A nurse is observing the IV catheter insertion site of a client who is receiving continuous IV therapy. Which of the following manifestations should the nurse identify as an indication that the client has developed phlebitis?

Choice A rationale Erythema (redness) is a classic sign of phlebitis, which is the inflammation of the vein's inner wall (tunica intima). This redness is a direct result of the local inflammatory response, characterized by vasodilation and increased blood flow to the affected area, often accompanied by pain and warmth along the course of the vein due to chemical mediators. Choice B rationale Pallor (paleness) at the IV insertion site or surrounding skin is often a manifestation of infiltration or extravasation, where non-vesicant or vesicant fluid, respectively, leaks into the subcutaneous tissue, causing edema and compressing local vasculature, reducing superficial blood flow. Phlebitis typically presents with visible inflammation. Choice C rationale Coolness at the IV insertion site is a key indicator of infiltration or extravasation, resulting from the infusion of room temperature or cooled fluid into the interstitial space. This sensation of coolness is in direct contrast to the warmth that is classically associated with the localized inflammation characteristic of phlebitis. Choice D rationale Drainage (exudate), particularly purulent drainage, is a principal sign of a local infection at the site (e.g., cellulitis or insertion site infection), not phlebitis alone. While phlebitis is an inflammatory process, infection involves microbial proliferation, leading to the formation of pus, which is not universally present in simple mechanical or chemical phlebitis.