Synopsis
Recognise clinical thyrotoxic decompensation, initiate coordinated critical-care treatment in the correct pharmacological sequence, and reverse the precipitating illness without delay.
- Storm is thyrotoxicosis with acute multisystem decompensation, commonly fever, severe tachycardia or atrial fibrillation, heart failure, agitation or delirium, and gastrointestinal or hepatic dysfunction.
- Free T4 and free T3 concentrations overlap with uncomplicated hyperthyroidism, so no biochemical cutoff can confirm or exclude the diagnosis.
- Infection, abrupt antithyroid withdrawal, surgery, childbirth, iodine load, diabetic ketoacidosis, myocardial infarction and stroke are recognised precipitants.
Key red flags
High fever, profuse sweating, dehydration and marked weakness in a thyrotoxic patient indicate excessive metabolic drive; hypothermia can occur very late in circulatory collapse.
Investigation priorities
Define organ failure and immediate response to resuscitation.
Management branches
Thyrotoxicosis accompanies fever and acute organ dysfunction.
- Call critical care, endocrinology and pharmacy; perform ABCDE, attach continuous ECG and invasive monitoring when required, and obtain wide-bore access.
- Support airway and ventilation, give cautious fluids guided by cardiac status, correct glucose and electrolytes, and use external cooling plus paracetamol rather than aspirin.
Key medicines
Carbimazole or propylthiouracil synthesis blockadeFor adult thyrotoxic crisis, give propylthiouracil 200 mg orally every 4–6 hours for the first 24 hours, then reduce as the crisis subsides. If carbimazole is chosen instead, use the exact current BNF or approved local storm regimen; do not infer dose equivalence.
Inorganic iodine after thionamideAfter the first thionamide dose, wait at least 1 hour, then give the pharmacy-verified local aqueous iodine or potassium iodide regimen. Record product, concentration and elemental iodine dose; never copy a volume or drop count between preparations.