Differentiate thyroid storm from myxedema coma and identify initial management steps for each.

• A. Thyroid storm: fever, tachycardia, agitation; myxedema coma: hypothermia, coma; treat storm with PTU/methimazole, iodine, beta-blocker, steroids; treat myxedema coma with IV thyroid hormone and supportive care
• B. Thyroid storm: hypothermia; myxedema coma: fever; treat storm with levothyroxine; treat coma with iodine
• C. Thyroid storm: bradycardia; myxedema coma: tachycardia; treat storm with iodine; treat coma with ACE inhibitors
• D. Thyroid storm and myxedema coma are the same; treat with diuretics

Answer: (A)

Thyroid storm and myxedema coma are two extreme thyroid emergencies that present with opposite clinical pictures and require distinct initial management. The key distinction is the patient’s vital signs and mental status: thyroid storm shows fever, tachycardia, agitation or delirium, and often GI symptoms; myxedema coma presents with hypothermia, severely reduced mental status or coma, and often hypotension and hypoventilation.

For thyroid storm, the goal is rapid control of thyroid hormone effects and the adrenergic surge. Start antithyroid coverage with a thionamide such as propylthiouracil (which also inhibits peripheral conversion of T4 to T3), then give iodine to block hormone release after the thionamide has begun. A beta-blocker is given to blunt tachycardia and sympathetic overdrive, and corticosteroids are used to treat potential adrenal insufficiency and to reduce peripheral conversion of T4 to T3. Supportive care is essential, including fluid and electrolyte management, fever control, and addressing any precipitating factor like infection or surgery.

In myxedema coma, the priority is life-supportive care and replacing deficient thyroid hormone. This involves airway protection and hemodynamic support, along with intravenous thyroid hormone replacement (levothyroxine, sometimes with liothyronine) and stress-dose steroids until adrenal insufficiency is ruled out. Also provide warming, careful fluid management, and treatment of hypoventilation or organ dysfunction.

The contrasting features and the tailored pharmacologic steps above explain why this approach is correct: each emergency centers on the direction of thyroid activity and uses therapies that either rapidly suppress excess hormone action or replace deficient hormone activity, with appropriate supportive measures.