Which of the following is a key sign of infiltration?

Swelling at the IV site is a key sign of infiltration because it indicates that the intravenous fluids or medications intended for delivery into the vein are leaking into the surrounding tissue instead of remaining within the bloodstream. This occurs when the IV catheter is not positioned correctly, which can happen due to various reasons such as vessel movement or a breach in the vein wall.

The local swelling manifests as an increased volume of interstitial fluid, leading to noticeable changes at the site. Patients may also experience discomfort or pain in the area, but the primary indicator remains the swelling. Recognizing infiltration promptly is crucial in order to minimize tissue damage and complications, which reinforces the importance of monitoring the IV site during therapy effectively.

In contrast, increased heart rate, high blood pressure, and pale skin covering the body can be related to various other physiological responses that do not specifically indicate infiltration at the IV site. Therefore, these symptoms are not considered definitive indicators of infiltration compared to localized swelling.