Thyroid storm

Background

• Mortality
  • Without treatment: 80-100%
  • With treatment: 15-50%

Precipitants

1. Infection
2. Trauma
3. Surgery
4. DKA
5. Withdrawal of thyroid medication
6. Iodine administration
7. MI
8. CVA
9. PE

Diagnosis

1. Classic Triad:
   1. Hyperthermia
   2. Tachycardia
   3. AMS
      1. Agitation, confusion, delirium stupor, coma, seizure
2. May also have:
   1. CHF
   2. Palpitations
   3. Dyspnea
   4. Increased pulse pressure
   5. A-fib

Burch & Wartofsky Diagnostic Criteria

I. Thermoregulatory dysfunction (Temperature)

99-99.9	5
100-100.9	10
101-101.9	15
102-102.9	20
103-103.9	25
104.0	30

II. Central nervous system effects

Mild (Agitation)	10
Moderate (delirium, psychosis, extreme lethargy)	20
Severe (seizure, coma)	30

III. Gastrointestinal-hepatic dysfunction

Moderate (diarrhea, n/v, abd pain)	10
Severe (unexplained jaundice)	20

IV. Cardiovascular dysfunction (tachycardia)

99-109	5
110-119	10
120-129	15
130-139	20
140	25

V. Congestive heart failure

Mild (pedal edema)	5
Moderate (bibasilar rales)	10
Severe (pulm edema, A. fib)	15

VI. Precipitant history

Negative	0
Positive	10

Scoring

• >45 = Highly suggestive of thyroid storm
• 25-44 = Suggestive of impending storm
• <25 = Unlikely to represent storm

DDX

1. Infection
2. Sympathomimetic ingestion (cocaine, amphetamine, ketamine)
3. Heat exhaustion
4. Heat stroke
5. Delirium tremens
6. Malignant hyperthermia
7. Malignant neuroleptic syndrome
8. Hypothalamic stroke
9. Pheochromocytoma
10. Medication withdrawal (cocaine, opioids)
11. Psychosis
12. Organophosphate poisoning

Work-Up

• Chemistry
• CBC
• TSH/Free T3/T4
• Cortisol level (rule-out concurrent adrenal insufficiency)
• ECG
• Rule-out infection:
  • CXR
  • Blood culture

Treatment

1. Supportive care
   1. Fever
      1. Cooling measures, acetaminophen (avoid aspirin)
   2. Dehydration/hypoglycemia
      1. D5NS (most pts have depleted glycogen stores)
   3. Cardiac decompensation (CHF, A-fib)
      1. Rate control, inotropes, diuretics as needed
2. Block new hormone synthesis
   1. PTU 600-1000 mg PO or PR followed by 200-250mg q4hr
      1. Preferred to methimazole b/c also blocks T4>T3 conversion
   2. Methimazole 20-25mg q4hr
      1. Longer acting than PTU
3. Block hormone release
   1. Wolff-Chaikoff effect: incr iodine concentration leads to transient decrease of T3/T4
   2. Potassium iodide 5 gtt q6hr (Give 1hr after PTU)
      1. 1st line
   3. Lithium 300mg q6hr
      1. Consider if iodine allergic
4. Block beta-adrenergic tone and peripheral T4>T3 conversion
   1. Propranolol PO 60-80 q4hr (if pt can tolerate PO)
   2. Propranolol IV 1mg over 10 min; if tolerates then 1-3mg boluses q3hr
   3. Esmolol 250-500mcg/kg loading dose, then 50-100mcg/kg/min
5. Treat possible adrenal insufficiency (also blocks T4>T3)
   1. Hydrocortisone 100-300mg IV bolus, followed by 100mg q8hr

See Also

Hyperthyroidism

Sources

• Tintinalli
• UpToDate
• Burch, HB, Wartofsky, L, Endocrinol Metab Clin North Am 1993; 22:263