Treatment of Thyroid Storm
Thyroid storm requires immediate treatment with a combination of propylthiouracil or methimazole, potassium iodide, beta-blockers, corticosteroids, and supportive care to prevent mortality. 1
First-Line Treatment Algorithm
Step 1: Block Thyroid Hormone Synthesis
- Administer propylthiouracil (PTU) as first choice since it both inhibits thyroid hormone synthesis and peripheral conversion of T4 to T3 1, 2
- Alternatively, methimazole can be used if PTU is unavailable 1
- Do not delay treatment while waiting for laboratory confirmation 1
Step 2: Block Thyroid Hormone Release (1-2 hours after thionamides)
- Administer saturated potassium iodide solution or sodium iodide 3, 1
- Critical timing: Never administer iodine before thionamides as this can worsen thyrotoxicosis 1
Step 3: Control Adrenergic Effects
- Beta-blockers (propranolol or esmolol) are essential for controlling tachycardia and other cardiovascular symptoms 3, 4
- For hemodynamically unstable patients, consider short-acting beta-blockers like esmolol 3
- Non-dihydropyridine calcium channel blockers are alternatives if beta-blockers are contraindicated 1
Step 4: Reduce Peripheral Conversion of T4 to T3
- Administer dexamethasone or another corticosteroid 3, 1
- This helps reduce peripheral conversion of T4 to T3 and treats possible relative adrenal insufficiency 1
Supportive Care
- Provide oxygen therapy as needed 1
- Administer antipyretics to control fever 1
- Identify and treat precipitating factors (infection, surgery, childbirth, etc.) 1, 5
- Consider intensive care unit admission for close monitoring 3
Special Considerations
Alternative Administration Routes
- When oral administration is not possible, consider rectal thionamide administration via enema or suppository 6
- Intravenous methimazole is available in Europe and Japan but not in the United States 6
Pregnancy
- Treatment protocol is similar to non-pregnant patients 1
- Monitor fetal status and avoid delivery during thyroid storm unless absolutely necessary 1
- Be aware that thyroid storm can occur during cesarean section in undiagnosed hyperthyroidism 5
Refractory Cases
- Consider plasmapheresis or thyroidectomy in cases not responding to medical therapy 6, 7
- Early thyroidectomy should be considered if medical treatment fails to result in clinical improvement within 12-24 hours 7
Monitoring and Complications
Monitoring
- Expect clinical improvement within 12-24 hours with appropriate treatment 7
- Monitor thyroid function every 2-3 weeks after initial stabilization 3
- Watch for transition to hypothyroidism, which is common after thyroid storm treatment 3
Potential Complications
- Monitor for agranulocytosis with thionamide use 1
- Watch for hepatocellular injury with PTU 6
- Be vigilant for cardiac complications such as heart failure 1, 7
- Overall mortality is 10-20% but may rise to 75% if treatment is delayed 7