Perioperative Management of Hypothyroid Patients

Preoperative Considerations

The American Society of Anesthesiologists recommends avoiding etomidate for induction in hypothyroid patients, as it suppresses cortisol production, though single-dose effects remain controversial 1, 2
The Endocrine Society suggests that preoperative thyroid treatment does not eliminate the risk of complications, and clinical and chemical features of hypothyroidism do not reliably predict which patients are at highest risk for perioperative complications 4

The American Heart Association recommends monitoring cardiovascular function closely, particularly during cardiac surgery where heart failure risk is elevated in hypothyroid patients 2
Anesthesiologists should anticipate and prepare for intraoperative hypotension, have vasopressors readily available, and consider invasive blood pressure monitoring for major procedures 1, 2

The Society of Critical Care Medicine advises maintaining high suspicion for infection despite absent fever, as hypothyroid patients have blunted febrile responses 3, 2
Ensure adequate stress-dose corticosteroids if the patient has been on chronic corticosteroid therapy, such as hydrocortisone 100 mg IV at induction, followed by 200 mg/24h continuous infusion 3, 2, 4

The American Thyroid Association notes that low thyroid hormones in acutely ill surgical patients may represent euthyroid sick syndrome rather than true hypothyroidism, and in euthyroid sick syndrome, FT4 is typically in the lower normal range, whereas in hypothyroidism with TSH of 45, FT4 would be clearly low 5