Burch-Wartofsky >= 45; fever, tachycardia, delirium; 4 Ps: Propranolol, PTU, Potassium iodide, Prednisone/Hydrocortisone.
Severe hypothermia, bradycardia, hypoventilation, altered mental status; IV levothyroxine + hydrocortisone.
Refractory shock, hyponatremia, hyperkalemia, hypoglycemia; emergent IV hydrocortisone 100 mg q8h.
Calcium > 14 mg/dL; stones, bones, groans, psychiatric overtones; vigorous IV saline + calcitonin + bisphosphonate.
Thyroid Storm vs. Myxedema Coma: Pathophysiology & Presentation
Thyroid emergencies represent life-threatening decompensations of hyperthyroidism or hypothyroidism triggered by acute physiological stressors (infection, trauma, noncompliance, surgery).
| Feature | Thyroid Storm | Myxedema Coma |
|---|---|---|
| Body Temperature | Hyperthermia (often > 104°F / 40°C) | Severe hypothermia (< 95°F / 35°C) |
| Cardiovascular | Sinus tachycardia, atrial fibrillation, high-output failure | Sinus bradycardia, hypotension, pericardial effusion |
| Neuropsychiatric | Extreme agitation, psychosis, delirium, seizures | Lethargy, stupor, coma ('myxedema madness') |
| Precipitating Factors | Infection, iodinated contrast, surgery, DKA | Cold exposure, sedatives, infection, stroke |
The Stepwise 4-P Protocol for Thyroid Storm
Treatment must be initiated immediately upon clinical suspicion without waiting for laboratory confirmation:
- Propranolol (Beta-Blocker): High-dose IV/oral propranolol controls adrenergic symptoms and uniquely blocks peripheral conversion of T4 to T3.
- PTU (Propylthiouracil): Preferred over methimazole in storm because it blocks de novo thyroid hormone synthesis and peripheral T4 to T3 conversion.
- Potassium Iodide (Lugol solution or SSKI): Administer at least 1 hour after PTU to prevent the Wolff-Chaikoff effect from becoming substrate for new hormone synthesis (Jod-Basedow phenomenon).
- Prednisone / Hydrocortisone (Steroids): IV hydrocortisone treats potential relative adrenal insufficiency and inhibits peripheral T4 to T3 conversion.
Acute Adrenal Insufficiency & Adrenal Crisis
Adrenal crisis occurs when cortisol production fails to meet metabolic demand. Primary adrenal insufficiency (Addison disease) presents with hyperkalemia, hyponatremia, and hyperpigmentation (elevated ACTH/MSH). Secondary/tertiary adrenal insufficiency (abrupt steroid withdrawal) exhibits normal potassium (aldosterone preserved by RAAS).
Diagnostic workup: Serum cortisol and ACTH, followed by high-dose Cosyntropin (synthetic ACTH) stimulation test. In an unstable patient, do not delay treatment: administer IV hydrocortisone 100 mg stat; dexamethasone may be used if testing must be preserved as it does not cross-react in the cortisol assay.
- Thyroid Autonomics: Sympathetics originate from T1-T4, ascending through the cervical sympathetic ganglia (superior, middle, inferior). Treatment of upper thoracic spine and rib raising balances sympathetic hyperactivity.
- Adrenal Gland Autonomics: T10-T11 via the thoracic splanchnic nerves and celiac/aorticorenal ganglia.
- Adrenal Chapman Reflex Point: Anterior point: 2 inches superior and 1 inch lateral to the umbilicus. Posterior point: intertransverse space between T11 and T12.
- Never give iodine before thionamides (PTU/methimazole) in thyroid storm — administering iodine first provides raw fuel for catastrophic hormone surge.
- Never administer etomidate during rapid sequence intubation (RSI) in septic shock or suspected adrenal crisis; etomidate transiently inhibits 11-beta-hydroxylase and induces adrenal insufficiency.
- In myxedema coma, always administer empiric stress-dose corticosteroids alongside IV thyroid hormone to prevent precipitating fatal adrenal crisis in patients with concurrent secondary adrenal failure.