[Erythrocyte calcium and pH levels during postoperative tetany following radical operations for thyroid cancer].

To investigate the mechanism of postoperative tetany, erythrocyte calcium and pH were consecutively measured in 15 patients who underwent total removal and subsequent autotransplantation of parathyroid glands at the surgery for thyroid cancer. Of these, 8 patients presented tetany signs, but the other 7 patients had no symptoms. In the non-tetanized group, the concentration of erythrocyte calcium decreased by 33.2% and 46.0% on the 3rd and 5th postoperative day, respectively. On the other hand, it increased by 49.8% and 34.6%, respectively, in the tetanized group, showing a significantly different concentration between two groups. No significant differences were observed, however, in the serum calcium level at any time between two groups. The erythrocyte pH as well as the plasma pH in the tetanized group was significantly higher on the 3rd postoperative day, than that in the non-tetanized group. These results suggest the possibility that the elevated cellular calcium content is more closely linked with postoperative tetany than the serum calcium level, and that the elevated cellular pH as well as plasma pH is another causative factor in evoking tetany.