Difference between revisions of "Hypophosphatemia"

(Differential Diagnosis)
(Differential Diagnosis)
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==Differential Diagnosis==
 
==Differential Diagnosis==
 +
===Causes of Hypophosphatemia===
 
*Internal redistribution
 
*Internal redistribution
 
**Refeeding of malnourished
 
**Refeeding of malnourished
Line 16: Line 17:
 
**[[Nonketotic hyperglycemia]]
 
**[[Nonketotic hyperglycemia]]
 
**Receiving hyperalimentation
 
**Receiving hyperalimentation
**Acute respiratory alkalosis
+
**Acute [[respiratory alkalosis]]
 
**Hungry bone syndrome  
 
**Hungry bone syndrome  
 
*Decreased intestinal absorption
 
*Decreased intestinal absorption
 
**Inadequate intake  
 
**Inadequate intake  
 
**Antacids containing aluminum or magnesium  
 
**Antacids containing aluminum or magnesium  
**Steatorrhea and/or chronic diarrhea  
+
**Steatorrhea and/or chronic [[diarrhea]]
 
*Increased urinary excretion
 
*Increased urinary excretion
 
**Vitamin D deficiency or resistance
 
**Vitamin D deficiency or resistance
 
**Primary renal phosphate wasting (rare genetic disorders)  
 
**Primary renal phosphate wasting (rare genetic disorders)  
**Fanconi syndrome  
+
**[[Fanconi syndrome]]
***Multiple myeloma  
+
***[[Multiple myeloma]]
 
**Osmotic diuresis (most often due to glucosuria)
 
**Osmotic diuresis (most often due to glucosuria)
**Proximally acting diuretics (e.g. acetazolamide and some thiazide diuretics)
+
**Proximally acting diuretics (e.g. [[acetazolamide]] and some [[thiazide diuretics]])
 
**Acute volume expansion
 
**Acute volume expansion
 
**Intravenous iron administration  
 
**Intravenous iron administration  

Revision as of 13:29, 26 August 2015

Background

Clinical Features

Differential Diagnosis

Causes of Hypophosphatemia

  • Internal redistribution
  • Decreased intestinal absorption
    • Inadequate intake
    • Antacids containing aluminum or magnesium
    • Steatorrhea and/or chronic diarrhea
  • Increased urinary excretion
  • 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