MYXEDEMA coma is the extreme clinical expression of hypothyroidism. It is characterized by coma, hypothermia, cardiovascular collapse, hypoventilation, and severe metabolic derangements, including low serum sodium, hypoglycemia, and lactic acidosis. Mild to moderate hypometabolism, lethargy, and sleepiness secondary to untreated hypothyroidism is not myxedema coma and should not be treated as such.
Generally, myxedema coma requires several years of untreated hypothyroidism to develop, and usually, it occurs in elderly people who have been without medical care. Before treatment for myxedema coma is initiated, other medical conditions causing similar signs and symptoms should be ruled out.
Prognosis is guarded (greater than 50% mortality), and success depends upon prompt institution of appropriate therapy.1-3
Administration of Thyroid Hormone.—
The rational course of therapy is to deliver thyroid hormone to the patient. However, myxedematous patients are frequently extremely sensitive to the metabolic effects of thyroid hormones and may sustain cardiac damage. Nevertheless, it
Newmark SR, Himathongkam T, Shane JM. Myxedema Coma. JAMA. 1974;230(6):884-885. doi:10.1001/jama.1974.03240060054038