The nurse is to administer 3 mL of medication intramuscularly to an adult patient. Which is the appropriate site for the injection?

Choice A rationale:

The dorsal gluteal site (also known as the dorsogluteal site) was previously a common injection site, but it's now not recommended due to several significant risks:

Proximity to the sciatic nerve: The sciatic nerve is the largest nerve in the body, and it runs close to the dorsal gluteal site. Accidental injection into or near the nerve can cause severe pain, nerve damage, and potential paralysis.

Difficulty in locating landmarks: The landmarks for the dorsal gluteal site can be difficult to locate accurately, especially in obese patients or those with decreased muscle mass. This increases the risk of injecting into the wrong area.

Risk of injury to blood vessels: The dorsal gluteal site also has a higher risk of injury to blood vessels, as several large vessels run through the area.

Choice B rationale:

The deltoid muscle is located in the upper arm and is a common site for intramuscular injections, but it has limitations for larger volumes:

Small muscle size: The deltoid muscle is relatively small compared to other IM injection sites. It's generally recommended for smaller volumes of medication (up to 1 mL in adults).

Subcutaneous tissue: The deltoid muscle often has a layer of subcutaneous tissue (fat) that can hinder absorption of medication.

Choice C rationale:

The vastus lateralis muscle is the preferred site for intramuscular injections in adults for several reasons:

Large muscle size: It's a large, thick muscle that can accommodate larger volumes of medication (up to 5 mL in adults). Easy to locate landmarks: The landmarks for the vastus lateralis are easy to identify, even in obese patients.

Few major nerves or blood vessels: It has fewer major nerves or blood vessels in the area, reducing the risk of injury. Pain tolerance: It's generally considered to be a less painful injection site than the deltoid or dorsogluteal sites.

Choice D rationale:

The lateral piriformis muscle is not a recognized or recommended site for intramuscular injections. It's a deep muscle located in the buttocks, and injecting into it would be difficult and potentially dangerous due to its proximity to the sciatic nerve and other important structures.