Myxedema coma represents the extreme, life-threatening end of severe hypothyroidism. This protocol addresses the specific clinical scenario in which a patient presents with mental status changes, hypothermia, and stupor — a medical emergency requiring urgent structured management.
Rarely, severe hypothyroidism progresses to myxedema coma, most commonly encountered in older patients. The clinical picture includes altered mental status (lethargy, confusion, psychosis), hypothermia, hypotension, bradycardia, hypoventilation, and diffuse nonpitting edema. Mortality ranges from 25% to 60%, making prompt, evidence-based management essential.
Management begins with intensive care unit admission. The approach centres on thyroid hormone replacement with levothyroxine, with the full protocol specifying administration strategy, route considerations, and the criteria under which a combination approach may be used. Supportive management to address the possibility of concurrent adrenal insufficiency is incorporated — the complete sequencing and transition criteria are in the full protocol.
The primary biochemical marker of response: the thyroid-stimulating hormone (TSH) level should fall by 50% per week on adequate treatment.
Rarely, severe hypothyroidism can cause myxedema coma, a medical emergency most commonly found in older patients with primary hypothyroidism, with a 25% to 60% mortality rate.
Clinical features include hypothermia and mental status changes (e.g., lethargy, confusion, psychosis), hypotension, bradycardia, hypoventilation, and diffuse nonpitting edema.
Levothyroxine should be given as a slow intravenous bolus of 200 to 400 mcg initially, followed by 50 to 100 mcg (about 1.6 mcg per kg) orally per day.
Stress-dose glucocorticoids (e.g., 100 mg of hydrocortisone intravenously every eight hours) should be administered until adrenal insufficiency is ruled out.
The TSH level should drop by 50% per week on adequate treatment.
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