What should NOT be done when administering vaccines, insulin, or heparin?

When administering vaccines, insulin, or heparin, it is crucial to understand the best practices for effective and safe injection techniques. Aspirating the syringe, which involves pulling back on the plunger after inserting the needle but before injecting the medication, was once a common practice to check for blood return, indicating that the needle may have entered a blood vessel. However, contemporary guidelines and current training standards indicate that this step is not necessary and may even lead to discomfort for the patient.

The rationale behind omitting aspiration in these specific injections lies in the anatomy and delivery method involved. For subcutaneous injections, such as insulin and heparin, the goal is to deliver medication into the fat layer beneath the skin, which typically does not have large blood vessels. Consequently, it is unlikely that aspiration will show blood, and performing this action could increase the risk of pain and bruising at the injection site without providing any real benefit.

In contrast, the other practices mentioned—injecting at a 90-degree angle, rotating the injection site, and administering the injection quickly—are all endorsed as part of proper technique. Injecting at a 90-degree angle ensures that the medication is delivered into the muscle for intramuscular injections or into the subcutaneous layer