[Coma in myxedema--a rare complication of hypothyroidism. Possible iatrogenic factors should be taken into account].

Myxedema coma is the most severe form of hypothyroidism and is characterized by extreme hypothermia, bradycardia, central hypoventilation and hypoxia. Common causes are intercurrent diseases, interruption of thyroid hormone treatment, or an overdose of sleeping pills or sedatives. The diagnosis is usually readily established on the basis of very high serum TSH and low T4 levels. Consideration must also be given to an extra-thyroidal influence on the hormone levels. Intensive care treatment involving intravenous high-dose L-thyroxine and the reversal of hypoxia improve the prognosis of the serious disease.