Myxedema coma medical therapy

All the patients with myxedema coma should be admitted to ICU and treatment must be started as quickly as possible. Given the clinical suspicion of myxedema coma, initiate replacement therapy without waiting for laboratory results. The empirical use of glucocorticoids should be part of the initial therapeutic protocol as severe hypothyroidism induces a lower adrenal response to stress. Administration of glucocorticoids is independent of whether or not there is simultaneous adrenal insufficiency. Since thyroid hormone speeds up metabolism of cortisol and its plasma levels may be decreased in the presence of adrenal insufficiency, the glucocorticoids should always be given prior to thyroid replacement because otherwise they could precipitate an adrenal crisis. Hydrocortisone must be given in doses of, 50- 100 mg intravenously (IV) every 6-8 h for 7 to 10 days or until hemodynamically stabilizes the patient. Identify and properly treat the precipitating factor.

Treatment of myxedema coma should be performed in an Intensive Care Unit (ICU) and start with as quickly as possible. ^[1][2][3][4]

• Preferred regimen (1): levothyroxine (LT4)200-400 μg in IV bolus in the first 48 hours, followed by one dose more physiological 50-100 μg IV daily until you can administer orally.
  • Note-some propose to start with larger doses of 300-500 μg.
  • Note-To avoid the risk of cardiac complications continuous cardiac monitoring with dose reduction of thyroid hormone to see ischemic changes or arrhythmias.

• Alternative regimen (1): 10 μg of T3 in IV bolus with the dose of T4 and continue with 10 μg every 8-12 hs along the T4 until recovery. OR
• Alternative regimen (2): T4 + T3 5-20 μg IV bolus as loading dose, followed by 2.5-10 μg every 8 h.

• Broad-spectrum antibiotics should be started immediately given the high incidence of infections in comatose patients.
• Ventilation is initiated to reduce CO2 retention and respiratory acidosis.
• Hypothermia must be treated using passive methods(blankets) since they can generate greater vasodilation. Avoid using rewarming techniques.
• The treatment of hypotension should be energetic by evaluating the best option, either volume replenishment or drug pressures with dynamic monitoring.
• Hyponatremia and hypoglycemia can be corrected by administering electrolytes and dextrose.
  • Correction of hyponatremia requires low hypertonic saline solution (50-100 ml NS al 3%), sufficient to increase the sodium concentration at about 2 mEq / l in the initial course of treatment, followed by an IV bolus of furosemide 40 to 120 mg promote watery diuresis.
  • Rapid correction of the hyponatremia can cause a complication osmotic demyelination syndrome (central pontine myelinolysis).
  • After reaching a sodium level greater than 120 mEq / l, the water restriction is sufficient to completely normalize the hyponatremia.
• Another therapeutic option, is to administer an antidiuretic hormone antagonist such as tolvaptan or conivaptan.