What is the immediate management for 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), followed 1-2 hours later by potassium iodide, plus beta-blockers and corticosteroids simultaneously. 1, 2

Critical First Steps (Do Not Delay)

• Hospitalize immediately, with ICU admission for severe cases, as mortality can reach 75% without prompt treatment 2, 3
• Do not wait for thyroid function tests to initiate therapy—thyroid hormone levels do not distinguish thyroid storm from uncomplicated thyrotoxicosis 2, 3
• Provide supplemental oxygen and position patient head-up to optimize respiratory function 2

Step 1: Block Thyroid Hormone Synthesis (Start First)

• Administer propylthiouracil (PTU) as first-line agent because it uniquely inhibits both thyroid hormone synthesis AND peripheral conversion of T4 to T3 1, 4
• If PTU unavailable or contraindicated (hepatotoxicity), use methimazole as alternative 1
• PTU is preferred over methimazole specifically in thyroid storm due to its dual mechanism of action 1, 4

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

• Administer saturated potassium iodide solution or sodium iodide 1-2 hours AFTER starting thionamides 1, 2
• Critical pitfall: Never give iodine before thionamides—this can paradoxically worsen thyrotoxicosis by providing substrate for additional hormone synthesis 1, 2

Step 3: Control Cardiovascular Symptoms

Hemodynamically Stable Patients

• Propranolol 60-80 mg orally every 4-6 hours is first-line for stable patients, as it blocks peripheral T4 to T3 conversion in addition to controlling adrenergic symptoms 1

Hemodynamically Unstable Patients (on vasopressors)

• Esmolol is the beta-blocker of choice due to ultra-short half-life allowing rapid titration 1
• 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 as needed 1
• Monitor continuously with serial blood pressure and heart rate every 5-15 minutes during titration 1

When Beta-Blockers Contraindicated

• Use diltiazem 15-20 mg (0.25 mg/kg) IV over 2 minutes, then 5-15 mg/h maintenance infusion 1

Step 4: Reduce Peripheral T4 to T3 Conversion

• Administer dexamethasone or another corticosteroid to block peripheral conversion and treat potential relative adrenal insufficiency 1, 2

Step 5: Supportive Care

• Administer antipyretics for fever control (avoid aspirin as it may increase free thyroid hormone) 1
• Aggressive hydration and supportive care 1
• Identify and treat precipitating factors (infection, surgery, trauma, medication non-adherence) 1, 2

Monitoring Requirements

• Continuous cardiac monitoring in ICU setting 1
• Watch for agranulocytosis with thionamide use—a potentially life-threatening complication 1, 2
• Monitor for cardiac complications including heart failure 1, 2
• Serial thyroid function testing every 2-3 weeks after stabilization 1, 2
• Watch for transition to hypothyroidism, which commonly occurs after thyroid storm treatment and may require levothyroxine initiation 1, 2

Refractory Cases

• Consider therapeutic plasma exchange (TPE) if conventional therapy fails or patient cannot tolerate thionamides 5, 6
• TPE removes T3, T4, autoantibodies, and catecholamines; typically performed daily for 4 days with 1.0 plasma volume exchange 5
• Early thyroidectomy should be considered if medical treatment fails to produce clinical improvement within 12-24 hours 3

Special Populations

Pregnancy

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

Patients Unable to Take Oral Medications

• Consider rectal administration of propylthiouracil via enema if oral route unavailable 7
• Intravenous methimazole available in Europe and Japan but not in United States 7

Expected Timeline

• Clinical improvement should occur within 12-24 hours of initiating therapy 3
• If no improvement by 24 hours, escalate to TPE or surgical intervention 3