Thyroid Storm

OVERVIEW

• life threatening exacerbation of hyperthyroid state with 1 or more organ dysfunction
• clinical diagnosis, very elevated thyroid markers not enough

ETIOLOGY

Hyperthyroidism due to:

• Graves Disease – most common
• Toxic Nodule or Toxic Multinodular Goitre
• Thyroiditis (infective or auto-immune)

Triggers for thyroid storm:

• Surgery (thyroid and non-thyroid) –> can occur 6 – 24 hours post op
• Discontinuation of anti-thyroid medication
• Trauma
• Burns
• Hyperemesis Gravidarum
• Parturition
• Acute illness
  • Infective
  • Non-infective: DKA, MI, CVA, TBI
• Iodine Use (iodinated contrast or radioiodine therapy)
• Medication Reactions (amiodarone, anaesthetics, salicylates)

CLINICAL FEATURES

General

• Fever
• Diaphoresis

Cardiovascular

• Tachycardia (sinus tachycardia is most common)/Tachyarrhythmia (AF with RVR most common tachyarrhythmia)
• Signs of cardiac failure (peripheral/pulmonary oedema)

Neurological

• CNS dysfunction of varying severity (agitation –> psychosis –> seizure –> coma)

Gastrointestinal

• diarrhoea/nausea/vomiting
• unexplained jaundice

DIAGNOSTIC SCORES

• Quantitative diagnostic scoring systems are used as adjunct to clinical assessment
  • e.g elderly patients may present with “apathetic” thyroitoxicosis with atypical symptoms
• May help differentiate uncomplicated thyrotoxicosis from thyroid storm

Burch-Wartofsky Point Scale (introduced in 1993)

• Use in adults with biochemical thyrotoxicosis

Figure 1. Reproduced from Kopp PA, Giordani I, Feldt-Rasmussen U, Forget-Renaud A. Approach to the patient with thyroid storm. J Clin Endocrinol Metab. 2026;111(5):1484–1494. doi:10.1210/clinem/dgag054. Licensed under CC BY 4.0.

Japanese Thyroid Association (JTA)/Japanese Endocrine Society (JES) Score

Figure 2. Reproduced from Kopp PA, Giordani I, Feldt-Rasmussen U, Forget-Renaud A. Approach to the patient with thyroid storm. J Clin Endocrinol Metab. 2026;111(5):1484–1494. doi:10.1210/clinem/dgag054. Licensed under CC BY 4.0.

MANAGEMENT

Supportive

• Disposition: ICU/HDU
• Temperature Management
  • Passive +/- active cooling measures
  • Antipyretic therapy: Paracetamol
    • NSAIDs and Aspirin contraindicated –> displace thyroid hormones from binding proteins and increase free thyroid hormone levels
• Fluid Management
  • IV fluids to replace losses from diaphoresis/GI losses
• Electrolyte Management
  • Hyponatremia/Hypomagnesemia/Hypo- or Hyperkalemia
    • Will need regular monitoring and intravenous replacement
• Blood Glucose Management
  • Close monitoring due to risk of hypoglycemia
  • Addition of IV dextrose

Treatment of Underlying Precipitant

Specific

• β-Blockade: Reduce peripheral sympathetic symptoms/manifestations
  • Propranolol
    • PO 60 – 80 mg PO q4hrly (can be upto 120 mg q4hrly)
    • IV 0.5 – 1 mg over 10 minutes, followed by 1 – 3 mg over 10 minutes (for more rapid control)
  • Esmolol
    • Loading dose: 250 – 500 mcg/kg in 1 min IV
    • Maintenance infusion: 50 – 200 mcg/kg/min IV
• Anti-thyroid Agents: Reduce thyroid hormone production and secretion
  • Propylthiouracil (PTU): (inhibits thyroid hormone synthesis by blocking thyroid peroxidase and also blocks peripheral conversion of T4 to T3)
    • Loading dose: 500 – 1000 mg (Routes: PO/NG or PR)
    • Daily: 800 – 1200 mg in divided doses (200 – 300 mg q4 – 6hrly)
    • Adverse Effects: Hepatotoxicity/allergic hepatitis, ANCA-associated vasculitis, agranulocytosis
  • Carbimazole: (pro-drug converted to methimazole post absorption which blocks thyroid peroxidase)
    • Dose: 20 mg q 6 – 8 hrly (Route: PO/NG)
    • Adverse Effects: Category D –> contraindicated in 1st trimester of pregnancy due to risk of congenital abnormalities
• Iodine: (Two-fold mechanism: 1. Wolff-Chaikoff Effect: autoregulatory response to an excess of iodine – resulting in acute inhibition of thyroid hormone synthesis by inhibiting both the oxidation of iodine and subsequent combination with tyrosine. 2. Plummer Effect: inhibition of thyroid hormone release in response to excess iodine.)
  • 5% Lugol’s Iodine Solution (Iodine 5% + Potassium Iodide 10% in water)
    • Dose: 0.5 mL (10 drops) q 6 – 8 hrly (each drop delivers ~ 6.25 mg iodine)
    • Administer at least 1 hour after giving antithyroid drugs – risk of increased substrate for thyroid hormone production if given before thionamides.
• Steroids (Reduce peripheral conversion of T4 to T3 + supplement for relative adrenal insufficiency)
  • Hydrocortisone (Preferred in thyroid storm due to both glucocorticoid + mineralocorticoid effect)
    • Loading dose: 300 mg IV
    • Dose: 100 mg IV q 8hrly
  • Dexamethasone (higher glucocorticoid potency, no mineralocorticoid effect)
    • Dose 4 – 8 mg BD (Route: PO or IV)
• Bile Acid Sequesterants
  • Cholestyramine (increased elimination of T4 by preventing reabsorption after biliary excretion)
    • Dose: 4 g q 8hrly PO

Adjunct

• Plasmapheresis (remove circulating thyroid hormones/cytokines)
  • Rescue for severe or refractory thyroid storm
  • Consider if no improvement with maximal medical therapy within 24 – 48 hours or if significant adverse effects from thionamides
• Anticoagulation
  • For patients with persistent AF depending on CHADS2VA score

References and Links

Journal articles

• Bello G, Ceaichisciuc I, Silva S, Antonelli M. The role of thyroid dysfunction in the critically ill: a review of the literature. Minerva Anestesiol. 2010 Nov;76(11):919-28. PMID: 20935602.
• Carroll R, Matfin G. Endocrine and metabolic emergencies: thyroid storm. Ther Adv Endocrinol Metab. 2010 Jun;1(3):139-45. PMC3475282.
• Kopp PA, Giordani I, Feldt-Rasmussen U, Forget-Renaud A. Approach to the patient with thyroid storm. J Clin Endocrinol Metab. 2026 May;111(5):1484-1494. PMID: 41655224
• Muller C, Perrin P, Faller B, Richter S, Chantrel F. Role of plasma exchange in the thyroid storm. Ther Apher Dial. 2011 Dec;15(6):522-31. PMID: 22107688.

FOAM and web resources

• ALIEM — Diagnosing hyperthyroidism: Answers to 7 common questions  (2013)
• ALIEM — Thyroid Storm: Treatment Strategies (2013)