[Transient hypocalcemia after thyroidectomy]

In a patient submitted to thyroidectomy a transitory hypocalcemia can develop, the frequency of which is very variable in reference with on international literature. Several hypotheses have been enunciated to explain the phenomenon. This study would contribute to suggest its etiology and to quantify its entity. For this purpose we selected a series of patients among those operated from September, 1989 to May, 1991. 6 of them were affected by non toxic multinodular goiter (group 1), while 12 were affected by Graves' disease (group 2). We evaluated their serum levels of calcium, parathormone (iPTH), calcitonin (CT), osteocalcin and total proteins. In both groups we registered a temporary hypocalcemia that resulted statistically significant. In group 1 the hypocalcemia was associated with a decrease in iPTH levels, so that the cause of hypocalcemia in patients submitted to thyroidectomy for nontoxic multinodular goiter seems to be a transient parathyroid failure, while in group 2 the hypocalcemia was associated with a decrease in total protein levels, showing a different pathogenetic mechanism. We conclude that the transitory hypocalcemia post-thyroidectomy relies on a different etiology in the two thyropathies.