Predictability of hypocalcemia using early postoperative serum calcium levels

Objective. In operations involving the thyroid or parathyroid glands, posto perative serum calcium levels are one contributing factor to patients lengt h of hospital stay. In this study, we wanted to determine whether early pos toperative serum calcium levels could be used to predict hypocalcemia follo wing operations of the thyroid or parathyroid glands. Methods: A retrospective chart review was performed on 203 patients who had undergone operations involving risk, to the parathyroid glands. This inclu ded patients who had bilateral thyroid operations or those who had one or m ore parathyroid glands removed for various disease processes. Postoperative calcium levels were plotted as a function of time, and the slope between t he first two levels was examined. Both serum calcium levels were drawn with in 12 hours after the operation. Results. A positive slope predicted normocalcemia in 100% of patients under going thyroid or parathyroid procedures. A negative slope was predictive in magnitude. Patients who developed hypocalcemia had an average slope two to three times more negative than those remaining normocalcemic. Conclusions. It appears that early serum calcium levels may be predictive f or postoperative hypocalcemia in operations that put the parathyroid glands at risk.