Myxedema coma (severely low thyroid hormone)

Description Decreased conscious...

Description

Decreased consciousness and confusion as a result of severe, longstanding low level of thyroid hormone in the body (hypothyroidism). Thyroid hormone is necessary to maintain normal body functions such as metabolism, body temperature, blood sugar (glucose), and blood pressure. Myxedema coma is a life-threatening complication of hypothyroidism and is more commonly seen in elderly and female patients. Most patients have a history of hypothyroidism, previous thyroid surgery or radioactive destruction of the thyroid. Physical stress can cause a patient with hypothyroidism to acquire the more serious form of myxedema. Common stressors include: infections, trauma, stroke, medications (narcotics, anesthesia, lithium and amiodarone), congestive heart failure, and intestinal bleeding. Failure to take prescribed thyroid medication can also result in the disorder.

Symptoms

Symptoms may vary but include: lethargy, low body temperature (hypothermia), confusion, hallucinations, seizures, coma, swelling of the body (edema), swelling around the eyes, tongue swelling, breathing problems, fluid collections around the heart (pericardial effusion) and lung (pulmonary effusion), slow heart rate (bradycardia), depression, hoarseness, dry skin, weight gain, change in menstrual cycles, and severe constipation.

Tests

Common tests used for diagnosis and treatment

Workup:
A history and physical exam will be done. Blood tests including a thyroid function (TSH, T3 and T4 levels) will also be done. Imaging tests such as a CT scan or MRI may be performed to rule out other causes of coma.

Tests:
Complete blood count (CBC), Comprehensive metabolic panel (CMP), CT Scan, Electrocardiogram (EKG), Magnetic resonance imaging (MRI), Thyroid function tests, Thyroid stimulating hormone (TSH), X-ray

Other Specific Tests: TFT, T3, T4

Treatment

Emergency treatment is needed and may include the following: warming the patient, assisting the breathing with a tube (intubation and mechanical ventilation), antibiotics if an infection is suspected, and thyroid hormone administration. Thyroid replacement is given intravenously and consists of both T3 and T4 since patients with myxedema are sometimes not able to convert the T4 into T3 themselves. The thyroid is given gradually to prevent stressing the heart.