Rapid intravenous infusion of potassium phosphate may result in which complication?

• A. Hypercalcemia
• B. Metabolic alkalosis
• C. Vitamin D deficiency
• D. Thrombophlebitis

Answer: (D)

Rapid IV administration of potassium phosphate can irritate the veins. The phosphate salt, especially when given quickly, is hyperosmolar and caustic to the vascular endothelium, causing inflammation and thrombus formation in the vein—thrombophlebitis. Clinically, you’d see vein redness, warmth, tenderness, and possibly a localized lump along the infusion site.

The other options don’t fit this acute IV complication pattern: hypercalcemia isn’t typically caused by phosphate infusion (phosphate can lower calcium, potentially causing hypocalcemia); vitamin D deficiency is not an immediate IV-related issue; metabolic alkalosis isn’t a common direct result of rapid phosphate infusion.