What is the best first treatment for a patient suspected of having thyroid storm, in addition to supportive measures, presenting with tachycardia, hypertension, agitation, and hyperthermia?

Best First Treatment for Thyroid Storm

After initiating isotonic fluids, propranolol (Option D) is the best first treatment in addition to supportive measures for this patient with thyroid storm.

Rationale for Beta-Blocker as First-Line Treatment

Beta-blockers, specifically propranolol, should be administered immediately to control the life-threatening cardiovascular manifestations of thyroid storm. 1, 2 This patient presents with classic features of thyroid storm: severe tachycardia (HR 140), hypertension (BP 150/100), hyperthermia (39.5°C), altered mental status (agitation), and likely thyromegaly on neck exam in the setting of recent hyperthyroid symptoms (palpitations, weight loss). 2, 3

Why Propranolol is the Optimal Choice

• Propranolol provides dual benefit by both controlling adrenergic symptoms AND blocking peripheral conversion of T4 to T3, which is unique among beta-blockers. 1, 2, 4
• The American College of Cardiology and American Heart Association recommend propranolol as the first-line beta-blocker with typical dosing of 60-80 mg orally every 4-6 hours. 1
• Treatment must begin immediately based on clinical suspicion without waiting for laboratory confirmation, as mortality can rise to 75% with treatment delays. 2, 5

Treatment Algorithm for Thyroid Storm

The proper sequence matters critically:

1. Beta-blocker (propranolol) first to control cardiovascular symptoms and prevent cardiovascular collapse 1, 2
2. Thionamide (propylthiouracil or methimazole) to inhibit thyroid hormone synthesis 1, 2
3. Iodine 1-2 hours AFTER thionamides to block hormone release - never before thionamides as this worsens thyrotoxicosis 1, 2
4. Corticosteroids to reduce peripheral T4 to T3 conversion 1, 2

Why Other Options Are Incorrect

• Iodine (Option C) cannot be given first - it must be administered 1-2 hours AFTER starting thionamides, or it will worsen thyrotoxicosis by providing substrate for additional hormone synthesis. 1, 2
• Hydrocortisone (Option B) is important but not the first treatment - corticosteroids are part of the multi-drug regimen but beta-blockade takes priority for immediate cardiovascular stabilization. 1, 2
• Dantrolene (Option A) is used for malignant hyperthermia, not thyroid storm. 6

Critical Pitfalls to Avoid

• Never administer iodine before thionamides - this is a common and dangerous error that can precipitate cardiovascular collapse. 1, 2
• Use caution with propranolol in severe heart failure - in hemodynamically unstable patients requiring vasopressor support, esmolol (ultra-short-acting beta-blocker) is preferred due to its rapid onset and short half-life allowing careful titration. 1, 2, 7
• One case report documented propranolol-induced circulatory collapse in a patient with underlying thyrocardiac disease, emphasizing the need for careful monitoring. 7
• If beta-blockers are contraindicated, diltiazem 15-20 mg IV over 2 minutes can be used as an alternative for rate control. 1, 2

Monitoring Requirements

• All patients require hospitalization; severe cases like this one need ICU admission. 2, 3
• Obtain immediate endocrinology consultation. 2
• Monitor for cardiac complications including heart failure and arrhythmias. 2, 3
• Watch for agranulocytosis with thionamide use (presents with sore throat and fever). 2
• Clinical improvement should occur within 12-24 hours; if not, consider early thyroidectomy. 5