Thyroid storm (TS) is a life-threatening emergency endocrine condition. Thyroid hormones should be normalized before thyroidectomy is performed in patients with Graves' disease. However, thyroid hormone levels are inevitably high in patients undergoing surgery. This study analyzed differences in vital sign changes during thyroidectomy between patients with controlled and uncontrolled Graves' disease and assessed thyroid hormone cutoffs for TS. Preoperative levels of the thyroid hormones free T4 (FT4), T3, and thyroid stimulating hormone (TSH) were retrospectively analyzed in patients who underwent total thyroidectomy for Graves' disease. Patients were divided into those with uncontrolled Graves' (UG) disease, defined as preoperative TSH <0.3 µIU/mL and FT4 >1.7 ng/dL, those with controlled Graves' (CG) disease, those with extremely uncontrolled Graves' (EUG) disease, defined as TSH <0.3 µIU/mL and FT4 >3.4 ng/dL, and finally, those without EUG (non-EUG). The 29 patients with Graves' disease included 12 with CG group and 17 with UG. FT4 and T3 concentrations were significantly higher in the UG group. There were no differences in vital sign and anesthetic agent. These 29 patients could also be divided into those with (n = 4) and without EUG (n = 25). The mean age was lower (21.5 vs. 40.9 years, p < 0.001) and the mean operation time was shorter (121.4 vs. 208.8 min, p = 0.003) in the EUG group. Requirements for anesthetic agents were greater in the EUG group. Mean FT4 concentration in the EUG group was 3.8 ng/dL, and there were no changes in vital signs during surgery. Vital sign change during thyroid surgery was not observed in patients with uncontrolled Graves' disease up to the twice upper normal limit of T4 level.
Keywords: Graves’ disease; thyroid storm; thyroidectomy; uncontrolled Graves’ disease; vital sign change.