What angle is used to administer an intramuscular injection into the deltoid?

What angle is used to administer an intramuscular injection into the deltoid?

• A. 45 degrees
• B. 60 degrees
• C. 90 degrees
• D. 120 degrees

Answer: (C)

Penetrate the deltoid muscle with a perpendicular, 90-degree angle to the skin. This straight-in approach places the needle directly into muscle tissue, ensuring the medicine is deposited where it can be absorbed efficiently. If the angle is too shallow, such as 45–60 degrees, the injection may lodge in subcutaneous fat and not reach the muscle, leading to slower or unpredictable absorption. An angle like 120 degrees wouldn’t reliably enter the muscle and could result in improper delivery or tissue irritation. When performing the injection, identify the deltoid site about two to three fingerbreadths below the acromion and use a needle length appropriate for the patient so the needle can reach the muscle at that 90-degree angle.

Penetrate the deltoid muscle with a perpendicular, 90-degree angle to the skin. This straight-in approach places the needle directly into muscle tissue, ensuring the medicine is deposited where it can be absorbed efficiently. If the angle is too shallow, such as 45–60 degrees, the injection may lodge in subcutaneous fat and not reach the muscle, leading to slower or unpredictable absorption. An angle like 120 degrees wouldn’t reliably enter the muscle and could result in improper delivery or tissue irritation. When performing the injection, identify the deltoid site about two to three fingerbreadths below the acromion and use a needle length appropriate for the patient so the needle can reach the muscle at that 90-degree angle.