Myxedema Coma or Hypothyroid Coma- Symptoms, Diagnosis, and Treatment

Introduction:

Long-standing and untreated hypothyroidism can lead to a potentially life-threatening condition known as myxedema coma. The condition is also sometimes referred to as myxedema crisis. The condition often develops from a severe thyroid hormone deficiency that goes untreated, and the body fails to maintain homeostasis (steady internal, chemical, and physical state of the body). Some of the common symptoms of myxedema coma include hair thinning, puffy face, swelling of the skin, decreased heart rate, loss of appetite, etc.

What Is Myxedema Coma?

Myxedema coma, also known as hypothyroid coma, is a rare complication of hypothyroidism. There is a loss of brain function due to long-standing, untreated thyroid hormone deficiency. In addition, stressful events such as a heart attack, severe infection, or stroke often work as a precipitating factor. However, the patient does not have to be comatose or have non-pitting edema to be diagnosed as a case of a myxedema coma. Myxedema coma is a medical emergency requiring immediate medical aid.

Who Is More Affected by Myxedema Coma?

Hypothyroidism is four times more likely to affect women than men. Eighty percent of the cases are reported to be more in women. Myxedema coma has been reported to be more prevalent in patients who are over 60 years of age. In addition, it happens more in the winter months when hypothermia is more common.

What Are the Symptoms of Myxedema Coma?

A patient diagnosed with myxedema coma will already have symptoms of hypothyroidism for a long time. Apart from these, the patient will also develop the following symptoms:

• Altered mental status or mental impairment.

• Lethargy.

• Absent-mindedness.

• Confusion and non-responsiveness.

• Alopecia (hair loss).

• Low body temperature.

• Increased blood pressure, followed by decreased blood pressure.

• Slow heart rate.

• Delayed relaxation of deep tendon reflexes.

• Doughy skin.

• Decreased movement of the gut.

• Feeling bloated.

• Difficulty in breathing

• Swelling, especially of the face, legs, and tongue.

• Infertility issues.

• Constipation.

What Causes Myxedema Coma?

In the case of a myxedema coma, the body makes multiple changes to compensate for the thyroid hormone deficiency. But sometimes, numerous precipitating factors decompensate the patient to a myxedema coma despite all the physiological changes made by the body. Along with having a long-standing history of untreated hypothyroidism, the following factors act as stimulating factors:

• Infections such as pneumonia, influenza, urinary tract infection, etc.

• Stroke.

• Surgery.

• Trauma.

• Burns.

• Carbon dioxide retention.

• Decreased blood sugar level (hypoglycemia).

• Decreased body temperature (hypothermia)

• Medications include Amiodarone, Beta-blockers, anesthesia, Barbiturates, Diuretics, Lithium, etc.

How Is Myxedema Coma Diagnosed?

Several tests are done to confirm myxedema coma in a patient, and these tests may be blood tests, electrocardiogram (ECG), etc. Blood tests will show the following abnormalities:

1. Anemia.

2. Elevated creatinine.

3. Elevated creatine kinase level.

4. Elevated transaminases.

5. High carbon dioxide in the blood (hypercapnia).

6. High lipids, cholesterol, and triglyceride levels (hyperlipidemia).

7. Low blood sugar level (hypoglycemia).

8. Low concentration of sodium in the blood (hyponatremia).

9. Low oxygen concentration in the tissues (hypoxia).

10. A decrease in the number of white blood cells.

11. Respiratory acidosis.

Apart from these findings seen in the blood reports, ECG and other cardiovascular tests may show the following changes:

1. Elevated blood pressure (hypertension) in the early stage; is followed by low blood pressure (hypotension) in the later stage.

2. Low cardiac output.

3. Enlarged heart (cardiomegaly) may be seen on X-ray or other imaging tests.

4. Low heart rate (bradycardia).

5. Irregular heartbeat (arrhythmia).

6. Nonspecific ECG findings.

7. Bundle branch blocks or complete heart blocks.

How Is Myxedema Coma Treated?

Myxedema patients should be admitted to the emergency department or the intensive care unit as it is a life-threatening condition, and immediate medical aid should be given. Electrolyte abnormalities and extracellular fluid loss must be balanced with intravenous thyroid hormone replacement. Physical ventilation may also be required. Blood pressure should be stabilized, and cardiovascular criteria should be monitored. In hypothermia, the patient must be warm with blankets to prevent hypotension and cardiovascular collapse.

• Thyroid Hormone Replacement Therapy: Hypothyroidism is caused by the inability of the thyroid gland to produce an adequate amount of thyroid hormone. Myxedema coma is an extreme manifestation of hypothyroidism; therefore, any patient suspected of having a myxedema coma should be treated with thyroid hormone replacement therapy. In addition, this therapy must be administered carefully because it can cause a heart attack or irregular heartbeat if given in large doses. And if administered in low doses, there might be no significant positive effect on the treatment. So, it is crucial to adjust the amount given carefully. Thyroid hormone replacement therapy should start intravenously because gastrointestinal absorption may be impaired due to multiple complications caused by the condition.

• Use of Antibiotics: Since infection is the most common precipitating factor of myxedema coma, antibiotics to treat the infection should be an essential treatment modality. The cause of infection should be evaluated with the help of blood and urine examinations and imaging tests.

• Use of Steroids: In order to prevent the occurrence of any secondary hypothyroidism or hypopituitarism, steroids must be given to rule out any adrenal insufficiency. Hydrocortisone is usually the drug of choice, and it should be administered intravenously.

• Symptomatic Relief: Apart from these treatment modalities, symptomatic relief must also be given to the patient.

What Is the Prognosis of Myxedema Coma?

The prognosis of this condition cannot be determined because very few disease cases are reported and recorded. However, studies suggest that the mortality rate of this condition may be anything between 30 to 60 percent, and a poor prognosis is generally associated with geriatric patients (old age).

How Can Myxedema Coma Be Prevented?

Myxedema coma is a decompensated form of hypothyroidism, and it can be prevented if the patient manages hypothyroidism carefully with help from their physician. A patient with hypothyroidism should regularly visit their doctor for follow-up and get their hormone levels tested to check for sudden changes.

Conclusion:

Myxedema coma or hypothyroid coma is a rare yet fatal condition, and doctors should be careful while diagnosing and treating a patient with this condition. An accurate diagnosis can only be made with the help of proper medical history, physical examination to check for any signs and symptoms, and laboratory examinations. Although the mortality rate for this condition is very high, an accurate diagnosis followed by prompt and proper treatment can save someone’s life. However, the prognosis of the condition remains poor, and the mortality rate is between twenty to fifty percent. And if not treated immediately, many patients fail to survive.