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Difficulty: HardPharmacologic Interventions

A 32-year-old woman is brought to the intensive care unit by emergency medical services due to severe agitation, delirium, and a temperature of 39.8°C (103.6°F). Her blood pressure is 158/72 mm Hg, and her pulse is 165/min and irregular. Physical examination reveals profuse diaphoresis, a diffusely enlarged and non-tender thyroid gland, bilateral proptosis, and a pronounced bilateral resting tremor. An electrocardiogram shows atrial fibrillation with a rapid ventricular response. She has a history of Graves disease but has been nonadherent to her medications for the past four months. Laboratory studies confirm a diagnosis of thyroid storm.

Arrange the following therapeutic interventions in the correct chronological order, from the most immediate initial action to the final definitive management step.

  1. 1Administer intravenous propranolol
  2. 2Administer oral propylthiouracil
  3. 3Administer oral potassium iodide solution
  4. 4Perform radioactive iodine ablation

Answer

The correct chronological management sequence for thyroid storm is: intravenous propranolol, followed by propylthiouracil, followed by potassium iodide (delayed by 1 hour), and eventually radioactive iodine ablation as an outpatient.
The precise chronological order for thyroid storm management focuses first on controlling peripheral adrenergic effects (beta-blocker), second on stopping new hormone synthesis (thionamide), third on blocking hormone release (iodine, delayed to prevent fueling synthesis), and finally on definitive long-term care (RAI or surgery once euthyroid).

Step-by-Step Solution

1
Administer intravenous propranolol
Blunts the systemic sympathetic surge
Cardiovascular collapse is the most common cause of death in thyroid storm. Beta-blockers provide immediate life-saving hemodynamic stabilization.
2
Administer oral propylthiouracil (PTU)
Halts production of new T3 and T4
Thionamides block thyroid peroxidase. This step must precede iodine administration to prevent the iodine from being utilized to manufacture more thyroid hormone.
3
Administer oral potassium iodide solution
Blocks the release of stored thyroid hormone (Wolff-Chaikoff effect)
Must be given at least 1 hour after PTU administration. If given earlier, the massive iodine load will rapidly worsen the thyrotoxicosis.
4
Perform radioactive iodine ablation
Definitive destruction of overactive thyroid tissue
Only performed electively weeks later once the patient is clinically euthyroid, as the procedure itself can transiently release stored hormone and precipitate a recurrent storm.

Key Concept

Chronological Pharmacologic Management of Thyroid Storm
Estimated Time:1m 30s
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Topics

Pharmacologic Interventions

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