Purpose: This study was undertaken to determine the role of calcium re
gulatory hormones (calcitonin [CT], parathyroid hormone [PTH], and vit
amin D analogs) during the first 48 hours after acute trauma. Methods:
Eleven acutely traumatized patients admitted to the shock-trauma inte
nsive care unit (STICU) in a tertiary care teaching hospital were enro
lled. Eleven same-day elective surgery patients served as the control
group. Levels of ionized calcium (Ca2+), total calcium, magnesium, pho
sphate, CT, PTH, vitamin D analogs, electrolyte supplementation, and r
enal electrolyte loss were recorded during the first 48 hours after ad
mission to the STICU. Control-group measurements consisted of Ca2+ and
CT. Results: At admission, 91% of the patients had ionized hypocalcem
ia (1.04 +/- 0.10 mmol/L). Ca2+ levels increased significantly over ti
me (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 supple
mentation. Ninety-one percent of the patients had increased CT values
at admission, 91% at 24 hours, and 78% at 48 hours. Median CT values i
n the trauma patients were higher throughout the study than in the con
trol group (P < .05). Urinary calcium loss in the trauma patients was
within the normal range. PTH and vitamin D analog values were within t
he 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 io
nized hypocalcemia associated with inappropriate urinary calcium loss,
increased CT levels, and normal PTH and vitamin D analog values. We b
elieve the degree of calciuria we observed was inappropriate in the co
ntext of ionized hypocalcemia. The cause of these increased CT levels
is unclear. Our results suggest that Ca2+-regulatory mechanisms may be
disrupted in the acute trauma patient. Copyright (C) 1996 by W.B. Sau
nders Company.