Consult Rounds: Hyperphosphatemia

In the steady state, the serum phosphate concentration is primarily determined by the ability of the kidneys to excrete dietary phosphate.  When you give an acute phosphate load  over several hours, transient hyperphosphatemia can ensue.

There are three general circumstances in which this occurs: massive acute phosphate load; chronic renal failure; and a primary increase in proximal phosphate reabsorption. The fourth is pseudohyperphosphatemia.




1. CAUSES OF Phosphate Load to consider:
Tumor lysis syndrome
Rhabdomyolysis
Lactic acidosis
Ketoacidosis
Phosphate Enemas or laxatives
Vitamin D Toxicity

2. RENAL FAILURE is self explanatory

3. Increased Tubular Reabsorption of Phosphate:
    Hypoparathyroidism
    FGF-23 Deficiency
    Acromegaly
    Bisphosphanates
    Tumoral Calcinosis

4. Pseudohyperphosphatemia from elevated bilirubin, paraproteins, lipids and hemolysis

Hope this simplifies the differential of hyperphosphatemia