The Diagnosis and Management of Hypothyroidism

Bhuvana Guha, MD, Guha Krishnaswamy, MD, And Alan Peiris, MD, PhD, MRCP

Disclosures

South Med J. 2002;95(5):475-480. 

In This Article

Myxedema Coma

Myxedema coma is a severe form of hypothyroidism that is associated with a significant mortality rate.[24] The disorder is most often seen in patients with a history of hypothyroidism who are exposed to stressful conditions, such as surgery or extreme cold. Other events, such as concurrent cerebrovascular accidents, infections (eg, pneumonia), hypothermia, trauma, and the use of medications (eg, analgesics, sedative tranquilizer drugs, general anesthesia, narcotics, amiodarone, and lithium) can also precipitate myxedema coma.[24] The principal clinical features, in addition to the other manifestations of hypothyroidism reviewed earlier, include hypothermia, altered consciousness, delirium, hypoventilation (resulting in respiratory failure and hypercapnia), cardiac dysfunction (bradycardia, decreased cardiac output, and hypotension), constipation, and urinary retention. Periorbital edema, macroglossia, and generalized swelling may be seen. Electrolyte abnormalities, such as hyponatremia, occur in these critically ill patients, and are often due to excessive fluid retention. Elevated creatinine phosphokinase levels suggest the presence of rhabdomyolysis. Other laboratory testing abnormalities observed include hypoglycemia, dyslipidemia and anemia. The term myxedema coma may be a misnomer, since patients may have neither coma nor evidence of peripheral, nonpitting edema.[25] It is important to diagnose and treat the patient with myxedema coma aggressively because, if untreated, the disorder has a very high mortality rate. Treatment usually requires admission to a medical intensive care unit and the administration of intravenous levothyroxine.[25] Many patients also require concomitant administration of hydrocortisone until coexisting adrenal insufficiency has been excluded. Associated complications, such as infections, electrolyte disturbances, hypoglycemia, cardiorespiratory problems, hypothermia, and rhabdomyolysis, also require treatment. In spite of aggressive management, studies have suggested mortality rates between 30% and 60%, especially in the very elderly patient or those with persistent hypothermia or cardiac dysfunction.

CME Information

The print version of this article was originally certified for CME credit. For accreditation details, contact the publisher. (link to publisher contact information: Southern Medical Assocation, 35 Lakeshore Dr, Birmingham Alabama 35209, telephone: (205)945-1840.

Disclosure

In publishing this section in Southern Medical Journal, the Southern Medical Association recognizes educational needs of physicians in all specialties, especially those in primary care, for current information regarding thyroid disorders. In this section, authors may have included discussions about drug interventions, whether Food and Drug Administration approved or unapproved. Therefore, it is incumbent on physicians reading this section to be aware of these factors in interpreting the contents and evaluating recommendations. Moreover, views of authors do not necessarily reflect the opinions of the Southern Medical Association. Every effort has been made to encourage the author to disclose any commercial relationships or personal benefit that may be associated with this section. If the author disclosed a relationship, it is indicated below. This disclosure in no way implies that the information presented is biased or of lesser quality, but allows participants to make informed judgments regarding program content.

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