Thyroid Storm

Snapshot

A 34-year-old woman with a history of hypothyroidism presents to the emergency department with altered mental status. According to the husband, she woke up this morning generally confused and was unable to answer questions. She had 3 episodes of nonbloody, nonbilious emesis shortly after and has been agitated since. She was recently discharged from the hospital status post-elective cesarean section. Her temperature is 99.5°F (37.5°C), blood pressure is 160/100 mmHg, pulse is 142/min, and respirations are 22/min. Laboratory studies show low TSH.

Introduction

Clinical definition
- life threatening condition characterized by symptoms of severe thyrotoxicosis (excessive thyroid hormone in the body)
- often precipitated by an acute event/trigger
Epidemiology
- risk factors
  - longstanding, untreated hyperthyroidism
  - surgery
  - trauma
  - infection
  - parturition
  - irregular use or discontinuation of antithyroid drugs
Associated conditions
hyperthyroidism

Presentation

Symptoms
- agitation
- anxiety
- delirium
- coma
- nausea/vomiting
- diarrhea
- abdominal pain
Physical exam
- tachycardia (can exceed 140/min)
- hypotension/hypertension
- hyperpyrexia
- jaundice
arrythmias

Studies

Thyroid function tests
- usually not more profound than that seen in patients with uncomplicated thyrotoxicosis
- low TSH
- high free T4 and/or T3
Liver functioning test
may see abnormal liver functioning test

Differential

Sepsis
- distinguishing factors
  - rarely the extreme tachycardia seen in thyroid storm
thyroid functioning tests will likely be normal in sepsis

Treatment

Management approach
- management should be immediate following clinical diagnosis and patients should be managed at the intensive care unit (ICU)
First-line
- beta-blocker
  - control the symptoms and signs (e.g., tachycardia) induced by increased adrenergic tone
  - e.g., propranolol
- thionamide
  - blocks new hormone synthesis
  - effective within 1-2 hours post-administration
  - e.g., propylthiouracil (PTU) or methimazole
- iodine solution
  - blocks release of thyroid hormone
    - known as the Wolff-Chaikoff effect
    - effective within 1-2 hours post-administration
- glucocorticoid
  - reduces T4 to T3 conversion
  - promotes vasomotor stability
  - reduce autoimmune process in Grave disease
  - treat associated relative adrenal insufficiency
Long-term management
in patients with Graves disease, definitive therapy with radioactive iodine or thyroidectomy may be indicated

Complications