What are the pre‑operative, intra‑operative, and post‑operative anesthesia considerations for a patient with known thyroid disease (hyperthyroidism or hypothyroidism) scheduled for surgery?

Anesthesia Management for Thyroid Disease Patients

For patients with thyroid disease undergoing surgery, the anesthesiologist must conduct a detailed pre-anesthetic evaluation focusing on airway anatomy, optimize thyroid function preoperatively when possible, and maintain vigilant postoperative monitoring for airway compromise and other complications. 1, 2

Preoperative Assessment and Optimization

Thyroid Function Status

• Hyperthyroid patients: Obtain thyroid function tests (TSH, FT4, T3) to quantify the degree of hyperthyroidism and optimize to euthyroid state before elective surgery to prevent thyroid storm. 1, 2
• Hypothyroid patients: Document thyroid status and achieve euthyroidism when possible before surgery, as hypothyroidism increases risk of intraoperative hypotension (61% vs 30% in controls), postoperative gastrointestinal complications (19% vs 1%), and neuropsychiatric complications (38% vs 18%). 3
• Exception: In patients with coronary artery disease requiring revascularization, address coronary blood flow first before initiating thyroid hormone therapy, as preoperative thyroid replacement could worsen myocardial ischemia. 4

Airway Evaluation

• The surgeon and anesthesiologist must communicate before the patient enters the operating room regarding any abnormal laryngeal findings that would require adjustments in anesthetic management. 5
• Specifically discuss: abnormal vocal fold mobility (laterality and degree), ability to visualize laryngeal inlet, altered laryngeal anatomy (rotation, compression, tumor invasion), hypopharyngeal crowding from goiter, and whether nerve monitoring will be used. 5
• Examine vocal fold mobility preoperatively if the patient has voice impairment, as 1-8% of thyroid disease patients have preexisting vocal fold paralysis (higher in malignancy). 5
• Prepare for difficult airway with fiberoptic intubation equipment available, particularly with large goiters causing tracheal deviation or compression. 1, 2

Special Populations

• Patients on chronic corticosteroids: Provide stress-dose coverage with hydrocortisone 100 mg IV at induction, followed by continuous infusion of 200 mg/24 hours while nil by mouth. 1, 2

Intraoperative Management

Intubation Technique

• General anesthesia with endotracheal intubation is typically required for thyroidectomy. 1, 2
• Avoid long-acting neuromuscular blocking agents if intraoperative nerve monitoring is planned, as they are absolutely contraindicated. 1, 6
• Consider deflating the endotracheal cuff during retractor placement and then gently reinflating to minimize recurrent laryngeal nerve (RLN) compression injury. 5
• Be aware that endotracheal tube cuff placement adjacent to the superior laryngeal or RLN may produce transient voice dysfunction lasting up to 24 hours. 5

Communication Protocol

• Use a pre-procedural checklist and briefing to review thyroid status, anticipated airway anatomy, and special monitoring requirements, as communication failures are a leading cause of medical errors. 5, 1, 2

Monitoring for Complications

• Hypothyroid patients: Anticipate increased risk of intraoperative hypotension during noncardiac surgery and heart failure during cardiac surgery (29% vs 6% in controls). 3
• Recognize that hypothyroid patients may not manifest fever with perioperative infection (35% vs 79% in controls). 3

Postoperative Management

Immediate Airway Assessment

• Assess voice function immediately postoperatively to detect RLN injury. 1, 2
• Monitor patients at least hourly for the first 6 hours postoperatively, as approximately 50% of hematomas occur within this timeframe. 1, 2
• Be prepared for possible airway compromise requiring urgent re-intubation, especially in patients with large goiters who may have tracheomalacia that becomes apparent only after gland removal. 5, 1

Complication Surveillance

• Use the DESATS protocol for early identification of complications: Difficulty swallowing, Early Warning Score elevation, Swelling, Anxiety, Tachypnea, and Stridor. 2
• Monitor for laryngeal edema, tracheomalacia, hypocalcemic tetany, and pneumothorax. 2, 7
• If suspected hematoma with airway compromise develops: Use the SCOOP approach at bedside (expose Skin, open skin to expose strap muscles, Open muscles to expose trachea, Pack wound) before attempting intubation. 2

Discharge Planning

• Avoid same-day discharge if any postoperative concerns arise. 1, 2
• After the initial 6-hour high-risk period, adjust observation frequency according to individual patient risk. 1

Key Pitfalls to Avoid

• Do not confuse hypothyroidism with euthyroid sick syndrome in critically ill surgical patients, as low thyroid hormones in nonthyroidal illness do not warrant replacement and may be harmful. 4
• Do not delay intubation if postoperative airway obstruction develops from bleeding or edema, but recognize that re-intubation may be difficult due to airway distortion. 5
• Do not assume normal temperature response to infection in hypothyroid patients, as they frequently fail to mount fever despite perioperative infection. 3