Perioperative Management of Hypothyroidism

Preoperative Assessment and Optimization

Delay elective surgery until euthyroidism is achieved whenever feasible, as untreated hypothyroidism increases risk of heart failure, gastrointestinal complications, and prolonged ventilation requirements in patients with hypothyroidism, according to the American Heart Association 1

Avoid etomidate for induction if possible, as it suppresses cortisol production, and maintain high clinical suspicion for relative adrenal insufficiency in patients undergoing surgery, as recommended by the American Society of Anesthesiologists 2
Patients with hypothyroidism undergoing CABG have higher incidence of postoperative heart failure and gastrointestinal complications, and subclinical hypothyroidism may increase risk of postoperative atrial fibrillation, particularly with TSH ≥10 mIU/L, according to the American Heart Association 1

No stress-dose adjustment is needed for levothyroxine, unlike glucocorticoids, as stated by the American Society of Anesthesiologists 3 and 2
Hypothyroidism is contraindicated for treatment until adrenal insufficiency is corrected, as thyroid hormone accelerates cortisol clearance and can precipitate adrenal crisis, according to the Endocrine Society, although the specific guideline is from Praxis Medical Insights, an alternative source is not provided 4