Final answer:
The characteristic specifically associated with a subcutaneous injection of 5,000 units of heparin is the 90-degree angle of insertion, which ensures proper administration into the subcutaneous tissue.
Step-by-step explanation:
Which characteristic is associated with a subcutaneous injection of 5,000 units of heparin? The characteristic associated with a subcutaneous injection of heparin is a 90-degree angle of insertion. This is because subcutaneous injections involve inserting a needle into the fatty tissue just beneath the skin, not into a muscle or vein, and a 90-degree angle ensures that the medication is properly administered into the subcutaneous tissue. Other options such as 3-mL syringe, 22-gauge needle, and 1 1/2 inch needle length could be plausible, but they are not unique to heparin and could vary based on other factors, like the specific injection technique or patient's body habitus.When administering a subcutaneous injection, the needle is inserted at a 90-degree angle into the layer of fat just below the skin. This angle helps ensure proper delivery of the medication into the subcutaneous tissue.