Final answer:
The nurse should first report the signs of potential infection or inflammation at the IV site to a clinician and follow the protocol, which may involve removing the IV cathenter to prevent further issues.
Step-by-step explanation:
When a nurse identifies erythema, warmth, and mild edema at an intravenous (IV) site, along with a patient reporting tenderness, the first step should be to assess for a potential infection or an inflammation response. The nurse should then report these findings to the primary care clinician and follow the facility's protocol which may include removing the IV catheter to prevent further irritation or infection. The clinical focus implies that redness, swelling, warmth, and pain can be signs of an infection, thus, timely intervention is essential to avoid complications like necrotizing fasciitis or systemic infections that could lead to sepsis, which is a life-threatening condition.