What angle should a nurse inject medication for an intramuscular injection into the deltoid muscle?

For an intramuscular injection into the deltoid muscle, the appropriate angle of injection is 90 degrees. This angle allows for the medication to be deposited directly into the muscle tissue, ensuring optimal absorption and effectiveness.

When administering an intramuscular injection, the goal is to deliver the medication deep into the muscle layer, where it can be absorbed into the bloodstream efficiently. A 90-degree angle facilitates this by ensuring that the needle enters perpendicular to the skin, minimizing the risk of injecting the medication into subcutaneous tissue or other unintended layers.

Other angles, such as 45 degrees or 60 degrees, are typically used for subcutaneous injections, where medication is intended to be administered into the fatty tissue just beneath the skin, rather than into a muscle. A 30-degree angle is also more appropriate for those subcutaneous injections, and therefore is not suitable for intramuscular injections, which require the needle to penetrate deeper.