Thyroid Storm
Severe thyrotoxicosis - manifested by organ failure.
Manifestations
Thyroid storm is a very rare diagnosis - consider in the following presentations at least!
- (1) Patient with known hyperthyroidism plus any acute illness/deterioration.
- (2) New-onset atrial fibrillation and/or dilated cardiomyopathy.
- (3) New-onset delirium/psychosis plus abnormal vital signs (fever, tachycardia).
- (4) Hyperthermia (temperature above ~40C).
- (5) Septic-appearing patient without any focus of infection (i.e. distributive shock of unknown origin).
Thyroid storm usually presents as a mimic of another alternative diagnosis.
- Cardiac: tachycardia, arrhythmia, high output failure, pulmonary edema, hypertension
- Neurologic: delirium, agitation, psychosis, stupor, coma
- Hyperthermia (>40-41 degrees C with diaphoresis)
- GI: N/V/D, abdominal pain, jaundice or liver failure
Triggers of Thyroid Storm
- Infection
- Surgery or trauma
- Pulmonary embolism, MI, stroke
- Pregnancy related conditions
- DKA, hypoglycemia
- Thyroid-related precipitants
Diagnosis and Investigations
The diagnosis is a clinical diagnosis in the presence of proven hyperthyroidism.
- Thyroid labs:
- Thyroid labs aren't necessarily worse than uncomplicated hyperthyroidism. The differentiation between hyperthyroidism and thyroid storm is based on clinical findings – not how severe the lab abnormality is.
- TSH will be very low or undetectable
- Elevated free T4, T3 is excessively elevated as well
- Other possible labs:
- Hyperglycemia
- WBC abnormalities
- LFT abnormalities
- DIC
- The Burch-Wartofsky scale is used as a clinical measure of the likelihood of thyroid storm in a patient with known hyperthyroidism.
- 45 or more: Highly suggestive of thyroid storm.
- 25-44: Supports diagnosis of thyroid storm or impending storm.
- <25: Thyroid storm unlikely.