Paradox of Phosphate in Rhabdomyolysis

Severe hypophosphatemia cause depletion of ATP and consequently cause rhabdomyolysis and inability of muscle cells to maintain membrane integrity. However, a paradoxical consequence occurs; with muscle breakdown in rhabdomyolysis, the damaged cells release phosphate into the extracellular space, masking the laboratory level or even clinical effects of hypophosphatemia. Plasma levels of hypophosphatemia will be misleading during the peak CPK level of rhabdomyolysis and should be repeated once rhabdomyolysis starts to resolve.

Reference:

Knochel JP. Hypophosphatemia and rhabdomyolysis. Am J Med. 1992 May. 92(5):455-7