Serum and other calcium fractions in patients after severe musculoskeletal trauma.

Alterations in serum calcium fractions after trauma may be of clinical importance. For investigation of this problem, serum calcium fractions were studied prospectively in 42 patients with severe musculoskeletal injuries. The severity of trauma was assessed with the Apache II severity of disease classification system. Serum ionized calcium, total calcium, pH, albumin, and arterial blood gases were measured daily for the first five days after admission. The fat embolism syndrome developed in eight patients; they were more severely injured than the others, and they had significantly lower levels of serum ionized calcium for all five days of the study. There was a strong negative correlation between the Apache II score and serum ionized calcium. Ionized hypocalcemia has a strong association with development of the complications of severe musculoskeletal trauma, such as the fat embolism syndrome.