Endocrine Abstracts

A 52-year man came to Emergency Department with Atrial Fibrillation with rapid ventricular response due to amiodarone induced thyrotoxicosis (AIT). The patient was found tachi-arrhythmic (153 beats per minute), tachypnoic (27 breaths per minute) and with intense hyperidrosis. His first blood test documented thyroid stimulating hormone (TSH) <0.01 mUI/l, free triiodothyronine (fT3) 20.0 pmol/l and free thyroxine (fT4) over 100 pmol/l. Thyroid ultrasonography revealed an enlarged hypoechoic and non-homogeneous thyroid gland, in absence of vascular signal. He was initially treated with esmolol 60 mg ev, hydration and hydrocortisone 100 mg ev. Subsequently we began therapy with prednisone 50 mg/die, methimazole 20 mg/die, propranolol 160 mg/die and digitalis 0.0625 mg/die. This first therapy did not improve his clinical condition, thus we substitute methimazole with Propylthiouracil 200 mg/die, prednisone with desametasone 8 mg/die and added potassium iodure 400 mg/die. Nevertheless, blood tests and heart rate still did not improve. We proposed therapeutic plasma exchange (TPE), whom he underwent in the next two following days, as a bridge therapy for surgery. After two runs of TPE with markedly improvement of biohumoral status, the patient underwent urgent thyroidectomy with slowly normalization of TSH and reduction of FT3 and FT4 during the post-surgery days. The man was eventually dismissed by the hospital with desametasone, propranolol, digitalis, oral anticoagulant and calcium carbonate, then introducing replacement therapy with Levothyroxine in the following days. Amiodarone is a drug frequently used in different kinds of arrhythmias. It can induce thyrotoxicosis up to 6-10 % of the patients. There are two types of AIT: AIT1 (iodine-induced in patients with underlying thyroid autonomy) treated by thyrostatic drugs and AIT2 (destructive thyroiditis, results of direct damage or apoptosis in thyrocytes) treated by corticosteroids. Thyroid storm is a rare but potentially fatal endocrinology emergency, with a mortality of 10-30 % due to cardiovascular and multisystemic involvement. AIT can be a cause of thyroid storm. Burch-Wartofsky Point Scale helps physician to determinate the gravity of the condition: a value ≥45 requires aggressive therapy. TPE can be used as bridge therapy to thyroidectomy in patients refractory or with contraindications to medical management of thyroid storm. TPE aims to reduce FT3 and FT4, autoantibodies and cytokines and the activity of 5’-monodeiodinasis. Those effects are usually temporary, leading to the risk of rebound-thyrotoxicosis. TPE may be considered also in other pathological endocrinological conditions, such as corticosteroid responsive encephalopathy associated with autoimmune thyroiditis.