Hypophosphatemia in acute-phase response syndrome patients. Preliminary data

Hypophosphatemia is common in acutely ill patients and possibly may occur in the acute-phase response syndrome (APR), secondary to hyperglycemia and shifts of extracellular phosphorus into cells.

To compare the frequency of hypophosphatemia in patients with or without APR.

All plasma phosphorus results (n = 822) corresponding to a 6-month period were searched using an university hospital mainframe. Relevant laboratory and clinical details were also registered. All cases of alcohol withdrawal, diabetic ketoacidosis, parenteral nutrition, and chronic respiratory alkalosis and patients receiving antacids or intravenous dextrose (5%) in water at a rate higher than 50 g glucose/day were excluded. APR was defined on the basis of severe trauma or infection and at least two of the following: fever, leukopenia (WBC <5,000/mm3), or leukocytosis (WBC >9,000/mm3). Hypophosphatemia was defined as a serum phosphorus concentration <2.0 mg/dl.

A total of 227 patients were studied. Thirty-five (15.4%) patients fulfilled the criteria for APR. Hypophosphatemia was observed in 11.4% of the APR-positive patients, in contrast to 0.5% in the APR-negative group. Hyperglycemia was more common in APR-positive patients (60.0 vs. 36. 8%).

Our results suggest that hypophosphatemia may be attributed to increased serum glucose levels secondary to tissue injury and infection in APR-positive patients.