The Pathophysiology and Clinical Characteristics of Severe Hypophosphatemia

HypophosphataemiaPathophysiology, effects and management on the intensive care unit

“…The correlation between serum phosphate concentrations and symptoms is less than clear [14]. Hypophosphataemia does not necessarily indicate phosphorus depletion.…”

“…Hypophosphataemia is usually subdivided into two categories. Moderate hypophosphataemia is arbitrarily defined as 0.32-0.65 mmol.l À1 and severe hypophosphataemia as less than 0.32 mmol.l À1 [14]. The incidence of moderate hypophosphataemia in hospitalised patients has been reported to range from 2.5 to 3.1% [15] and the incidence of severe hypophosphataemia ranges from 0.24 to 0.42% [16].…”

“…A chronically malnourished patient is often in a catabolic state which is associated with muscle breakdown and the subsequent loss of intracellular phosphate. Serum phosphate remains relatively normal against a background of elevated urinary losses, leading to total body depletion [14]. Clearly, this loss cannot be predicted just by measuring serum phosphate.…”

“…A myopathy has been described that mainly affects the proximal muscles and which may be severe enough to produce immobility or pain on motion [14]. A more malignant myopathy associated with rhabdomyolysis and elevated serum creatine phosphokinase concentrations has also been described.…”

“…A more malignant myopathy associated with rhabdomyolysis and elevated serum creatine phosphokinase concentrations has also been described. However, the role of hypophosphataemia in patients with critical illness myopathy is questionable because patients have developed the disorder in spite of normal serum phosphate concentrations [14,16].…”