Surgery and anaesthesia for amiodarone-associated thyrotoxicosis

Total thyroidectomy for amiodarone-associated thyrotoxicosis: should surgery always be delayed for pre-operative medical preparation?

Objective:

Amiodarone can induce severe hyperthyroidism that justifies its withdrawal and the introduction of antithyroid drugs. Continuing amiodarone use, failure to control hyperthyroidism and poor clinical progress may require thyroidectomy. This study aimed to evaluate patients’ post-operative development and mid-term outcome after thyroidectomy for amiodarone-associated thyrotoxicosis.

Study design:

Prospective case series.

Setting:

Tertiary care centre.

Subjects and methods:

We prospectively collected cases of amiodarone-associated thyrotoxicosis requiring thyroidectomy due to failure of antithyroid treatment, despite amiodarone discontinuation. Post-thyroidectomy complications were compared immediately, 30 days and one year post-operatively, and also for scheduled versus emergency surgery cases.

Results:

Of 11 total cases, nine scheduled thyroidectomy cases had no morbidity after elective surgery. Two cases required emergency surgery for multiple organ failure and cardiac problems. Immediate post-operative complications (mostly haemodynamic) occurred in both cases (emergency vs routine surgery, p = 0.018).

Conclusion:

In such cases, pre-operative medical treatment is vital to limit peri- and post-operative complications, but surgery should not be delayed if the haemodynamic status deteriorates. Surgery, with careful anaesthesia, is the cornerstone of the treatment.

Rapid preparation of severe uncontrolled thyrotoxicosis due to Graves' disease with Iopanoic acid--a case report

PURPOSE

To report the rapid preoperative preparation of a case of thyrotoxicosis due to Graves' disease resistant to medical treatment.

CLINICAL FEATURES

A 14-yr-old boy presented with a history of progressive swelling in the neck. Signs and symptoms were compatible with hyperthyroidism. Thyroid function tests revealed: serum T4 296.5 nmol.L(-1), serum T3 6.06 nmol.L(-1) and serum thyroid-stimulating hormone < 0.15 mIU.L(-1). The diagnosis of thyrotoxicosis due to Graves' disease was made. Therapy was instituted with carbimazole 30 mg.day(-1) and propranolol 80 mg.day(-1), which were gradually increased to carbimazole 80 mg.day(-1) and propranolol 120 mg.day(-1), without response. Preparation was attempted by adding Iopanoic acid 500 mg four times a day and dexamethasone 0.5 mg four times a day in addition to the above drugs for five days. T3 levels declined to 1.8 nmol.L(-1), but the serum T4 remained elevated. Symptoms of hyperthyroidism persisted but with decreased intensity. As the patient could not be made euthyroid, surgery was planned to relieve the symptoms. Anesthesia was uneventful except for intraoperative and postoperative tachycardia, which was managed successfully with esmolol.

CONCLUSION

In life threatening thyrotoxicosis refractory to medical treatment, Iopanoic acid may be used as an adjuvant to antithyroid drugs for rapid preparation of the patient prior to surgery.

[Anaesthesia and amiodarone-associated hyperthyroidism]

Amiodarone can induce severe hyperthyroidism that justifies its withdrawal and initiation of antithyroid drugs. Impossibility to stop amiodarone, failure to control hyperthyroidism and unfavourable evolution can lead to thyroidectomy. Cardiac manifestations, persistence of hyperthyroidism and interactions between amiodarone and anaesthetic or haemodynamic drugs may contraindicate anaesthesia. We report nine consecutive cases of amiodarone-associated hyperthyroidism that prompted us to perform thyroidectomy under general anaesthesia. The features and anaesthetic data of patients were noted. The antithyroid medical treatment failed in all patients. After thyroidectomy, evolution was favourable in all nine cases, without any intra or postoperative complication, in spite of the extent of hyperthyroidism and the severity of the associated cardiac problems. Despite potential high risks, thyroidectomy for amiodarone-induced hyperthyroidism does not seem to increase morbidity or mortality and allows a quick return to euthyroidism and reintroduction of amiodarone.

Can amiodarone be restarted after amiodarone-induced thyrotoxicosis?

Thyrotoxicosis is a well-documented and studied complication of treatment with amiodarone, but little has been written about the risks and treatment of recurrent thyrotoxicosis upon re-exposure to amiodarone. One such case is outlined here and discussed by a panel of experts.