Verhaert N, Vander Poorten V, Delaere P, Bex M, Debruyne F
Department of Otorhinolaryngology, Head and Neck Surgery, University Hospitals Leuven, Leuven, Belgium.
B-ENT. 2006;2(3):129-33.
New entities, such as 'subclinical' over- and undersubstitution, are easily diagnosed after thyroid surgery due to improved testing methods, and the incidence of thyroidectomy with lifelong hormone substitution is increasing. Thus, there is a need to review conventional replacement therapy after thyroid surgery. We investigated the adequacy of our thyroid hormone replacement therapy for three months after total-, subtotal-, and hemithyroidectomy using an upper reference limit of thyrotropin (TSH) of 4.6 mU/L.
Eighty-seven patients undergoing thyroidectomy for benign thyroid pathology participated. Levothyroxine (L-T4) treatment began five days after surgery. Preoperatively euthyroid patients received 150 microg L-T4 daily following total thyroidectomy, 100 microg L-T4 after subtotal thyroidectomy, and 50 microg L-T4 after hemithyroidectomy. Preoperatively hyperthyroid patients received 100 microg L-T4 following total thyroidectomy and 50 microg L-T4 following subtotal thyroidectomy. An average of six weeks after surgery, thyrotropin (TSH) was measured (reference limits 0.15-4.60 mU/L), and necessary dose adjustments were made.
Of the patients who were preoperatively euthyroid, 45% with total thyroidectomy, 42% with subtotal thyroidectomy, and 17% with hemithyroidectomy required L-T4 dose adjustments. Of the patients who were preoperatively hyperthyroid, 60% of those with total thyroidectomy and all of those with subtotal thyroidectomy required L-T4 dose adjustments.
To avoid over- and undersubstitution after thyroidectomy, an optimal replacement therapy dose is necessary. A small majority of our preoperatively euthyroid patients received adequate therapy. Endocrinological follow-up six weeks after surgery revealed the need for L-T4 dose adjustments, especially in preoperatively hyperthyroid patients. When the extent of resection was similar for hyperthyroid and euthyroid patients, the same initial dose of L-T4 was justified.
由于检测方法的改进，甲状腺手术后诸如“亚临床”替代过量和替代不足等新情况易于诊断，且需终身激素替代治疗的甲状腺切除术发生率正在上升。因此，有必要对甲状腺手术后的传统替代疗法进行回顾。我们使用促甲状腺激素（TSH）的上限参考值4.6 mU/L，研究了全甲状腺切除术、次全甲状腺切除术和半甲状腺切除术后三个月甲状腺激素替代治疗的充分性。
87例因良性甲状腺疾病接受甲状腺切除术的患者参与研究。左甲状腺素（L-T4）治疗于术后五天开始。术前甲状腺功能正常的患者在全甲状腺切除术后每日接受150微克L-T4，次全甲状腺切除术后接受100微克L-T4，半甲状腺切除术后接受50微克L-T4。术前甲状腺功能亢进的患者在全甲状腺切除术后接受100微克L-T4，次全甲状腺切除术后接受50微克L-T4。术后平均六周时，测量促甲状腺激素（TSH）（参考值范围0.15 - 4.60 mU/L），并进行必要的剂量调整。
术前甲状腺功能正常的患者中，全甲状腺切除术患者有45%、次全甲状腺切除术患者有42%、半甲状腺切除术患者有17%需要调整L-T4剂量。术前甲状腺功能亢进的患者中，全甲状腺切除术患者有60%以及次全甲状腺切除术患者全部需要调整L-T4剂量。
为避免甲状腺切除术后替代过量和替代不足，需要最佳替代治疗剂量。我们术前甲状腺功能正常的患者中少数人接受了充分治疗。术后六周的内分泌随访显示需要调整L-T4剂量，尤其是术前甲状腺功能亢进的患者。当甲状腺功能亢进和甲状腺功能正常患者的切除范围相似时，相同的初始L-T4剂量是合理的。
