Myxedema Coma Diagnostic Score

• There are no objective, widely-accepted diagnostic criteria to define myxedema coma. 
• All clinical features associated with myxedema coma are nonspecific, and this scoring system is limited by the small number of patients from whom it was derived. 
• Therefore, it is important to prioritize clinical judgment and avoid overreliance on scoring. 
• Where available, consultation with an endocrinologist is warranted.

When thyroid laboratory results, clinical picture, and Myxedema Coma Diagnostic Score results are consistent with myxedema coma (>60 or >25 with a high degree of suspicion), prompt steroid and thyroid treatment are indicated.

• Prior to treatment, obtain a random cortisol level.
• Start IV hydrocortisone 100 mg every 8 hours until coexisting adrenal insufficiency is excluded.
• After steroids are administered, give an initial bolus of 200–400 mcg of IV levothyroxine, followed by 50–100 mcg IV daily until the patient is tolerating oral medication (reduce this dose in older adults, patients with lower body weight, or those with a cardiac history, given the risk of complications such as arrhythmias or myocardial infarction).
• Along with levothyroxine, some experts also recommend administering liothyronine 5–20 mcg IV once, followed by 2.5–10 mcg every 8 hours until the patient is stable and clinically improved (reduce this dose in older adults, patients with lower body weight, or those with a cardiac history). 
• One reasonable approach is to start with levothyroxine monotherapy and add liothyronine if there is clinical deterioration or persistent bradycardia.
• Monitor free T4 every 1–2 days to confirm treatment response. 
• For patients receiving liothyronine, also monitor total T3 every 1–2 days, ideally measured at the trough before the next liothyronine dose to assess steady-state exposure and avoid transient elevation.

• Take immediate steps to stabilize the patient: 
  
  • Secure the airway.
  • Administer IV fluids to address any hypovolemia.
  • Initiate passive rewarming for hypothermia.
  • Address electrolyte abnormalities.
  • Admit to the intensive care unit.
  • Identify and treat precipitating factors, such as infection. 
• In patients with thyroid laboratory findings and clinical features consistent with myxedema coma, start glucocorticoid therapy followed by thyroid medication.