What is the treatment for a thyroid storm?

Thyroid Storm Treatment

Thyroid storm is a medical emergency requiring immediate multi-drug therapy without waiting for laboratory confirmation: administer propylthiouracil (or methimazole), followed 1-2 hours later by potassium iodide, plus beta-blockers, corticosteroids, and aggressive supportive care. 1, 2, 3

Immediate Stabilization and Hospitalization

• Do not delay treatment while awaiting laboratory confirmation, as mortality rises significantly with treatment delays and can reach 75% without prompt intervention 1, 4
• Hospitalize all patients, with severe cases requiring ICU admission 1, 2
• Provide supplemental oxygen and position the patient head-up to improve respiratory function 1
• Administer antipyretics to control fever (avoid aspirin as it may displace thyroid hormone from binding proteins) 2, 3

Multi-Drug Treatment Algorithm

Step 1: Block New Thyroid Hormone Synthesis (Give First)

• Propylthiouracil (PTU) is the preferred first-line agent because it both inhibits thyroid hormone synthesis AND blocks peripheral conversion of T4 to T3 1, 2, 5
• Methimazole is an acceptable alternative if PTU is unavailable, though it lacks the peripheral conversion blocking effect 1, 3
• PTU is readily absorbed and approximately 35% is excreted in urine within 24 hours 5

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

• Administer saturated solution of potassium iodide (SSKI) or sodium iodide only after thionamides have been started 1, 2, 3
• Critical pitfall: Never give iodine before thionamides, as this can paradoxically worsen thyrotoxicosis by providing substrate for new hormone synthesis 1, 3
• Wait at least 1-2 hours after starting PTU or methimazole before administering iodine 2

Step 3: Control Adrenergic Symptoms with Beta-Blockers

• Propranolol is the most widely studied and preferred beta-blocker because it blocks peripheral T4 to T3 conversion in addition to controlling cardiovascular symptoms 2, 6
• Typical dosing: 60-80 mg orally every 4-6 hours (adjust based on heart rate and blood pressure) 2
• For hemodynamically unstable patients requiring vasopressor support, use esmolol due to its ultra-short half-life allowing rapid titration 2
  • Esmolol 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 2
  • Monitor continuously with serial blood pressure and heart rate every 5-15 minutes during titration 2
• If beta-blockers are contraindicated (severe heart failure, bronchospasm), use non-dihydropyridine calcium channel blockers like diltiazem: 15-20 mg (0.25 mg/kg) IV over 2 minutes, then 5-15 mg/h maintenance infusion 2, 3

Step 4: Reduce Peripheral T4 to T3 Conversion

• Administer dexamethasone or another corticosteroid to reduce peripheral conversion of T4 to T3 and treat potential relative adrenal insufficiency 1, 2, 3
• Corticosteroids provide dual benefit in thyroid storm management 1, 3

Critical Monitoring Requirements

• Monitor for agranulocytosis with thionamide use (PTU and methimazole can cause this life-threatening complication) 1, 3
• Watch for cardiac complications including heart failure, arrhythmias, and hemodynamic instability 1, 3
• Increase frequency of observations for patients with suspected thyroid storm 1
• 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 replacement 1, 2

Supportive Care and Precipitating Factor Management

• Identify and aggressively treat precipitating factors: infection, surgery, trauma, labor/delivery, diabetic ketoacidosis, or medication non-compliance 3, 7, 8
• Provide aggressive hydration and electrolyte replacement 3
• Treat hyperthermia with cooling measures and antipyretics 2, 3
• Monitor for and manage gastrointestinal symptoms (nausea, vomiting, diarrhea) 8

Special Considerations in Pregnancy

• Treatment protocol is identical to non-pregnant patients 1, 2, 3
• Monitor fetal status closely throughout treatment 1, 2, 3
• Avoid delivery during active thyroid storm unless absolutely necessary, as this can worsen the crisis 1, 2, 3
• Thyroid storm affects less than 1% of pregnant women with hyperthyroidism but remains a medical emergency 9

Important Clinical Pitfalls to Avoid

• Never wait for laboratory confirmation before starting treatment - thyroid hormone levels do not distinguish thyroid storm from uncomplicated thyrotoxicosis 1, 8, 4
• Never give iodine before thionamides - this worsens thyrotoxicosis by providing substrate for hormone synthesis 1, 3
• Never abruptly withdraw beta-blockers in hyperthyroid patients, as this may precipitate exacerbation of symptoms including thyroid storm 6
• Be aware that severely ill patients may not have the highest thyroid hormone levels - free T3 and FT3/FT4 ratio may inversely correlate with disease severity 1

Definitive Treatment After Crisis Resolution

• Plan definitive treatment of underlying thyrotoxicosis after acute crisis is controlled 1, 3
• Options include continued medical therapy, thyroidectomy, or radioactive iodine ablation 1, 3
• Early thyroidectomy should be considered if medical treatment fails to produce clinical improvement within 12-24 hours 4
• Adjust beta-blocker doses when patient becomes euthyroid due to increased clearance during hyperthyroidism 1