Internal Medicine · Year 3 · from Internal Medicine

Case 1: Graves Disease with Thyroid Storm

Patient Demographics

  • Age: 34 years
  • Sex: Female
  • Occupation: Marketing executive

Chief Complaint

"I have a high fever, my heart is racing, and I feel like I'm going crazy."

History of Present Illness

The patient presents to the emergency department with fever, palpitations, and agitation. She reports a 3-month history of unintentional weight loss (15 pounds), heat intolerance, and tremors. Over the past week, she developed an upper respiratory infection with cough and sore throat. Today she awoke with severe palpitations, drenching sweats, high fever, and extreme anxiety. Her husband notes she has been increasingly confused and agitated throughout the day. Past medical history includes a diagnosis of hyperthyroidism 2 years ago for which she was prescribed methimazole, but she stopped taking it 6 months ago because she "felt fine."

Vital Signs

  • Temperature: 104.2 degrees F (40.1 degrees C)
  • Blood pressure: 168/72 mmHg (widened pulse pressure)
  • Heart rate: 156 bpm, irregularly irregular
  • Respiratory rate: 26/min
  • Oxygen saturation: 94% on room air

Physical Examination

General: Diaphoretic, agitated, restless, unable to sit still HEENT: Lid lag, exophthalmos bilateral, moist mucous membranes Neck: Diffusely enlarged thyroid gland (goiter), non-tender, audible bruit over thyroid Cardiovascular: Tachycardic, irregularly irregular (atrial fibrillation), hyperdynamic precordium, systolic flow murmur Pulmonary: Tachypneic, clear to auscultation Extremities: Fine tremor of outstretched hands, warm and moist skin, pretibial myxedema Neurologic: Hyperreflexic, agitated, difficulty following commands, intermittently confused

Laboratory Findings

  • TSH: < 0.01 mIU/L (suppressed)
  • Free T4: 7.8 ng/dL (markedly elevated, normal 0.8-1.8)
  • Free T3: 18.2 pg/mL (markedly elevated, normal 2.3-4.2)
  • Thyroid stimulating immunoglobulin (TSI): Positive
  • WBC: 14,200/mcL
  • AST: 86 U/L
  • ALT: 78 U/L
  • Glucose: 186 mg/dL
  • Calcium: 11.2 mg/dL

Electrocardiogram

  • Atrial fibrillation with rapid ventricular response, rate 156 bpm
  • No ST-T wave changes

Burch-Wartofsky Point Scale (BWPS) for Thyroid Storm

  • Temperature 104.2 F (40.1 C): 25 points
  • Heart rate >140: 25 points
  • Atrial fibrillation: 10 points
  • Moderate agitation: 10 points
  • Mild hepatic dysfunction: 0 points
  • Precipitant present (infection): 10 points
  • Total: 80 points (>45 suggests thyroid storm)

Diagnosis

Thyroid storm secondary to Graves disease, precipitated by infection and medication non-compliance

Management

Step 1 - Block thyroid hormone synthesis:

  1. Propylthiouracil (PTU) 500-1000 mg PO/NG loading dose, then 250 mg every 4 hours
  • PTU preferred over methimazole in thyroid storm because it also blocks peripheral T4 to T3 conversion

Step 2 - Block thyroid hormone release (given 1 hour AFTER PTU):

  1. Potassium iodide (SSKI) 5 drops every 6 hours OR Lugol's solution 10 drops every 8 hours
  • Must wait 1 hour after PTU to prevent iodide from being used as substrate for new hormone synthesis (Wolff-Chaikoff effect)

Step 3 - Block peripheral effects and T4 to T3 conversion:

  1. Propranolol 60-80 mg PO every 4 hours (or IV if unable to take PO)
  • Controls tachycardia, tremor, and blocks peripheral conversion
  1. Esmolol IV infusion if rapid control needed

Step 4 - Glucocorticoids:

  1. Hydrocortisone 300 mg IV loading dose, then 100 mg IV every 8 hours
  • Blocks peripheral T4 to T3 conversion
  • Provides adrenal support (thyroid storm increases cortisol metabolism)

Step 5 - Supportive care:

  1. Active cooling with cooling blankets and acetaminophen
  • AVOID aspirin (displaces T4 from binding proteins, increasing free hormone)
  1. IV fluids for dehydration
  2. Treat precipitating cause (antibiotics for infection)
  3. ICU admission for monitoring
  4. Rate control for atrial fibrillation (may require digoxin in addition to beta-blocker)

Clinical Pearl

Thyroid storm is a clinical diagnosis - there is no laboratory value that distinguishes it from uncomplicated thyrotoxicosis. The Burch-Wartofsky Point Scale helps quantify the probability but clinical judgment remains paramount. The treatment follows a logical sequence: first block new hormone synthesis (PTU), then block hormone release (iodine - but only after synthesis is blocked), then block peripheral effects (beta-blocker and steroids). This patient demonstrates the typical precipitant pattern: a patient with underlying uncontrolled Graves disease who develops an acute stressor (infection) that tips them into the decompensated state of thyroid storm.

Clinical Image

Image Description: Clinical photograph demonstrating diffuse enlargement of the thyroid gland (goiter) characteristic of Graves disease. The enlarged thyroid may be visible as a fullness in the anterior neck.

Attribution: Image from Wikimedia Commons, by Michael Starks. Licensed under CC BY-SA 3.0. Source: https://commons.wikimedia.org/wiki/File:Goitre_-_Teknaf%2C_Bangladesh.jpg

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