Final answer:
When administering heparin subcutaneously, the nurse should use a small-gauge needle and insert it at a 90-degree angle to the skin. Gentle pressure should be applied to the injection site after administration to minimize bleeding.
Step-by-step explanation:
When administering heparin subcutaneously, the nurse should use a small-gauge needle and insert it at a 90-degree angle to the skin. This ensures proper delivery of the medication into the fatty tissue under the skin. It is important to apply gentle pressure to the injection site after administration to minimize bleeding.