. Further, patients who necessarily self-administer an IM injection will have to use both vastus lateralis muscles in order to adequately visualize the area. After sterilizing the chosen injection site with an alcohol prep pad, the nurse should smooth the skin area with a gloved hand and promptly insert the needle at a right angle to the skin surface. After withdrawing the plunger slightly to ensure that a vein was not punctured, the plunger should be steadily depressed until the medication is completely administered.