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

Differential Diagnosis

• Infection
• Sympathomimetic ingestion (cocaine, amphetamine, ketamine)
• Heat Exhaustion
• Heat Stroke
• Delirium tremens
• Malignant Hyperthermia
• Malignant Neuroleptic Syndrome
• Hypothalamic stroke
• Pheochromocytoma
• Medication withdrawal (cocaine, opioids)
• Psychosis
• 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

Identify precipitant (ie med noncompliance, DKA, infection)

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

Decrease Peripheral Hormone Conversion

can use PO or IV Propranolol

1. Propranolol PO 60-80 q4hr (if pt can tolerate PO)
2. Propranolol IV 1-2mg over 10 min; if tolerates then 1-3mg boluses q3hr OR
   • Contraindications are same as for other medical conditions (e.g. CHF)

Block new hormone synthesis

PTU is prefered over methimazole because it will also bock T4->T3 conversion

1. PTU 600-1000 mg PO or PR followed by 200-250mg q4hr
   • Note black box warning of hepatotoxicity so check LFTs prior
   • Avoid in patients with significant liver disease and use Methimazole instead
2. Methimazole 20-25mg q4hr
   • Longer acting than PTU

Other Therapies

1. Esmolol 250-500mcg/kg loading dose, then 50-100mcg/kg/min
   • B1 selective so can be used in pt with active CHF, asthma, etc.
2. Potassium iodide (SSKI)
   • Give 1hr after PTU to prevent increased hormone production (Jod-Basedow effect)
   • Block hormone release: (Wolff-Chaikoff effect) only after hormone synthesis is inhibited. Iodine concentration leads to transient decrease of T3/T4
   • 5 drops (0.25 mL or 250 mg) orally every 6 hours
   • Avoid potassium iodide if patient is on amiodarone
   • Can substitute radiocontrast dyes (Iopanoic acid, ipodate and iopanoate) or oral lugol solution
3. Lithium carbonate<ref>Carroll R, Matfin G. Endocrine and metabolic emergencies: thyroid storm. Ther Adv Endocrinol Metab. 2010 Jun; 1(3): 139–145. Full Text
4. 300mg q6hrConsider if iodine allergic

=Adrenal Insufficiency Treatment

Often there may be associated adrenal insufficiency (also blocks T4>T3)

1. Hydrocortisone 100-300mg IV bolus, followed by 100mg q8hr OR Dexamethasone 2mg IV q6hr

Disposition

• Admission to ICU

See Also

• Hyperthyroidism

Sources

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