First Step in Management of Myxoedema Coma
The first step in managing myxoedema coma is immediate hospitalization in an intensive care unit with aggressive supportive care focused on maintaining airway, breathing, and circulation—including intubation and mechanical ventilation if the Glasgow Coma Score is ≤8. 1
Initial Stabilization Takes Priority Over Hormone Replacement
The critical initial actions are:
- Secure the airway immediately if the patient has altered consciousness (Glasgow Coma Score ≤8), as respiratory failure from decreased respiratory drive is common 1
- Correct hypoglycemia emergently if present, as this can be life-threatening and must be addressed before other interventions 1
- Administer hydrocortisone 100 mg IV every 8 hours until adrenal insufficiency is ruled out, as concurrent adrenal crisis can be precipitated by thyroid hormone replacement 1, 2
Why Supportive Care Precedes Thyroid Hormone Therapy
The evidence strongly supports that stabilization must occur before or simultaneously with thyroid hormone administration. Myxoedema coma patients typically present with:
- Hypothermia, hyponatremia, hypercarbia, and severe hypoxemia 3, 4
- Respiratory acidosis with depression of respiratory center responsiveness 3
- Cardiovascular instability requiring pressors 4
Starting thyroid hormone replacement without addressing adrenal insufficiency can precipitate adrenal crisis and death 1, 2. The metabolism increases faster than adrenocortical activity when thyroid hormones are given, making glucocorticoid coverage essential 2.
Thyroid Hormone Replacement Follows Stabilization
Once the patient is stabilized with airway management, glucose correction, and glucocorticoid coverage:
- Intravenous levothyroxine is the standard treatment for myxoedema coma 5
- Continue IV therapy for 3-10 days until the patient can take oral medication and normal gastrointestinal absorption is restored 5
- In cases of intestinal atony or ileus, IV administration is mandatory as oral absorption fails 3
Common Pitfalls to Avoid
- Never start thyroid hormone replacement before glucocorticoid coverage in severe, prolonged hypothyroidism, as this can precipitate fatal adrenal crisis 1, 2
- Do not rely on oral thyroid hormone initially, as these critically ill patients often have impaired gastrointestinal absorption and may have ileus 3, 6
- Monitor for cardiovascular complications, as elderly patients and those with occult cardiac disease are at high risk for myocardial infarction when thyroid hormones are administered 7