Endocrine and metabolic emergencies

Thyroid storm and myxoedema coma

Reviewed Nov 2026·3 references
New· views rounded down, updated weekly

Thyroid storm: Burch-Wartofsky score ≥ 45 → β-blocker, thionamide (PTU preferred), iodine ≥ 1 h later, hydrocortisone, cooling and treatment of the trigger. Myxoedema coma: supportive care, hydrocortisone first, then thyroxine.

At the bedside

Timed steps
  1. 1

    Diagnose

    Storm

    Fever, tachycardia/AF, heart failure, agitation/delirium, GI/hepatic dysfunction with thyrotoxicosis. Burch-Wartofsky ≥ 45 highly suggestive; 25-44 impending storm.

  2. 2

    β-block

    Storm

    Propranolol 60-80 mg every 4 h (also reduces T4→T3); esmolol infusion if haemodynamically fragile.

  3. 3

    Block synthesis

    Storm

    PTU 500-1000 mg load then 250 mg every 4 h (or methimazole 60-80 mg/day).

  4. 4

    Block release

    Storm

    Iodine at least 1 h after the thionamide: SSKI 5 drops (0.25 mL) every 6 h or Lugol's iodine.

  5. 5

    Steroid + support

    Storm

    Hydrocortisone 300 mg IV load then 100 mg every 8 h; paracetamol and active cooling (avoid aspirin); fluids; treat infection. Plasmapheresis or urgent thyroidectomy if refractory.

  6. 6

    Recognise

    Myxoedema

    Hypothermia, coma, bradycardia, hypoventilation (hypercapnia), hyponatraemia, hypoglycaemia in long-standing hypothyroidism, often triggered by infection, cold, sedatives.

  7. 7

    Treat

    Myxoedema

    Hydrocortisone 100 mg IV 8-hourly until adrenal insufficiency excluded, then levothyroxine IV 200-400 mcg load and 1.6 mcg/kg/day × 0.75 IV (lower doses in elderly/cardiac); ventilate for hypercapnia; passive rewarming.

Thyroid storm

Propylthiouracil (PTU)

Oral/NG
Dose
500-1000 mg load, then 250 mg every 4 h

Thyroid storm

Hydrocortisone

IV
Dose
300 mg load, then 100 mg every 8 h

Myxoedema coma

Levothyroxine

IV
Dose
200-400 mcg load, then 1.6 mcg/kg/day × 0.75 IV daily
Worked example
70 kg, no cardiac disease: 300 mcg IV, then ~85 mcg IV daily

Burch-Wartofsky point scale (summary)

DomainPoints
Temperature 37.2-37.7 / 37.8-38.2 / 38.3-38.8 / 38.9-39.3 / 39.4-39.9 / ≥ 40 °C5 / 10 / 15 / 20 / 25 / 30
CNS: mild agitation / delirium, psychosis, lethargy / seizure or coma10 / 20 / 30
GI-hepatic: diarrhoea, vomiting, abdominal pain / unexplained jaundice10 / 20
Heart rate 99-109 / 110-119 / 120-129 / 130-139 / ≥ 1405 / 10 / 15 / 20 / 25
Heart failure: mild (oedema) / moderate (bibasal crackles) / severe (pulmonary oedema)5 / 10 / 15
Atrial fibrillation10
Precipitating event10

Score ≥ 45 highly suggestive of storm; 25-44 impending; < 25 unlikely.

Red flag · call your senior now
Thyroid storm with low-output heart failure: β-blockers can precipitate collapse; use esmolol with echo guidance.
Pitfall
Giving iodine before the thionamide (fuels hormone synthesis).
Pitfall
Full-dose thyroxine without steroid cover in myxoedema coma.
Pearl
Free T4/T3 levels do not separate storm from uncomplicated thyrotoxicosis; the diagnosis is clinical.

References

  1. 1

    Ross DS, Burch HB, Cooper DS, et al. 2016 American Thyroid Association guidelines for diagnosis and management of hyperthyroidism and other causes of thyrotoxicosis. Thyroid. 2016;26(10):1343-1421

  2. 2

    Jonklaas J, Bianco AC, Bauer AJ, et al. Guidelines for the treatment of hypothyroidism: prepared by the American Thyroid Association task force on thyroid hormone replacement. Thyroid. 2014;24(12):1670-1751

  3. 3

    Burch HB, Wartofsky L. Life-threatening thyrotoxicosis. Thyroid storm. Endocrinol Metab Clin North Am. 1993;22(2):263-277

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