Final answer:
The optimal needle length for a subcutaneous injection is typically 5/8 inch, which balances proper medication delivery into the fatty tissue without reaching the muscle. Needle size choices may depend on individual patient factors.
Step-by-step explanation:
The best length needle to provide a subcutaneous injection is generally C) 5/8 inch. The selection of needle length is crucial to ensure that the medication is administered into the fatty tissue layer beneath the skin, without reaching the muscle tissue.
Subcutaneous injections are commonly given using needles that are short and thin, ranging in length from about 5/8 inch to 1/2 inch. A 5/8 inch needle is typically adequate for most patients and is commonly used because it is long enough to penetrate the subcutaneous tissue, but not so long that it would reach the muscles. Factors such as the patient's body type and the injection site may influence the choice, but for most adults, a 5/8 inch needle is the standard size for a subcutaneous injection.
Using a needle that is too short may result in the medication being deposited into the epidermis, where it's ineffective, while a needle that's too long might reach the muscle tissue, turning the subcutaneous injection into an intramuscular one, which is not desired in this case.