Examkin

Question

Difficulty: MediumEndocrinology and Metabolism

A 32-year-old woman is brought to the emergency department by her family due to severe agitation, confusion, and palpitations that started earlier today. She has a known history of Graves disease but admits to abruptly stopping her antithyroid medications three months ago. Her temperature is 40.0∘C40.0^\circ\text{C} (104.0∘F104.0^\circ\text{F}), blood pressure is 165/95 mmHg165/95\text{ mmHg}, pulse is 155/min155/\text{min} and irregular, and respiratory rate is 24/min24/\text{min}. Physical examination reveals a delirious, severely diaphoretic patient with a diffusely enlarged and non-tender thyroid gland. Fine tremors are noted in her extremities. An electrocardiogram shows atrial fibrillation with a rapid ventricular response. A clinical diagnosis of thyroid storm is made, and the patient is admitted to the intensive care unit.

Arrange the following therapeutic interventions in the most appropriate chronological sequence for managing this patient's condition.

  1. 1Administer a beta-adrenergic antagonist (e.g., propranolol)
  2. 2Administer a thionamide (e.g., propylthiouracil)
  3. 3Administer an iodine solution (e.g., potassium iodide)
  4. 4Proceed with definitive therapy (e.g., radioactive iodine ablation)

Answer

The correct sequence for managing a thyroid storm is: 1) Administer a beta-adrenergic antagonist, 2) Administer a thionamide, 3) Administer an iodine solution, and 4) Proceed with definitive therapy.
The correct management sequence for thyroid storm begins with stabilizing the patient's severe adrenergic symptoms using a beta-blocker. Once stabilized, the underlying hyperthyroidism is treated sequentially by first blocking new hormone synthesis with a thionamide (like PTU), and then blocking the release of preformed hormone with an iodine solution (like SSKI). The thionamide must precede the iodine by at least 1 hour to prevent the iodine from being used to synthesize new hormone. Finally, after the patient survives the acute crisis and returns to a euthyroid state over weeks to months, definitive therapy such as surgery or radioactive iodine can be safely performed.

Step-by-Step Solution

1
Stabilize hemodynamics and control sympathetic overactivity.
A beta-blocker (like propranolol) is given first.
Immediate reduction of heart rate and myocardial oxygen demand prevents cardiovascular collapse.
2
Halt de novo thyroid hormone synthesis.
A thionamide (like propylthiouracil) is given next.
Blocking thyroid peroxidase prevents the gland from utilizing new iodine to make more hormone.
3
Inhibit the release of preformed thyroid hormone.
An iodine solution (like potassium iodide) is given at least 1 hour after the thionamide.
Iodine blocks hormone release via the Wolff-Chaikoff effect, but giving it before a thionamide would dangerously fuel further hormone production.
4
Ensure long-term resolution.
Definitive therapy is planned for a later date.
Radioactive iodine ablation or thyroidectomy can only be performed safely once the patient is euthyroid.

Key Concept

The chronological pharmacological management of thyroid storm prioritizes sympathetic control (beta-blockers), followed by blocking synthesis (thionamides), followed by blocking release (iodine), and finally definitive therapy once stabilized.
Rate this question

Topics

Endocrinology and Metabolism

More questions from this topic