From the Guidelines
Thyroid storm is a life-threatening medical emergency characterized by extreme symptoms of hyperthyroidism, including fever, tachycardia, altered mental status, vomiting, diarrhea, and cardiac arrhythmia, as diagnosed and treated based on a combination of signs and symptoms 1. The symptoms of a thyroid storm (thyrotoxic crisis) can be severe and include:
- Fever
- Tachycardia out of proportion to the fever
- Altered mental status, such as nervousness, restlessness, confusion, or seizures
- Vomiting and diarrhea
- Cardiac arrhythmia These symptoms can be triggered by an inciting event, such as surgery, infection, labor, or delivery, and can lead to shock, stupor, and coma if left untreated 1.
Diagnosis and Treatment
Diagnosis is based on a combination of signs and symptoms, as well as serum-free triiodothyronine (FT3), FT4, and TSH levels, although treatment should not be delayed for test results 1. Treatment should be initiated promptly with a standard series of drugs, including propylthiouracil or methimazole, saturated solution of potassium iodide or sodium iodide, dexamethasone, and phenobarbital, in addition to general supportive measures such as oxygen, antipyretics, and monitoring 1. It is essential to identify and treat the underlying cause of the thyroid storm, and to evaluate fetal status in pregnant women, depending on gestational age, with ultrasound examination, nonstress testing, or a biophysical profile 1.
From the Research
Symptoms of Thyroid Storm
The symptoms of thyroid storm, also known as thyrotoxic crisis, include:
- Hyperpyrexia (high fever) 2, 3, 4, 5
- Tachycardia (rapid heart rate) 3, 4, 5
- Hypotension (low blood pressure) 2
- Cardiac arrhythmias, including ventricular tachycardia 2, 6
- Altered mental status 6, 5
- Striking alterations in consciousness 5
- Death 2, 4
Mortality Rate
The mortality rate for thyroid storm is high, ranging from 10-30% 2, 6, 4, with some studies suggesting it can be as high as 75% if treatment is delayed 4.
Diagnosis and Treatment
Diagnosis of thyroid storm is made entirely on clinical findings, with no difference in thyroid hormone levels between patients with "uncomplicated" thyrotoxicosis and those undergoing a thyroid storm 4. Treatment includes:
- Supportive intensive care 2, 3
- Initiation of thionamides, beta blockers, corticosteroids, and anti-arrhythmics as necessary 2, 3
- Therapeutic plasma exchange (TPE) in some cases 6
- Blocking synthesis of thyroid hormones with antithyroid drugs, blocking release of preformed hormone with iodine, and correction of precipitating cause of storm 5