What is the immediate management of thyroid storm?

Immediate Management of Thyroid Storm

Thyroid storm requires immediate multi-drug therapy without waiting for laboratory confirmation, as treatment delays significantly increase mortality—start propylthiouracil (or methimazole), potassium iodide (1-2 hours after thionamides), beta-blockers, and corticosteroids simultaneously with supportive care. 1, 2

Initial Stabilization and Assessment

• Administer supplemental oxygen immediately and position the patient head-up to optimize respiratory function 2
• Hospitalize all patients, with severe cases requiring ICU admission for continuous monitoring 1, 2
• Do not delay treatment while awaiting thyroid function tests—mortality may rise to 75% with treatment delays, and thyroid hormone levels do not distinguish thyroid storm from uncomplicated thyrotoxicosis 2, 3

Multi-Drug Treatment Algorithm (Start All Simultaneously)

Step 1: Block Thyroid Hormone Synthesis (Start First)

• Propylthiouracil (PTU) is the preferred first-line agent because it inhibits both thyroid hormone synthesis AND peripheral conversion of T4 to T3, unlike methimazole which only blocks synthesis 1, 4, 5
• PTU dosing: 200-250 mg orally every 4-6 hours (loading dose 500-1000 mg may be used) 1
• Alternative: Methimazole 20-25 mg orally every 4-6 hours if PTU is unavailable or contraindicated 1
• If oral route unavailable: Consider rectal administration via enema or suppository formulations, though this is rarely needed 6

Step 2: Block Thyroid Hormone Release (Give 1-2 Hours AFTER Thionamides)

• Critical timing: Administer saturated solution of potassium iodide (SSKI) or sodium iodide only after starting thionamides—giving iodine first can paradoxically worsen thyrotoxicosis by providing substrate for more hormone synthesis 1, 4, 2
• SSKI dosing: 5 drops (250 mg) orally every 6 hours 1
• Alternative: Sodium iodide 500-1000 mg IV over 24 hours 1

Step 3: Control Adrenergic Symptoms with Beta-Blockers

• Propranolol is preferred because it blocks peripheral T4 to T3 conversion in addition to controlling cardiovascular symptoms 1
• Propranolol dosing: 60-80 mg orally every 4-6 hours, or 1-2 mg IV every 10-15 minutes until heart rate controlled 1
• For hemodynamically unstable patients: Use esmolol due to its ultra-short half-life allowing rapid titration—loading dose 500 mcg/kg IV over 1 minute, then maintenance infusion starting at 50 mcg/kg/min, titrating up to maximum 300 mcg/kg/min 1
• Monitor continuously for hypotension, bradycardia, and heart failure during beta-blocker administration 1
• Caution: Beta-blockers may mask signs of hypoglycemia and should be used carefully in patients with bronchospastic disease or severe heart failure 7

Step 4: Reduce Peripheral T4 to T3 Conversion

• Dexamethasone 2 mg IV/PO every 6 hours (or hydrocortisone 100 mg IV every 8 hours) to block peripheral conversion and treat potential relative adrenal insufficiency 1, 4, 2

Supportive Care Measures

• Aggressive cooling with antipyretics (acetaminophen preferred—avoid aspirin as it may increase free thyroid hormone levels) 1
• Fluid resuscitation for dehydration and hemodynamic support 1
• Identify and treat precipitating factors: infection, surgery, trauma, diabetic ketoacidosis, myocardial infarction, pulmonary embolism 1, 2
• Nutritional support as patients are hypermetabolic 8

Critical Monitoring Parameters

• Continuous cardiac monitoring with serial vital signs every 5-15 minutes during initial stabilization 1
• Watch for agranulocytosis with thionamide use—obtain baseline and serial complete blood counts 1, 2
• Monitor for hepatotoxicity, particularly with PTU (check liver function tests) 1, 6
• Assess for cardiac complications including heart failure, arrhythmias, and myocardial ischemia 1, 2
• Expect clinical improvement within 12-24 hours—if no improvement, consider escalation to plasmapheresis or emergent thyroidectomy 9, 3

Special Clinical Scenarios

Pregnancy

• Use the same aggressive treatment protocol—maternal mortality risk outweighs fetal concerns 1, 4
• PTU is preferred over methimazole in first trimester due to lower teratogenicity risk 1
• Monitor fetal status but avoid delivery during active storm unless absolutely necessary, as delivery can precipitate or worsen the crisis 1, 4

Patients on Vasopressor Support

• Esmolol is the beta-blocker of choice when patients require concurrent noradrenaline, due to its rapid reversibility if cardiovascular collapse occurs 1
• Alternative: Diltiazem 15-20 mg (0.25 mg/kg) IV over 2 minutes if beta-blockers absolutely contraindicated 1

Refractory Cases

• Therapeutic plasma exchange (TPE) removes circulating T3, T4, autoantibodies, and cytokines—consider for patients who fail medical therapy or cannot tolerate thionamides 9
• Emergent thyroidectomy should be considered if medical treatment fails to produce clinical improvement within 24 hours, as mortality approaches 75% without intervention 3, 10

Common Pitfalls to Avoid

• Never give iodine before thionamides—this is the most critical sequencing error and will worsen thyrotoxicosis 1, 4, 2
• Do not withdraw beta-blockers abruptly once started, as this may precipitate rebound tachycardia and worsening thyroid storm 7
• Do not delay treatment for laboratory confirmation—thyroid storm is a clinical diagnosis and treatment delay increases mortality 2, 3
• Monitor for transition to hypothyroidism after resolution, which commonly occurs and may require levothyroxine replacement 1, 2

Follow-Up After Acute Crisis

• Monitor thyroid function every 2-3 weeks after initial stabilization 1, 2
• Switch from PTU to methimazole for long-term maintenance after storm resolution due to PTU's cumulative hepatotoxicity risk with prolonged use 1
• Plan definitive therapy (radioactive iodine ablation or thyroidectomy) once patient is stable and euthyroid 2