Today we will start a miniseries on endocrine emergencies. Myxedema coma -severe hypothyroidism Clinical Features: -Hypothermia -Hypoglycemia -Hypoventilation--> hypoxia, hypercapnia, -Hyponatremia in 50% of patients -Hypotension & bradycardia -Hypomentation, obtunded can conversely have psychosis -Myxedema, nonpitting edema due to deposition mucin & albumin --> can complicate airway -Seizure
Work up: -Work up other pathology -TSH (high) -T4 (low) -T3 (low) -Cortisol (to check for adrenal insufficiency)
Specific treatment: -Initial dose 200-400mcg T4(levothyroxine) IV then daily 50-100mcg IV -Plus initial dose 5-20mcg T3(liothyronine) then 2.5-10mcg every 8 hours, continue T3 until patient stable -Optimal dose may be moderate dose, use lower doses in older frailer patients -Stress dose steroid hydrocortisone 100 mg every 8 hours
Disposition: ICU
Thyroid storm -too much thyroid, think elevated metabolism and stress response Clinical Features: -Tachycardia--> 60% patients have tachycardia or atrial fibrillation -CHF -Arrhythmia -Cardiac arrest -Hyperpyrexia often 104-106 -Agitation -Psychosis -May be obtunded or comatose -Hand tremor -Diaphoretic -Nausea, diarrhea, and vomiting
Work up: -TSH (low) -T3 (high) -T4 (high) may also have hyperglycemia, mild hypercalcemia, leukocytosis,
Specific treatment: (it is important to give betablocker before inhibiting thyroid hormone synthesis) 1. Propanolol 0.5-1mg IV over 3-5 minutes repeat every 5-10 minutes till heart rate <100 -OR use esmolol, load 250-500mcg/kg, infusion 50-100mcg/kg/min -CHF is high output still give test doses betablocker 2. PTU (propylthiouracil) load 600-1000mg then 300mg every 6 hours give PO, NG, PR (preffered in pregnancy) -OR use methimazole20-30 mg every 6 hours 3. corticosteroid, hydrocortisone 100mg IV every 8 hours -OR use Dexamethazone 2-4mg IV every 6 hours (dexamethazone does not scew cortisol tests) 4. inhibit thyroid production with inorganic iodine -Potassium Iodide: 5 oral drops -OR Lugol's solution 10 oral drops