A 67-year-old lady presents to the Emergency Department anxious, confused and agitated. She has also vomited several times. She has recently been started on a course of amoxicillin for a presumed chest infection by her GP. You are unable to take a coherent history from her, but she has her regular medications with her, which include aspirin, simvastatin and carbimazole. She has a friend with her who states she stopped taking her medications a few days ago. Her observation are: temperature 38.9°C, HR 138, RR 23, BP 173/96, SaO2 97% on air.

1. What is the most likely diagnosis?

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This patient is suffering from a thyrotoxic crisis (Thyroid storm).

Thyroid storm is a relatively rare diagnosis, occurring in 1-2% of patients with established hyperthyroidism. It is an important diagnosis not to miss, however, because of the high mortality rate associated with it (approximately 10%).

Thyrotoxic crisis classically occurs in patients with underlying Graves’ disease or toxic multinodular goitre. Often, there is sudden onset of severe hyperthyroidism with:

  • Hyperpyrexia (over 41°C), dehydration.
  • Heart rate greater than 140 beats per minute (with or without atrial fibrillation or other arrhythmias), hypotension, atrial dysrhythmias, congestive heart failure.
  • Nausea, jaundice, vomiting, diarrhoea, abdominal pain.
  • Confusion, agitation, delirium, psychosis, seizures or coma.

2. What has precipitated this condition in this case?

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In this case it would appear that the sudden discontinuation of her carbimazole has precipitated her condition.

Thyroid storm is often precipitated by a physiological stressor, such as:

  • Premature or inappropriate cessation of anti-thyroid therapy
  • Recent surgery or radio-iodine treatment
  • Intercurrent infection (especially chest infections)
  • Trauma
  • Diabetic ketoacidosis or hyperosmolar diabetic crisis
  • Thyroid hormone overdose
  • Pre-eclampsia

3. What investigations should be performed?

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Blood tests that should be organized include:

  • Full blood count
  • Urea and electrolytes
  • Blood glucose or bedside BM
  • Coagulation screen
  • CRP
  • Thyroid profile (T4/T3 and TSH)
  • Bone profile / calcium (10% of patients develop hypocalcaemia)
  • Blood cultures


Other important investigations that should be organized include:

  • Urine dipstick / MC&S
  • Chest X-ray
  • ECG

4. How should this patient should be managed?

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The management of thyroid storm should include the following:

  • Commence IV fluids e.g. 1-2 litres 0.9% saline
  • Support and manage airway as appropriate
  • Pass nasogastric tube (as patient is vomiting)
  • Refer urgently for inpatient management
  • Paracetamol 1 g PO/IV for pyrexia
  • Benzodiazepines for sedation e.g. diazepam 5-20 mg PO/IV
  • Steroids for co-existing adrenal suppression e.g. hydrocortisone 100 mg IV
  • Antibiotics if intercurrent infection present
  • Beta-blockers e.g. propranolol 80 mg PO
  • High dose carbimazole 45-60 mg/day
  • Potassium iodide 200 mg IV over 1 hour (blocks release of thyroid hormones)


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