Perioperative Management of Total Thyroidectomy

I. PREOPERATIVE MANAGEMENT

1. Biochemical and Imaging Workup

• Thyroid function tests (TSH, free T3, free T4) to establish baseline and guide optimization
• Serum calcium - check in all patients at risk for concurrent primary hyperparathyroidism (e.g., MEN2A), and as a baseline
• Neck ultrasound - standard imaging; CT/MRI for large goiters or substernal extension
• Fine needle aspiration (FNA) cytology for nodular disease or suspected malignancy
• Serum PTH - baseline useful for later comparison

2. Optimization of Thyroid Function

• For hyperthyroidism (especially Graves' disease):
  • Thionamides: methimazole or propylthiouracil (PTU) to block hormone synthesis; PTU also blocks peripheral T4-to-T3 conversion
  • Beta-blockade: propranolol (non-selective preferred) to control tachycardia, hypertension, and tremor
  • Lugol's solution (5% iodine + 10% KI, 5-7 drops three times daily) or potassium iodide (1-2 drops three times daily) for 7-10 days before surgery - inhibits iodine organification, reduces thyroid vascularity and blood flow, and decreases intraoperative hemorrhage
  • In patients with severe cardiovascular comorbidity, thyroid storm risk is highest; optimization is non-negotiable
  • Glucocorticoids may also be used in severe hyperthyroidism preoperatively
• For euthyroid patients (e.g., nodular goiter, well-differentiated thyroid cancer): No specific thyroid-directed preoperative medication needed

3. Voice and Laryngeal Assessment

• All patients: thorough history of voice changes, prior cervical/chest surgery, dysphagia
• AAES Guidelines: all patients should have noninvasive preoperative voice assessment
• Formal laryngoscopy is indicated for: preoperative voice abnormalities, history of prior cervical or upper chest surgery, thyroid cancer with posterior extrathyroidal extension, or bulky nodal metastases
• Transcutaneous laryngeal ultrasound is an emerging noninvasive alternative with 93-100% sensitivity for vocal cord paralysis detection; less reliable in older or male patients due to thyroid cartilage calcification
• Pre-existing vocal cord dysfunction occurs in up to 3.5% of benign disease and up to 8% of thyroid cancer patients - documenting this is critical for medicolegal and surgical planning

4. Airway Assessment

• Assess for tracheal deviation or compression (relevant in large goiters, substernal extension)
• CT neck/thorax may be needed for substernal extension to plan for potential difficult airway or tracheomalacia
• Discuss potential awake fiberoptic intubation if airway compromise is anticipated

5. Anticoagulation and Medications

• Anticoagulants should be managed per standard perioperative protocols (bridging vs. cessation based on thromboembolic risk)
• NSAIDs/antiplatelet agents adjusted per institutional protocol given risk of neck hematoma

II. INTRAOPERATIVE MANAGEMENT

1. Anesthesia and Positioning

• General endotracheal anesthesia is standard
• If intraoperative neuromonitoring (IONM) is planned, a neuromonitoring-specific ETT with surface contact electrodes for the vocal cords is used (e.g., NIM tube)
• Patient positioned supine, both arms tucked, neck extended with a shoulder roll to expose the anterior neck
• Back/head of the bed elevated to reduce venous engorgement

2. Intraoperative Neuromonitoring (IONM)

1. Initial vagal nerve stimulation to confirm intact baseline RLN function and correct electrode position
2. RLN identification and stimulation before dissection (R1/L1 signals)
3. Dissection with continuous awareness of signal integrity
4. Post-dissection RLN stimulation to confirm preserved function (R2/L2 signals)
5. Final vagal nerve stimulation to confirm intact bilateral function before closure

3. Parathyroid Gland Preservation

• Meticulous dissection to identify all four parathyroid glands and preserve their blood supply
• Near-infrared (NIR) autofluorescence imaging is an emerging technology for intraoperative parathyroid identification (mixed evidence on whether it reduces hypoparathyroidism rates)
• If a parathyroid is inadvertently removed or devascularized: it should be minced and autotransplanted into the sternocleidomastoid muscle (confirmed first by frozen section or intraoperative PTH aspiration)
• All specimens should be inspected for inadvertent parathyroid tissue

4. Energy Devices and Hemostasis

• Energy sealing devices (bipolar radiofrequency e.g., LigaSure; ultrasonic e.g., Harmonic) are widely used for ligation of superior pole vessels - associated with equivalent outcomes to clamp-tie methods and improved operative times
• Caution is required near the RLN and parathyroids due to radial thermal spread
• Topical hemostatic agents (oxidized cellulose, fibrin sealants) reduce drain output and hospital stay but do not significantly reduce hematoma rates

5. Cardiovascular Monitoring

• In patients with Graves' disease or incompletely treated hyperthyroidism: anticipate hemodynamic instability (hypertension, tachycardia, arrhythmias)
• Induction of anesthesia may require higher inhaled anesthetic concentrations due to elevated cardiac output
• Manipulation of the carotid sinus can cause bradycardia, arrhythmias, or sinus arrest - carotid sheath infiltration with local anesthetic mitigates this

III. POSTOPERATIVE MANAGEMENT

1. Airway Monitoring

• Incidence: 0.1-1.1% of thyroidectomies
• Risk factors: male sex, advanced age, bilateral operation, Graves' disease, anticoagulant use
• The vast majority occur within the first 6-24 hours
• Presentation: pain, swelling, ecchymosis, oozing at wound, stridor, respiratory distress
• Management: if hematoma with airway compromise - immediate bedside wound opening (all three layers: skin, platysma, strap muscles) for decompression; then return to OR for formal re-exploration and hemostasis
• Wound opening equipment should be at the bedside at all times in the immediate postoperative period

2. Calcium and PTH Monitoring - Hypoparathyroidism

• Neurologic: circumoral paresthesias (earliest), light-headedness, anxiety, Chvostek sign (facial nerve tapping), Trousseau sign (carpal spasm with BP cuff inflation), laryngospasm, seizures
• Musculoskeletal: tetany, cramps, involuntary twitching
• Cardiovascular: prolonged QT interval, T-wave changes, arrhythmias, tachycardia, hypotension

• Check serum calcium and PTH at 4-6 hours postoperatively
• Intact PTH < 10 pg/mL at 4-6 hours is predictive of hypocalcemia and guides prophylactic supplementation
• Daily calcium levels until stable and on oral supplementation

• Asymptomatic/mild: oral calcium carbonate (1-2g elemental Ca 3x/day) ± calcitriol (0.25-0.5 mcg twice daily)
• Symptomatic or severe (Ca < 1.9 mmol/L): IV calcium gluconate (1-2g infused slowly); this is a medical emergency
• High-risk patients (Graves' disease, pediatric, bilateral neck dissection): prophylactic calcium ± calcitriol started preoperatively or immediately postoperatively

3. Vocal Cord Assessment

• Postoperative voice assessment in all patients
• Laryngoscopy if new hoarseness, voice change, or stridor is noted
• Unilateral RLN injury: hoarse, breathy voice, dysphagia, aspiration
  • Temporary injury rate: 4-10%; permanent: 0.5-2%
• Bilateral RLN injury: stridor, respiratory distress, may require tracheostomy
• EBSLN injury: vocal fatigue, loss of high pitch, decreased projection
• Early ENT/laryngology referral for voice therapy or medialization procedures if permanent injury confirmed

4. Thyroid Hormone Replacement

• Following total thyroidectomy, the patient is rendered permanently hypothyroid
• Levothyroxine (LT4) should be started postoperatively:
  • Typical starting dose: 1.6 mcg/kg/day for benign disease
  • For thyroid cancer: higher suppressive doses targeting TSH < 0.1-0.5 mIU/L (low-risk DTC) or TSH < 0.1 mIU/L (high-risk) depending on risk stratification
• TSH checked at 6-8 weeks post-operatively to adjust dose
• Calcium absorption is affected by LT4 timing - take LT4 on empty stomach, calcium supplements 4 hours apart

5. Management of Thyroid Storm (Perioperative)

1. Block synthesis: PTU 500-1000 mg loading dose, then 250 mg every 4h (preferred over methimazole as it also blocks T4-to-T3 conversion) - OR methimazole 20-30 mg every 4-6h
2. Block release (1 hour after thionamide): Lugol's solution or SSKI (to prevent oxidation of iodide to iodine)
3. Block peripheral conversion and adrenergic effects: propranolol IV/oral; hydrocortisone 100 mg IV every 8h (also provides adrenal protection)
4. Supportive: antipyretics (avoid aspirin - displaces T4 from TBG), IV fluids, cooling blankets, ICU monitoring
5. Bile acid sequestrants (cholestyramine) to reduce enterohepatic recycling
6. Definitive treatment (once stabilized): RAI or thyroidectomy

6. Drain Management

• Drains are not routinely required for uncomplicated thyroidectomy
• If placed, typically removed within 24-48 hours when output < 30 mL/day
• Early discharge (same-day or 23-hour stay) is increasingly practiced for low-risk total thyroidectomies performed by high-volume surgeons

IV. SPECIAL CONSIDERATIONS

Surgeon Volume

Reoperative Surgery

Pediatric Patients

Outpatient Thyroidectomy

Summary Table: Key Perioperative Steps