PIV315: Complications with Vascular Access Devices – Part 1

1. Infiltration: Definition and Grading

Infiltration occurs when a non-vesicant intravenous solution leaks out of the vein and into the surrounding subcutaneous tissue, typically because the catheter tip has moved out of the lumen, punctured the vessel wall, or become dislodged. It is the most common peripheral IV complication. The hallmark findings are swelling, taut and cool skin, blanching, a slowed or stopped infusion, and often a dull ache; blood return may be sluggish or absent. Because the leaking fluid is not tissue-destructive, most infiltration resolves without lasting harm once the catheter is removed and supportive care is provided, but large-volume infiltration can still cause pressure injury and, rarely, compartment syndrome.

Consistent grading is what turns a subjective impression into an actionable finding. The INS classifies infiltration into grades that escalate from a barely perceptible change to frank tissue breakdown, and each grade carries a defined clinical response. Grading the finding, documenting it, and comparing it against the previous assessment lets the team see whether a site is stable or deteriorating.