Hypophosphatemia.

Hypophosphatemia, defined as serum phosphate levels less than 2.5 mg%, is a relatively common disorder that can affect virtually every organ system. Phosphate deficiency can result from decreases in phosphate intake or absorption, increased loss from renal and nonrenal pathways, and transcellular phosphate shifts. Optimum therapy is directed at recognizing patients at greatest risk, correcting the underlying abnormality, and supplementing phosphate intake. Intravenous phosphate therapy is indicated for severe hypophosphatemia (serum phosphate less than 1 mg%) with close monitoring of serum phosphate, calcium, potassium, and magnesium levels. Indications for phosphate therapy and suggestions for empirical iv therapy in severe hypophosphatemia are presented.