Early postoperative levothyroxine initiation after total thyroidectomy for Graves' disease

Area of Science:

• Endocrinology
• Surgical Oncology
• Pharmacology

Background:

• Lack of evidence-based standards for initiating levothyroxine (LT4) replacement therapy after total thyroidectomy in hyperthyroid Graves' disease.
• Current practice at some institutions initiates LT4 on postoperative day 1, but clinical validity requires examination.
• Understanding perioperative thyroid hormone kinetics is crucial for optimizing postoperative management.

Purpose of the Study:

• To investigate perioperative thyroid hormone kinetics in patients undergoing total thyroidectomy.
• To assess the safety and efficacy of early (postoperative day 1) LT4 initiation in hyperthyroid Graves' disease.
• To provide data supporting potential future guidelines for LT4 therapy timing.

Main Methods:

• Prospective study including 30 patients with Graves' disease (18 hyperthyroid, 12 euthyroid) and 12 with thyroid nodules undergoing total thyroidectomy.
• Serial blood sampling for thyroid hormone (FT3, FT4) measurement preoperatively (D-1) and postoperatively (D0, D1, D3, W3, M3).
• Levothyroxine (LT4) initiated on postoperative day 1 for all patients requiring replacement.

Main Results:

• In hyperthyroid Graves' disease patients, serum FT3 significantly decreased immediately post-surgery, normalizing by D1 but declining again by D3 and remaining low at W3 and M3 despite D1 LT4 initiation.
• Serum FT4 levels showed a slower decline but remained within the normal range through M3.
• Patients with euthyroid Graves' disease and thyroid nodules maintained hormone levels within or near the reference range throughout the study period.

Conclusions:

• Initiating levothyroxine (LT4) on postoperative day 1 is a safe and effective strategy for maintaining thyroid function in patients with hyperthyroid Graves' disease post-total thyroidectomy.
• The study findings support early postoperative LT4 initiation and may inform the development of future clinical guidelines.
• Monitoring thyroid hormone levels is essential, as FT3 may remain suppressed despite early LT4 therapy in this population.