UMEM Educational Pearls

Category: Critical Care

Title: "K-Phos"

Keywords: phosphate, hypotension, hypomagnesemia (PubMed Search)

Posted: 3/18/2008 by Mike Winters, MD (Updated: 12/7/2019)
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Potassium Phosphate ("K-phos")

Over the weekend, I had a patient with Dr. Scott that had a phosphate of 0.8 mmol/L.  Phosphate < 1.0 mmol/L is an indication for IV repletion.  IV repletion involves giving potassium phosphate.  An important clinical question, therefore, is how much potassium does the patient actually get?

  • 1 mmol of IV phosphate delivers 1.46 mEq of potassium
  • Recommended infusion rate is 5 mmol/hr
  • Rapid infusion may lead to severe hypocalcemia, hypotension, acute renal failure, hypomagnesemia, and hypernatremia