Hypophosphatemia--incidence, etiology, and prevention in the trauma patient

Hypophosphatemia is associated with a number of undesirable physiologic consequences and has been reported to occur frequently in trauma patients. We studied patients in the immediate posttraumatic period to document a) the decrease in serum P, b) renal P excretion, and c) the response to prophylactic PO4 administration. In both group 1 (n = 12) and group 2 (n = 10) patients, we measured serum P, creatinine, ionized Ca, urinary P excretion, and creatinine clearance daily for the first 3 to 4 days postinjury. Patients in group 2 also received 0.5 mmol/kg.day of PO4 for the first 48 h after admission. Group 1 patients exhibited a significant (p less than .05) decrease in serum P over the first 24 h (1.00 +/- 0.30 to 0.75 +/- 0.23 mmol/L). In contrast, group 2 patients did not demonstrate a decrease in serum P. Urinary P excretion in group 1 accounts for the observed decrease in serum P. The results of our study show that the immediate posttraumatic period is associated with a decrease in serum P and massive urinary P excretion. We also showed that prophylactic administration of 0.5 mmol PO4/kg.day prevents serum P decrease.