Unexpected serum phosphorus lost in an amniotic fluid embolism patient

Serum phosphorus concentration reflects body energy equilibrium and functions of the kidney and the coagulation system. It is regulated by serum calcium concentration and parathyroid hormone (PTH).

We present a case of constant low concentrations of serum phosphorus in a 34-year-old female who was diagnosed with amniotic fluid embolism (AFE) and was continuously treated with extracorporeal membrane oxygenation (ECMO), continuous renal replacement therapy (CRRT) and blood component transfusion during an observational period of 11 days.

This case highlights that the release of inorganic phosphorus from platelets and plasma into the blood prompts PTH secretion. The administration of active vitamin D supplement and PTH antagonism should be considered to neutralize the negative regulatory effect of PTH on serum phosphorus and to benefit patients' recovery in the intensive care unit.