Mnemonic for Needle Gauge & Sizes by Picmonic

SUBQ injections penetrate through the dermis directly into the subcutaneous tissue. They are often used for injections like insulin and heparin. Remember, you can give SUBQ injections at 45 or 90 degrees in areas like the upper arms, abdomen, or anterior thighs.

You can always remember to use a smaller needle size for SUBQ injections, like a 3/8 or 5/8 inch, by remembering that you would never want a 3-inch long needle injected into your abdomen.

IM injections penetrate directly into the vascular muscles like the deltoid, ventrogluteal, or vastus lateralis. Because of the depth of muscle beneath the subcutaneous tissue, remember to select a longer needle. Obese patients may require up to 3-inch long needles. Ouch!

Adults, on average, require needle sizes of 1-1.5 inches in length. Obese patients sometimes require up to a 3-inch-long needle to penetrate the additional adipose tissue. Be sure to consider a smaller needle for smaller patients, like children and thinner adults. This consideration is especially important for elderly patients with atrophied muscles. These patients may only require a 1/2 to 1-inch needle to reach the muscle.