Thyroid disease, thyroid storm and thyroidectomy
Stem
A 36-year-old woman, 58 kg, with Graves disease is scheduled for elective total thyroidectomy next week. She stopped methimazole a month ago because of a rash. Today her heart rate is 112 in sinus rhythm, she has a tremor and has lost weight, and free T4 is three times the upper limit of normal. She has a large goiter; CT shows mild tracheal deviation without narrowing, and she has no stridor.
Question
Is she ready for surgery, and how will you prepare her?
Ideal answer
HeadlineShe is not ready: overtly thyrotoxic, and operating now risks thyroid storm. I postpone and, with endocrinology, make her euthyroid with an antithyroid drug, with or without beta-blockade.1
- A different antithyroid drug, because of the methimazole rash; if none is tolerated, rapid preparation: beta-blockade, potassium iodide, glucocorticoids, possibly cholestyramine, with an experienced surgeon and anesthesiologist.1
- Iodide in the immediate preoperative period, typically SSKI 1–2 drops or Lugol's 5–7 drops three times a day for 10 days, which blocks hormone release.1
- Beta-blocker titrated until resting tachycardia and tremor are controlled.
- Calcium and vitamin D checked and repleted now, because that lowers postoperative hypocalcemia.1
- Airway: deviation without compression usually intubates normally; I review the CT, ask about positional dyspnea, and have a videolaryngoscope and smaller tubes ready.
Watch for: neck hematoma, recurrent laryngeal nerve injury, hypocalcemia, early postoperative storm.
Breaking down the answer
- Euthyroid first — surgery, anesthesia and gland manipulation can all precipitate storm, and pretreatment prevents it.1 Delaying an elective case shows judgment.
- Iodide after the thionamide — in storm iodide starts an hour after the antithyroid drug, so it does not fuel new hormone synthesis.1 Steroids block T4-to-T3 conversion and cover relative adrenal insufficiency.1
- Plan B is for intolerance or urgency — the guideline's route when she cannot be made euthyroid or the operation cannot wait.1
- Calcium is predictable — low intact PTH (below 10–15 pg/mL) after surgery predicts symptomatic hypocalcemia.1
- Complication rates — with a high-volume surgeon, permanent hypoparathyroidism under 2%, permanent recurrent laryngeal nerve injury under 1%, bleeding needing reoperation 0.3–0.7%.1
- The opposite emergency: myxedema coma — altered mentation, hypothermia, hypoventilation, hypotension, bradycardia, hyponatremia, hypoglycemia, often after infection, cold or sedatives; mortality 20–50%.2
- Myxedema under anesthesia — a maximally vasoconstricted, volume-depleted circulation and hypoventilation: cautious crystalloid, stress-dose hydrocortisone with the first IV levothyroxine,3 liothyronine if no improvement in 24 hours; I intubate early rather than sedate, because sedatives precipitate the coma.2
Follow-up question
Ten days later, after propranolol, iodide and dexamethasone, she comes to the OR. Forty minutes into the dissection her temperature is 39.4 °C, heart rate 148 in new atrial fibrillation, blood pressure 92/50, and end-tidal CO2 has risen modestly.
What do you do?
Follow-up answer
HeadlineThyroid storm from a manipulated thyrotoxic gland, with malignant hyperthermia on the differential. I tell the surgeon to finish quickly and call for help.
Marked rigidity or a rapidly climbing CO2 would push me to dantrolene. I control the rate with an esmolol infusion titrated against her pressure; propranolol is the oral choice, used with caution in heart failure or shock.1,4 Propylthiouracil 500–1000 mg by nasogastric tube, with endocrinology weighing her methimazole rash; iodide continued; hydrocortisone 300 mg IV.1 Acetaminophen, cooling blankets, volume, ICU.1 I reassess heart rate, temperature and lactate, because storm still carries 8–25% mortality.1
Pitfalls that cost points
- Excluding myxedema coma on a normal TSH: TSH can be low or normal in central hypothyroidism or nonthyroidal illness.2
- Giving iodide before the thionamide in storm.
- Aggressive peripheral rewarming in myxedema coma: vasodilation can precipitate shock.2
Rapid-fire
Q: What Burch–Wartofsky score indicates storm? A: 45 or more; 25–44 is impending storm, and below 25 makes storm unlikely.1
Q: Why is PTU preferred over methimazole in storm? A: It also blocks T4-to-T3 conversion; T3 fell about 45% in the first 24 hours with PTU versus 10–15% with methimazole in one study.1
Q: What is the SSKI dose in storm? A: 5 drops (250 mg) orally every 6 hours, starting an hour after the thionamide.1
Q: What do you do first for a neck hematoma with stridor after thyroidectomy? A: Open the wound at the bedside to decompress the airway, then secure it.
Q: How is myxedema coma treated? A: Levothyroxine 200–400 mcg IV (100–200 if old or cardiac), then 1.6 mcg/kg daily;3,2 hydrocortisone 100 mg IV with the first dose, then 50 mg 6-hourly until adrenal insufficiency is excluded.3,5
Q: When can she go home with respect to calcium? A: When asymptomatic, with albumin-corrected calcium of 8.0 mg/dL or more and not falling over 24 hours.1
Numbers to know
| Item | Value |
|---|---|
| Preoperative SSKI (Graves) | 1–2 drops three times daily for 10 days1 |
| PTU in storm | 500–1000 mg load, then 250 mg every 4 h1 |
| Propranolol in storm | 60–80 mg every 4 h1 |
| Hydrocortisone in storm | 300 mg IV, then 100 mg every 8 h1 |
| Burch–Wartofsky | ≥45 storm, 25–44 impending1 |
| Storm mortality | 8–25%1 |
| Myxedema coma levothyroxine | 200–400 mcg IV, then 1.6 mcg/kg daily3,2 |
Links
- Anticipated difficult airway and the ASA algorithm, Awake fiberoptic intubation: topicalization and sedation, Malignant hyperthermia, Adrenal insufficiency and stress-dose steroids, Calcium disorders and parathyroid surgery
- 2016 ATA Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis
Sources
- 1.2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis · American Thyroid Association (Thyroid 2016;26:1343–1421), 2016 · nursing.duke.eduRoss et al. Recommendations 24–31 (thyroidectomy for Graves disease), 34–35 and Tables 6–7 (thyroid storm).
- 2.Myxedema Coma (Severe Hypothyroidism) · Endotext (NCBI Bookshelf), Wiersinga WM, 2026 · endotext.orgLast updated 2026-01-09; recognition, T4/T3 dosing, hydrocortisone, no peripheral rewarming, mortality 20-50%.
- 3.Management of endocrine emergencies: joint consensus statement for management of myxoedema coma · European Thyroid Journal (Taylor et al.; endorsed by ETA, BTA, Society for Endocrinology), 2026 · europepmc.orgLevothyroxine IV load 200-400 mcg (100-200 mcg if smaller, older or cardiac); prompt thyroid hormone with early empiric stress-dose glucocorticoid; hydrocortisone 100 mg IV stat then 50 mg four times daily in all patients until the adrenal axis is cleared. Endotext (2026) gives 300-500 mcg; the consensus figure is used.
- 4.Thyroid Storm (Vanderbilt Internal Medicine Residency Handbook) · Vanderbilt University Medical Center, 2026 · vimbook.vumc.org
- 5.Hypothyroidism and Myxedema (UCSF Hospital Handbook) · UCSF Hospital Handbook · hospitalhandbook.ucsf.eduIV load 200-400 mcg (lower in elderly or cardiac patients); hydrocortisone 50-100 mg q6-8h until adrenal insufficiency ruled out.
Facts on this page were checked against these sources on Oct 15, 2026. Guidelines change; confirm doses against current institutional protocols.