K-Phos

Q: 21 years old female with Anorexia Nervosa is admitted to the ICU with severe electrolyte imbalance. The patient has been prescribed "K-Phos-Rider". What is the usual ratio of Phosphate: Potassium in combo intravenous (IV) administration?

Answer: 1:1.46 

If both are deficient, potassium and phosphate are usually administered in a combo IV infusion.

1 mmol of intravenous phosphate delivers 1.46 meq of potassium in "K-phos rider". 

Usually, 7.5 mmol of phosphate with 10 meq of potassium is administered. It should be infused over a period of an hour.

#electrolytes

References/further reading:

1. Perreault MM, Ostrop NJ, Tierney MG. Efficacy and safety of intravenous phosphate replacement in critically ill patients. Ann Pharmacother. 1997 Jun;31(6):683-8. doi: 10.1177/106002809703100603. PMID: 9184705.

2. Hemstreet BA, Stolpman N, Badesch DB, May SK, McCollum M. Potassium and phosphorus repletion in hospitalized patients: implications for clinical practice and the potential use of healthcare information technology to improve prescribing and patient safety. Curr Med Res Opin. 2006 Dec;22(12):2449-55. doi: 10.1185/030079906X148463. PMID: 17257459.

3. Charron T, Bernard F, Skrobik Y, Simoneau N, Gagnon N, Leblanc M. Intravenous phosphate in the intensive care unit: more aggressive repletion regimens for moderate and severe hypophosphatemia. Intensive Care Med. 2003 Aug;29(8):1273-8. doi: 10.1007/s00134-003-1872-2. Epub 2003 Jul 5. PMID: 12845429.