Myxedema Coma most commonly presents with only a decline in mental status (may be subtle) and rarely presents as coma or extremity edema. Hypothyroid patients typically have a history of fatigue, weight gain/puffiness, constipation, and cold intolerance. Consider hypothyroidism in any patient presenting with hyponatremia which may be associated with a low serum osmolality. The typical patient is a woman (80% of cases) and older than 60 years. Interestingly the vast majority of myxedema coma cases occur in the winter months. All patients must be assumed to have an infection. The patient’s temperature is usually less than 35.5°C (95.9°F). Creatine kinase levels are sometimes elevated (skeletal fraction) and EKG changes consisting of non specific ST/T changes on EKG may confuse the picture. Myocardial infarction must be ruled out.
- T4 200 to 500 mcg IV (>500 mcg/d is associated with higher mortality). Make sure to have the patient on cardiac monitoring
- Use passive rewarming as the use of warming blankets can result in peripheral dilatation leading to hypotension and cardiovascular collapse
- Empiric antibiotics are commonly recommended while awaiting cultures (infection is present in 35% of patients).
- Hydrocortisone 100 mcg IV every eight hours should be given to prevent adrenal insufficiency
- Hyponatremia will usually resolve secondary to treatment