Overview
A thyrotoxic crisis is a potentially life-threatening complication of hyperthyroidism. It can lead to hyperthermia, cardiac arrhythmias heat failure, multiple organ failure, and sepsis.
To help make sense of this chapter, it may be helpful to refer to Endocrine and Metabolic Physiology.
Epidemiology
- Incidence is 0.2 per 100,000
Causes
- Infection
- Trauma or surgery
- Withdrawal/non-compliance with antithyroid medication
- Myocardial infraction or stroke
- Pulmonary embolism
- Childbirth
- Overdose of levothyroxine
- Diabetic ketoacidosis, hyperosmolar hyperglycaemic state
- Hypoglycaemia
Presentation
Patients generally present with sudden-onset severe hyperthyroidism:
- Hyperpyrexia (>41.0ºC)
- Tachycardia >140 bpm
- Arrhythmias (e.g. atrial fibrillation)
- Nausea
- Diarrhoea
- Confusion
- Psychosis
- Seizures
- Coma
Investigations
- TFTs:
- Elevated T3 and T4
- Reduced TSH
- ECG
- Chest x-ray
- ABGs
Management
All patients
- 1st-line: beta-blockers, propylthiouracil, and hydrocortisone
- High levels of thyroid hormone can increase the breakdown of cortisol, increasing the risk of adrenal insufficiency. Hydrocortisone is given to mitigate this risk
Prognosis
- The risk of death can be as high as 90% if left untreated
