Graves' disease is an autoimmune disorder that induces increase in thyroid hormone production and release. Although euthyroid
should be desirable to ensure a safe operation, some patients still undergo thyroidectomy with hyperthyroidism. The aim
of this study was to evaluate our preoperative strategies in patients with Graves' disease. A total of 186 patients underwent thyroidectomy for Graves' disease between 2003 and 2017. We gave all of these patients potassium iodide (KI) in order to
decrease their thyroid hormone levels. We compared the clinical factors among three groups defined by the value of serum
free triiodothyronine (FT3) after the administration of KI: (1) the good control group (n=126) with ≤6.0 pg/mL, (2) the fair control group (n=35) with >6.0 but ≤10.0 pg/mL, and (3) the poor control group (n=25) with >10.0 pg/mL. KI decreased the serum
levels of thyroid hormone. However, some patients still had hyperthyroidism, and the subsequent administration of corticosteroid
reduced FT3 but not thyroxine. Regarding the intraoperative course, the heart rate at 1 h after beginning general anesthesia
was higher in the poor control group than in the good control group (p<0.05), and the proportion of patients given
adrenergic beta-blocker was higher in the poor control group than in the other groups (p<0.01 each). One patient in the fair
control group experienced suspected thyroid storm after total thyroidectomy. The occurrence rate of other deteriorations was
identical among the three groups. With preparative KI and corticosteroid administration, almost all patients with Graves' disease were able to undergo thyroidectomy safely
