Final answer:
The nurse is using the distraction method by engaging the child's imagination, presenting the syringe as a space rocket to reduce the anxiety of receiving an injection.
Step-by-step explanation:
The pain management technique the nurse is using with the 5-year-old boy who must receive repeated intravenous injections is called distraction. Distraction is a method where the patient's attention is diverted away from the procedure and towards something more pleasant or less anxiety-inducing, often through imaginative engagement or play. In this case, the nurse is presenting the syringe as a space rocket to divert the child's attention from the injection itself and to make the experience less frightening for him.
Desensitization, also known as hyposensitization, is a different type of treatment where a patient is exposed to gradually increasing doses of an allergen with the aim of inducing tolerance to that allergen. Epinephrine is often used in emergency treatment for severe allergic reactions, as it can help reduce the severity of the hypersensitivity response. However, this is not what is being described in the scenario with the nurse and the child.