An 87-year-old patient recovering from abdominal surgery has a continuous intravenous infusion to supply nutrients and antibiotics. What complication should you suspect when signs and symptoms of redness, warmth, and pain at the infusion site are reported?

A. Thrombosis involves formation of a blood clot inside the vein and may cause swelling, but redness, warmth, and pain at the insertion site are more indicative of inflammation rather than clot formation alone. B. Speed shock occurs when IV medications are administered too rapidly and causes systemic symptoms such as dizziness, hypotension, or cardiac irregularities, not localized redness or warmth. C. Hematoma is a localized collection of blood outside the vessel, typically causing bruising and swelling rather than redness, warmth, and pain along the vein. D. Phlebitis is inflammation of a vein, often caused by mechanical irritation from the catheter or chemical irritation from the IV solution or medications. Redness, warmth, and pain at the infusion site are classic signs of phlebitis.