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)

Temp	Points
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)	10pts
Moderate (delirium, psychosis, extreme lethargy)	20pts
Severe (seizure, coma)	30pts

III. Gastrointestinal-hepatic dysfunction

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

IV. Cardiovascular dysfunction (tachycardia)

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

V. Congestive heart failure

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

VI. Precipitant history

Negative	0pts
Positive	10pts

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 (ice packs & cooling blankets), 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 beta-adrenergic tone and peripheral T4>T3 conversion
   1. Contraindications are same as for other medical conditions (e.g. CHF)
   2. Propranolol PO 60-80 q4hr (if pt can tolerate PO) OR
   3. Propranolol IV 1-2mg over 10 min; if tolerates then 1-3mg boluses q3hr OR
   4. Esmolol 250-500mcg/kg loading dose, then 50-100mcg/kg/min - B1 selective so can be used in pt with active CHF, asthma, etc.
3. 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. Note black box warning of hepatotoxicity
   2. Methimazole 20-25mg q4hr
      1. Longer acting than PTU
4. Block hormone release: Only after hormone synthesis is inhibited
   1. Wolff-Chaikoff effect: incr iodine concentration leads to transient decrease of T3/T4
      1. Likely due to suppression of already-formed thyroid hormone release
   2. Potassium iodide (SSKI)
      1. Give 1hr after PTU to prevent increased hormone production (Jod-Basedow effect)
      2. 1st line
      3. 5 gtt q6hr
         1. Avoid potassium iodide if patient is on amiodarone
         2. Can substitute radiocontrast dyes (Iopanoic acid, ipodate and iopanoate) or oral lugol solution
   3. Lithium
      1. Consider if iodine allergic
      2. 300mg q6hr
5. Treat possible adrenal insufficiency (also blocks T4>T3)
   1. Hydrocortisone 100-300mg IV bolus, followed by 100mg q8hr OR Dexamethasone 2mg IV q6hr
6. Plasmapheresis
7. Identify precipitant (ie med noncompliance, DKA, infection)

Disposition

• Admission to ICU

See Also

Hyperthyroidism

Sources

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