For intramuscular injection, the nurse should insert the needle into the muscle at an angle of?

WCL Staff Nurse - 2019

Nursing Foundation

Easy

Appeared in: WCL Staff Nurse - 2019

Explanation

The correct angle for an intramuscular (IM) injection is 90 degrees, as confirmed by the provided image and standard nursing guidelines.
This perpendicular angle ensures the needle passes through the superficial layers (skin and subcutaneous fat) to deposit medication deep within the muscle tissue.
Deep muscle tissue has a rich blood supply, which allows for faster and more predictable medication absorption compared to other routes like subcutaneous.

Option A: A 15-degree angle is too shallow for an intramuscular injection and would result in the medication being deposited in the dermis.
Option B: A 30-degree angle is not a standard, recommended angle for any of the primary parenteral injection routes.
Option C: A 45-degree angle would likely deposit the medication into the subcutaneous tissue rather than the muscle, leading to slower absorption and potential tissue irritation.

Clinical Relevance

Nursing practice connection: Knowing Parenteral Injection Techniques helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Using the correct needle angle is critical for patient safety and medication efficacy. An incorrect angle can lead to injecting medication into the wrong tissue layer, causing pain, nerve damage, poor absorption, or sterile abscesses.
For IM injections, especially with irritating medications, the Z-track method is recommended. This technique involves displacing the skin before injection to seal the medication in the muscle and prevent it from leaking into the subcutaneous tissue.
What if? If the patient was very thin or emaciated, the IM angle would still be 90 degrees, but the nurse must use a shorter needle and carefully select the site (e.g., ventrogluteal) to avoid hitting bone. For a subcutaneous injection in the same patient, a 45-degree angle would be safer than 90 degrees.

How to Approach the Question

First, identify the key terms in the question: "intramuscular injection" and "angle".
This is a direct recall question about a fundamental nursing procedure. Access your knowledge of parenteral medication administration.
Visualize or recall the different injection routes and their purposes. Intramuscular (IM) injections are intended to reach deep into the muscle.
Associate the 90-degree (perpendicular) angle with the need to go "straight in" to penetrate the skin and fat layers to reach the muscle.
Contrast this with other standard angles: a very shallow angle (10-15°) for intradermal and a 45° angle for subcutaneous injections.
Evaluate the options and select the one that matches the standard for intramuscular injections.

Concept Tested & Keywords

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