What is the recommended needle size for adults and children for intramuscular injections?

• A. For adults: 22 gauge, 1 to 1-1.2 inches; For children: 25 gauge, 1 inch.
• B. For adults: 25 gauge, 1 inch; For children: 22 gauge, 1 to 1.2 inches.
• C. For adults: 22 gauge, 1 to 1-1.2 inches; For children: 25 gauge, 1 inch.
• D. For adults: 24 gauge, 0.5 inch; For children: 27 gauge, 0.5 inch.

Answer: (C)

Selecting the right needle size for intramuscular injections depends on reaching the muscle while minimizing tissue trauma, and age/body size guides the gauge and length.

For adults with average muscle mass, a 22-gauge needle about 1 to 1-1/4 inches long is typical. The 22-gauge bore balances smooth medication flow with a manageable size for most meds, and the length is usually enough to reach muscle depth beyond subcutaneous tissue.

For children, a thinner needle and shorter length are generally used, such as 25 gauge with about 1 inch in length. The smaller bore helps reduce pain and tissue disruption, and the 1-inch length is typically sufficient to reach muscle in pediatric patients.

Other options mix gauges and lengths in ways that don’t align with common practice, such as using a shorter length or a much thinner needle for adults or a longer needle for children, which can risk not reaching muscle or increasing discomfort.