What Is a Deltoid Intramuscular Injection?

A deltoid intramuscular injection is a shot administered directly into the muscle tissue of the upper arm. This is a popular location for injections in adults because it is easy to access and is suitable for a range of types of medications. The volume of medication that can be administered via this route is limited, an important consideration if a patient needs a large dose. Typically no more than 2 milliliters of a drug can be injected at a time in this location, and for young patients, even this may be too much.

To administer a deltoid intramuscular injection, a care provider swabs the site to sterilize it and prepares the injection. This may require drawing the medication up into the needle, or using a pre-packaged product that contains medication in a syringe ready for use. With a gloved hand, the care provider carefully handles the tissues of the upper arm to find the deltoid muscle, and inserts the needle at a 90° angle directly into the middle of the muscle.

Needle size can depend on the injection being given; a larger needle may be needed for something like a thick suspension. It also needs to be long enough to reach the muscle below the layer of subcutaneous tissue. Once the needle is properly placed, the plunger can be slowly depressed to distribute the medication into the muscle. Giving a deltoid intramuscular injection too quickly can cause injury, especially with thick drugs that don’t flow easily.

Locating the deltoid muscle can be challenging for people without injection experience, although skilled care providers can usually find it quickly. The site allows medication to be absorbed quickly and efficiently through the muscle. There is a risk of damaging the brachial artery or radial nerve, which makes it important to place the injection with care and pay attention to indicators from the patient that it may be in the wrong place. A deltoid intramuscular injection can sting, but intense pain or significant bleeding are signs of a problem.

Medications administered via deltoid intramuscular injection should be nonirritating. If a compound is known to cause irritation, it may need to be injected into a different site, like the buttocks or leg. In some cases, a medication must be administered in a specific location, in which case directions will include a reminder that it is not safe to change spots. people giving themselves injections at home to manage a condition may prefer the thigh as an injection site if the placement doesn’t matter, because the leg is easy to see and any bruising or marks won’t be readily visible.