Which of the following best defines infiltration?

• A. An accumulation of fluid in the tissue surrounding an IV needle site
• B. A collection of blood in tissue around a wound
• C. Leakage of IV fluid into the surrounding air
• D. A plug preventing IV flow

Answer: (A)

Infiltration is the accumulation of IV fluids in the tissue around the IV catheter site, rather than inside the vein. This causes swelling at the needle site and can make the IV flow slow or stop. It happens when the catheter isn’t properly inside the vein or the vein is damaged, so the IV solution leaks into surrounding tissue.

This is best defined by the description of fluid escaping into the tissue around the site, not by a collection of blood in tissue (that would be a hematoma), not by air entering tissue (which would be an air-related complication), and not by a plug or blockage that prevents flow. When you see swelling around the IV site with leakage of IV solution into the surrounding tissue, infiltration is the appropriate diagnosis. If it occurs, stop the infusion, remove and redeploy at a new site, apply appropriate care, and monitor for any signs of tissue damage.