[Occurrence of hypophosphatemia in a Danish hospital population]

Hypophosphataemia is a potentially dangerous condition which may be present but unrecognized in prolonged periods. The incidence of hypophosphataemia among patients in a Danish hospital population was determined retrospectively by registering the number of blood samples with low serum phosphate values (less than or equal to 0.6 mmol l/l) in a Danish university hospital during a period without and in a period with an open casualty department. Case reports from patients with low serum phosphate values were reviewed with the object of revealing the causes of the hypophosphataemia and possible symptoms which might be related to the hypophosphataemic condition. A total of 192 patients were found with serum phosphate values less than or equal to 0.6 mmol/l but only 15 patients with severe hypophosphataemia (serum phosphate less than or equal to 0.3 mmol/l). No relationship between the serum phosphate concentration and the symptoms could be demonstrated. The commonest causes of hypophosphataemia were gastrointestinal loss and parenteral infusion of fluids. Quoting of low serum phosphate measurement is not recommended unless this analysis has been specially requested as the majority of cases even of severe hypophosphataemia are self-limiting and do not produce symptoms.