Thyrotoxic crisis (storm) - Thyroid axis

Thyrotoxic crisis (storm)

Definition

A rare syndrome of severe acute thyrotoxicosis, which may be life-threatening.

Aetiology

Surgery or radioactive iodine therapy in a patient with inadequately controlled thyrotoxicosis may precipitate a thyrotoxic storm. Other causes include severe illness or accident, uncontrolled diabetes, acute infection, severe drug reaction or myocardial infarction.

Pathophysiology

Levels of thyroid-binding protein in the serum fall and catecholamines are released. This results in increased free T3 and T4, coupled to increased sensitivity of the heart and nerves due to the presence of catecholamines.

Clinical features

The symptoms include life-threatening coma, heart failure and cardiogenic shock. There is a high fever (38– 41â—¦ C), flushing and sweating, tachycardia, often with atrial fibrillation and heart failure. Central nervous symptoms include agitation, restlessness, delirium and coma. Nausea, vomiting, diarrhoea and jaundice occur.

Management

Concomitant use of propranolol, potassium iodide, antithyroid drugs and corticosteroids.

Prognosis

Mortality of 10%.