Hypophosphatemia

Revision as of 13:28, 26 August 2015 by Rossdonaldson1 (talk | contribs) (Differential Diagnosis)

Background

Clinical Features

Differential Diagnosis

  • Internal redistribution
  • Decreased intestinal absorption
    • Inadequate intake
    • Antacids containing aluminum or magnesium
    • Steatorrhea and/or chronic diarrhea
  • Increased urinary excretion
    • Vitamin D deficiency or resistance
    • Primary renal phosphate wasting (rare genetic disorders)
    • Fanconi syndrome
      • Multiple myeloma
    • Osmotic diuresis (most often due to glucosuria)
    • Proximally acting diuretics (e.g. acetazolamide and some thiazide diuretics)
    • Acute volume expansion
    • Intravenous iron administration
  • Renal replacement therapy

Diagnosis

  • 2.5-2.8 Mild
  • 1.0-2.5 Mod
  • <1.0 Severe

Treatment

  • Mild-mod
    • KPhos /neutra phos PO
  • Severe
    • KPhos 2.5-5 mg/kg IV over 6hr

Harbor UCLA Adult Treatment Guidelines

  • Serum phosphate 1 mg/dl to 2 mg/dl
    • Able to take PO
      • Minimize or eliminate all dextrose-containing IV solutions
      • Aggressively treat acidosis
      • 1 tab K-phos neutral 250mg Q hour x 5 doses
        • Each tab contains phosphorus 8 mmol, Na 13 mEq, K1.1 mEq
      • Recheck serum phosphate after last dose, and repeat dosing if continues to be <2 mg/dl
    • NOT able to take PO
      • Minimize or eliminate all dextrose-containing IV solutions
      • Aggressively treat acidosis
      • Give 15 mmol of IV potassium phosphate over 2.5 hours (contains 22 mEq K)
        • Peripheral administration may cause burning at injection site
        • Consider central venous administration, if available
        • Repeat dosing regimen if serum phosphate remains <2 mg/dl
  • Serum phosphate <1 mg/dl
    • Minimize or eliminate all dextrose-containing IV solutions
      • Exceptions: vasopressors, sedatives, analgesics, antibiotics, blood products, NS
    • Aggressively treat acidosis
    • Give 45 mmol of IV potassium phosphate over 7 hours (contains 66 mEq of K)
      • Peripheral administration may cause burning at injection site
      • Consider central venous administration, if available
    • If patient can tolerat PO, ALSO follow steps 1 above
    • Recheck serum phosphate after infusion
      • Repeat IV administration if <1 mg/dl
      • Consider oral administration if >1mg and <2 mg/dl

See Also