What is the management for thyroid storm?

Management of Thyroid Storm

Thyroid storm requires immediate multi-drug therapy without waiting for laboratory confirmation, combining propylthiouracil (or methimazole), potassium iodide administered 1-2 hours after thionamides, beta-blockers, corticosteroids, and aggressive supportive care to prevent mortality rates that can reach 75% with treatment delays. 1, 2, 3

Immediate Stabilization and Hospitalization

• All patients with thyroid storm require hospitalization, with severe cases mandating ICU admission 1, 2
• Administer supplemental oxygen immediately and position the patient head-up to improve respiratory function 2
• Do not delay treatment while awaiting laboratory confirmation, as mortality rises significantly with any delay 2, 3
• Increase frequency of vital sign monitoring and continuous cardiac monitoring 2

Step 1: Block Thyroid Hormone Synthesis (First Medication)

Propylthiouracil (PTU) is the preferred first-line thionamide because it inhibits both thyroid hormone synthesis AND peripheral conversion of T4 to T3, unlike methimazole which only blocks synthesis 1, 4, 5

• Administer PTU as the initial medication in the treatment sequence 1, 4
• Alternative: Use methimazole only if PTU is unavailable 1
• Critical monitoring: Watch for agranulocytosis with thionamide use 1, 2
• PTU may cause hepatocellular injury requiring transition to methimazole 6
• If oral access is impossible (e.g., NPO status, intubation), rectal administration via enema or suppository is an alternative, though intravenous methimazole is available in Europe and Japan 6

Step 2: Block Thyroid Hormone Release (Second Medication - Timing Critical)

Administer saturated potassium iodide solution or sodium iodide 1-2 hours AFTER starting thionamides—never before, as this can worsen thyrotoxicosis by providing substrate for additional hormone synthesis 1, 4, 2

• This timing is crucial to prevent exacerbation of the crisis 1, 4

Step 3: Control Adrenergic Symptoms with Beta-Blockers

Propranolol is the preferred beta-blocker because it provides dual benefit: controlling cardiovascular symptoms AND blocking peripheral T4 to T3 conversion 1

• Typical dosing: 60-80 mg orally every 4-6 hours 1
• In hemodynamically unstable patients requiring vasopressor support (e.g., noradrenaline), use esmolol instead due to its ultra-short half-life allowing rapid titration 1
  • Esmolol loading dose: 500 mcg/kg (0.5 mg/kg) IV over 1 minute 1
  • Maintenance infusion: Start at 50 mcg/kg/min, titrate up to maximum 300 mcg/kg/min 1
  • Monitor continuously with serial blood pressure and heart rate every 5-15 minutes during titration 1
• Alternative if beta-blockers contraindicated: Diltiazem 15-20 mg (0.25 mg/kg) IV over 2 minutes, then 5-15 mg/h maintenance 1
• Caution: Beta-blockers may precipitate cardiovascular collapse in patients with severe heart failure or bronchospastic disease 7
• Important: Abrupt withdrawal of propranolol may precipitate worsening thyroid storm 7

Step 4: Reduce Peripheral T4 to T3 Conversion

Administer dexamethasone or another corticosteroid to reduce peripheral conversion of T4 to T3 and treat possible relative adrenal insufficiency 1, 4, 2

• This provides dual benefit for hormone conversion blockade and adrenal support 1, 4

Supportive Care Measures

• Control hyperthermia with antipyretics (avoid aspirin as it may increase free thyroid hormone levels) 1
• Provide aggressive hydration 1
• Identify and treat precipitating factors aggressively: infection, surgery, trauma, childbirth, medication non-adherence 1, 2
• Monitor for cardiac complications, particularly heart failure and arrhythmias 1, 2

Special Populations

Pregnancy

• Treatment protocol is identical to non-pregnant patients 1, 4, 2
• Monitor fetal status continuously 1, 4, 2
• Avoid delivery during active thyroid storm unless absolutely necessary 1, 4, 2

Patients on Immune Checkpoint Inhibitors

• For severe symptoms (Grade 3-4): Hold immune checkpoint inhibitors until symptoms resolve 1
• Obtain endocrine consultation for all severe cases 1

Critical Monitoring Parameters

• Monitor thyroid function every 2-3 weeks after initial stabilization 1, 2
• Watch for transition to hypothyroidism, which commonly occurs after thyroid storm treatment and may require levothyroxine initiation 1, 2
• Monitor for agranulocytosis with thionamide use (complete blood count) 1, 4, 2
• Adjust beta-blocker doses when patient becomes euthyroid due to increased drug clearance during hyperthyroidism 2
• Monitor for hypotension, bradycardia, and hyperkalemia when using beta-blockers, especially with renal impairment 1

Refractory Cases

• Consider plasmapheresis for extreme cases not responding to medical therapy 6, 8, 9
• Early thyroidectomy should be considered if medical treatment fails to produce clinical improvement within 12-24 hours 3
• Alternative agents for specific situations: cholestyramine, lithium carbonate, or potassium perchlorate 8, 9

Expected Clinical Response

• Clinical improvement should occur within 12-24 hours of initiating treatment 3
• If death occurs, it is most commonly from cardiopulmonary failure, particularly in elderly patients 3
• Overall mortality with appropriate treatment is 10-20%, but can reach 75% with delayed therapy 3