Adrenal and Thyroid Disorder Emergencies

Definition/Etiology:

• Thyroid Storm – A hypermetabolic state associated with hyperthyroidism. Usually secondary to Graves’ Disease. Can be cause by stress, drug reactions, surgery, trauma, MI, infection, DKA and embolism

• Myxedema (hypothyroid) Coma: Usually results from stress in patients with preexisting hypothyroidism. Can also be caused by infection, heart failure, medications, trauma, exposure to cold.

• Acute Adrenal Insufficiency: Result of a sudden decrease in cortisol and aldosterone levels. Primary occurs in those with preexisting insufficiency (Addison disease). Secondary is much more common. Long term glucocorticoid use causes adrenal suppression, reducing cortisol production. When we stop the steroids, there is a decrease in cortisol, and we go into an adrenal crisis.
  • Can be caused by stress, infection, burns, trauma, damage to the adrenals or pituitary, abrupt withdrawal of the glucocorticoids, head injuries with pituitary involvement.

Pathophysiology:

• The pathophysiological basis for precipitation of thyroid storm in patients with thyrotoxicosis is not clear. But, a precipitating factor, as mentioned above, is always required to cause thyroid storm. I’ll let you guys dive into the hypothesis, but it’s not terribly relevant for the exam.

• Myxedema coma occurs as a result of long-standing, undiagnosed, or undertreated hypothyroidism and is usually precipitated by a systemic illness. Myxedema coma can result from any of the causes of hypothyroidism, most commonly chronic autoimmune thyroiditis. It can also occur in patients who had thyroidectomy or underwent radioactive iodine therapy for hyperthyroidism. Rare causes may include secondary hypothyroidism and medications such as lithium and amiodarone.

• Secondary adrenocortical insufficiency occurs when exogenous steroids have suppressed the hypothalamic-pituitary-adrenal (HPA) axis. Too rapid withdrawal of exogenous steroids may precipitate adrenal crisis, or sudden stress may induce cortisol requirements in excess of the adrenal glands’ ability to respond immediately. In acute illness, a normal cortisol level may actually reflect adrenal insufficiency because the cortisol level should be quite elevated.

Collaborative Management:

• Thyroid storm: Needs to be identified and treated quickly. Can progress to cardiac death in as little as 2 hours. Untreated it carries a 90% mortality rate! Care involves identifying and treating the underlying cause, reducing the thyroid hormone level, and managing systemic manifestations like hyperthermia and dysrhythmias.

• Give acetaminophen for fever Beta-blocker to counteract sympathetic hyperstimulation. Inderal IV is common but esmolol can also be used

• Antithyroid drugs:
  • Propylthiouracil (PTU)
  • Tapazole
  • Iodine
  • Reserpine
  • Guanethidine
  • Dexamethasone

• Maintain fluid and caloric intake for increased metabolic demands.

Myxedema:

• Airway management as needed
• Gentle rehydration and sodium replacement
• Passive rewarming
• IV thyroid hormone replacement (levothyroxine)
• Glucocorticoids (for possible coexisting adrenal insufficiency…see everything ties together!)

With both thyroid emergencies, Let’s get an EKG and lab work is needed. The basics of course, CMC, CMP, Coags, and lets maybe not forget a thyroid panel here…i mean we are treating the thyroid. Might be nice to see where our numbers are.

AAI:

• Fluids
• Electrolyte stabilization
• Hydrocortisone IV
• Dexamethasone

Evaluation | Patient Monitoring | Education:

• For all of these conditions our goal is to get the patient back to baseline levels. As we treat, we need to monitor the appropriate serum levels of the condition we are treating, thyroid levels, cortisol levels, and such.
• We can monitor our patients appropriately, are there symptoms subsiding? Have we corrected or treated the underlying conditions?

Linchpins: (Key Points)

• The cause – find and treat it
• Up or down – add or remove the right hormone
• Labs labs labs – these are going to be your gold!