Thyroid storm

Thyroid storm refers to the life threatening acute presentation of thyroid hormone excess of any cause, typified by pyrexia, tachycardia, neurological disturbance, gastrointestinal upset and heart failure.

Free thyroxine and thyroid stimulating hormone  

Thyroid storm can only be diagnosed in the presence of severe biochemical thyrotoxicosis: a completely suppressed TSH with a thyroxine level typically over 45miU/L. 

 Urea and electrolytes

Renal function must be documented at presentation as dehydration often occurs with thyroid storm and can cause acute kidney injury.

Hyponatraemia and hyperkaleamia would increase suspicion for adrenocortical deficiency.

Full blood count

A septic screen should be performed in all patients presenting acutely unwell, with tachycardia and pyrexia.

Liver function test  

Liver function will often be abnormal with thyrotoxicosis.

It is part of the scoring system to diagnose storm, and should also be documented prior to the commencement of anti-thyroid drugs. 

Blood glucose  

Glucose levels should be monitored at presentation and four hourly during acute treatment.

Diabetic ketoacidosis is also a recognised trigger for thyroid storm.

Bone profile

Hypercalcaemia may associate severe thyrotoxicosis.

Blood and urine cultures

A trigger for thyroid storm should be sought in all cases.

A septic screen should also be performed in all patients presenting acutely unwell, with tachycardia and pyrexia.

Random cortisol

Thyroid storm is most commonly associated with autoimmune rather than nodular thyroid disease and treatment usually involves steroids. It may therefore be useful to send a random cortisol at presentation.

Electrocardiogram

ECG is mandatory in the acutely unwell patient with tachycardia and to confirm atrial fibrillation.

Chest radiograph  

Useful to confirm pulmonary oedema if cardiac failure is suspected.

A septic screen should also be performed in all patients presenting acutely unwell, with tachycardia and pyrexia which should include a chest radiograph. 

Chest radiograph  

Useful to confirm pulmonary oedema if cardiac failure is suspected.

A septic screen should also be performed in all patients presenting acutely unwell, with tachycardia and pyrexia which should include a chest radiograph. 

CT head

Often necessary to exclude other acute causes of confusion or altered GCS. 

Cardiac enzymes

Myocardial infarction is a recognised trigger for thyroid storm. Cardiac enzymes should be checked if clinical suspicion is high or with an abnormal ECG.