Thyroid Emergencies

LITERATURE

• 2019 Review Thyroid Emergencies 
• 2013 Endocrine Causes of Dangerous Fever 

THYROID STORM

• Etiology
  • Graves (60-80%), toxic adenoma, thyroiditis
  • Precipitants: infection, surgery, CVA, MI, PE
• Sx/PE
  • Fever (may be >40C), sinus tachycardia/supraventricular arrhythmias +/- high output heart failure
  • Agitation/psychosis/seizures, diarrhea/vomiting/jaundice
• Diagnosis (Burch-Wartofsky score)
  • Points are assigned and the score totaled. When not possible to distinguish a finding due to an intercurrent illness from that of thyrotoxicosis, a higher point score is given in order to favor empiric therapy given the potential high mortality.
  • Interpretation: Based on the total score, the likelihood of the diagnosis of thyrotoxic storm is unlikely if <25, impending if between 25–44, likely if between 45–60, and highly likely if >60.

DIAGNOSTIC CRITERIA FOR THYROTOXIC CRISIS

			Points
Thermoregulatory dysfunction
Temperature (°F):	99–99.9		5
	100–100.9		10
	101–101.9		15
	102–102.9		20
	103–103.9		25
	≥104		30
Central nervous system effects
Absent			0
Mild agitation			10
Delirium, psychosis, lethargy			20
Seizure or coma			30
Gastrointestinal dysfunction
Absent			0
Diarrhea, nausea, vomiting, or abdominal pain			10
Unexplained jaundice			20
Cardiovascular dysfunction
Tachycardia (beats/min):	90–109		5
	110–119		10
	120–129		15
	130–139		20
	≥140		25
Congestive heart failure:	Absent		0
	Mild (edema)		5
	Moderate (bibasilar rales)		10
	Severe (pulmonary edema)		15
Atrial fibrillation:	Absent		0
	Present		10
History of precipitating event (surgery, infection, etc.)
		Absent	0
		Present	10

• Treatment
  • Decrease hormone synthesis; Address peripheral circulation; Treat precipitator; Supportive care
    • PTU (also inhibits peripheral T4 to T3 conversion) 500-1000mg load PO/IV, then 250mg Q4h (avoid in liver dysfunction) or
    • Methimazole 29mg PO every 4-6 hours
    • AFTER SYNTHESIS BLOCKING AGENT:  Iodine (KI 8 drops q6h) (if allergic to iodine then lithium carbonate can be used)
    • Corticosteroids (prophylaxis against relative adrenal insufficiency): hydrocortisone 300mg IV load, then 100mg IV Q8
    • B-blockade (block peripheral effects of hormone): propranolol 60-80 Q4hr or esmolol gtt
      • block release/synthesis of hormone: potassium iodide 5 drops PO Q6hr; start 1 hr after antithyroid drug
    • Supportive care: volume resuscitate, respiratory support PRN
    • Antipyretics: APAP, cooling blanket. AVOID salicylates (they can increase T4)!

MYXEDEMA COMA

• Definition: hypothyroidism + stupor/confusion/coma + hypothermia + low T4 and T3 (See Scoring System in article, 60 or greater 
• Sx/PE: poor memory, apathy, weakness (hypercapneic respiratory failure), fatigue, cold intolerance, constipation (can progress to ileus), dry skin, menstrual irregularities, bradycardia, hypoNa, hypoglycemia,
• Tx BEFORE LABS RETURN! MORTALITY IS 30-40%
  • 1^st= glucocorticoids (give bc decreased adrenal reserves)- hydrocortisone 100mg followed by 50-100 mg IV Q 6-8hrs
  • 2^nd= thyroid hormone (type is controversial many favor giving both)
    • T4: IV 4mcg/kg, then 100mcg IV at 24 hrs, then 50 mcg/day IV (lower dose for elderly or heart patients) AND/OR
    • T3: 10 mcg-20 mcg q4h x 24h then 10mcg q6h x 48h until pt begins PO T4 (lower amount if also given T4, 10mcg q8h x 72h)
      • Caution in older pts and pts with CAD and arrhythmia.
    • Correct hypovolemia, hyponatremia, PRN vasopressors