- Primary hyperthyroidism is caused by the excess production of thyroid hormones from the thyroid glands.
- Secondary hyperthyroidism is caused by the excess production of thyroid-releasing hormones (Hypothalamus) or thyroid-stimulating hormones (Pituitary).
- Hyperthyroidism refers to excess circulating hormone resulting only from thyroid gland hyper function. Most commonly cause by Graves' Disease.
- Thyrotoxicosis refers to excess circulating thyroid hormone originating from any cause.
- Thyroid storm is an extreme manifestation of thyrotoxicosis. It presents as an acute life-threatening hypermetabolic state caused either by excessive release of thyroid hormones or due to altered peripheral response to thyroid hormone following a precipitating event.
- Graves' Disease
- Toxic Goitre
- Thyroiditis (Viral, Radiation)
- Secondary (Pituitary or Hypothalamus related)
- Thyrotoxicosis Factitia
- Drug Induced (Amiodarone, Interleukin 2)
- Metastatic (Struma Ovarii)
- Hydatidiform Mole
- Heat related Illness
- Recreational Drug Use
- Iodinated Contrasts
- Thyroxine Overdose
- Cardiac Monitor and IV accsess.
- Fluids, Maintenance of Electrolytes and Glucose. Cooling for hyperthermia.
- Add antibiotics as infection is a known precipitant and hard to distinguish in ED
- Consider Cholestyramine to decrease the reabsorption of thyroid hormone from the enterohepatic circulation. In thyrotoxicosis, there is increased enterohepatic circulation of thyroid hormone.
The peripheral conversion of thyroxine to triiodothyronine is blocked by propylthiouracil, propranolol, and glucocorticoid. Glucocorticoids are essential in treatment since blockade produced by propylthiouracil and propranolol is not significant. . Glucocorticoid also treat underlying relative adrenal insufficiency.
6. Find and treat the precipitation event (Sepsis, DKA, ACS)
7. Definitive Treatment - Radioactive Iodine or Surgery
Other potential considerations:
- Direct removal of thyroid hormone with plasma exchange
- Use of Potassium Perchlorate in Amiodarone induced thyrotoxicosis: Potassium perchlorate interferes with the production of new hormones
- Lithium: Used in cases of hypersensitivity to iodine. Lithium inhibits thyroid hormone release from thyroid gland. Typical dosing in thyroid storm is 300 milligrams every 8 hours. Monitor levels to avoid toxicity.
- Peripheral beta blockade: Reserpine or Guanethidine can be used, if there is a contraindication for BB use. These agents do not block beta receptors and interfere with catecholamine function (by depleting stores and blocking release)
- Consider Thyroid Strom in any patient presenting with fever, tachycardia and Altered Mental Status.
- PTU or Methimazole must be started first and Iodine therapy should be given at least 1 hour later.
- Manage with beta blockers, PTU/Methimazole, Steroids and Potassium iodide
- Identify and treat the precipitation cause