The appropriate needle size for subcutaneous injection is:

DSSSB October 2024

Nursing Foundation

Easy

Appeared in: DSSSB October 2024

Explanation

Subcutaneous (SUBQ) injections deliver medication into the fatty tissue layer (adipose tissue) located just below the skin.
This route requires a fine, short needle to minimize patient discomfort, pain, and tissue trauma.
A 27-gauge needle falls within the recommended range of 25-G to 31-G for SUBQ injections, ensuring proper medication delivery for slow, sustained absorption.
The higher the gauge number, the smaller the diameter of the needle.

Option A: A 10-gauge needle is an extremely large-bore needle, which would cause excessive pain and tissue damage if used for a subcutaneous injection.
Option C: A 22-gauge needle is thicker than what is recommended for subcutaneous injections and is more likely to cause bruising and discomfort.
Option D: An 18-gauge needle is a large-bore needle that would cause significant pain and tissue trauma. It is not appropriate for delivering medication into the delicate subcutaneous tissue.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Needle gauge selection for subcutaneous injections as background academic context rather than a clinical decision trigger.
Selecting the correct needle gauge is a critical nursing responsibility that directly impacts patient safety, comfort, and the therapeutic effectiveness of the medication.
Using a needle that is too large for a subcutaneous injection can cause unnecessary pain, bruising, hematoma formation, and may result in the medication being delivered into the muscle, leading to faster absorption than intended (e.g., with insulin, this could cause hypoglycemia).
What if? If a patient is obese, a longer needle (e.g., 5/8 inch) might be needed to reach the subcutaneous tissue, but the gauge should still be fine (e.g., 25G or 27G). Conversely, for a very thin patient, a shorter needle (e.g., 3/8 inch) and a 45-degree angle are preferred to avoid hitting the muscle.

How to Approach the Question

First, identify the core of the question, which is asking for the correct needle size for a 'subcutaneous injection'.
Recall the principle of needle gauges: a larger gauge number corresponds to a smaller needle diameter.
Remember that subcutaneous tissue is delicate, so a fine (small diameter, high gauge number) needle is required for patient comfort and proper medication delivery.
Evaluate the options: 10 G and 18 G are very large-bore needles used for rapid fluid/blood administration. 22 G is an intermediate size, often for IM use. 27 G is a fine needle.
Select 27 G as it falls within the typical recommended range (25-31 G) for subcutaneous injections.

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