Hypercalcitoninemia and inappropriate calciuria in the acute trauma patient.

Purpose: This study was undertaken to determine the role of calcium-regulatory hormones (calcitonin [CT], parathyroid hormone [PTH], and vitamin D analogs) during the first 48 hours after acute trauma.

Methods: Eleven acutely traumatized patients admitted to the shock-trauma intensive care unit (STICU) in a tertiary care teaching hospital were enrolled. Eleven same-day elective surgery patients served as the control group. Levels of ionized calcium (Ca2+), total calcium, magnesium, phosphate, CT, PTH, vitamin D analogs, electrolyte supplementation, and renal electrolyte loss were recorded during the first 48 hours after admission to the STICU. Control-group measurements consisted of Ca2+ and CT.

Results: At admission, 91% of the patients had ionized hypocalcemia (1.04 +/- 0.10 mmol/L). Ca2+ levels increased significantly over time (1.13 +/- 0.08 at 24 hours; 1.16 +/- 0.07 at 48 hours) but remained below the control-group value (1.28 +/- 0.05; P < .05) despite supplementation. Ninety-one percent of the patients had increased CT values at admission, 91% at 24 hours, and 78% at 48 hours. Median CT values in the trauma patients were higher throughout the study than in the control group (P < .05). Urinary calcium loss in the trauma patients was within the normal range. PTH and vitamin D analog values were within the normal range throughout the study. Multiple regression analysis did not show any significant correlation between electrolytes and hormone or protein concentrations.

Conclusions: Acute trauma patients have ionized hypocalcemia associated with inappropriate urinary calcium loss, increased CT levels, and normal PTH and vitamin D analog values. We believe the degree of calciuria we observed was inappropriate in the context of ionized hypocalcemia. The cause of these increased CT levels is unclear. Our results suggest that Ca(2+)-regulatory mechanisms may be disrupted in the acute trauma patient.