Specific management aims to stop the peripheral effects of thyroid hormones and reduce hormone levels.
As the condition is rare, has a high mortality, and is part of a spectrum of disease, discussion with an endocrinologist is advised. Thyroid hormone levels do not define thyroid storm but normal levels should prompt a search for other diseases.
Strategies to stop peripheral effects
Propanolol 1 mg IV over 1 minute; if necessary repeat at 5-minute intervals; max. total dose 10 mg
or
Esmolol usually within range 50-200 micrograms/kg/minute
or
Metoprolol up to 5 mg at rate 1–2 mg/minute, repeated after 5 minutes if necessary, total dose 10-15 mg
Titrate until heart rate about 100 bpm. This helps with reducing rate related heart failure. Any betablocker can be used but only Propanolol has been shown to also prevent peripheral conversion of T4 to T3. The doses of beta blocker required may be higher than in other situations as their metabolism is increased in thyrotoxicosis.
If the patient cannot tolerate beta blockers – such as those with severe asthma,, rate control can be achieved with a calcium channel blocker such as:
Hydrocortisone 200 mg IV
or
Dexamethasone 2 mg IV
Steroids reduce the peripheral effects of thyroid hormones and will also treat associated hypoadrenalism if present.
Lowering circulating hormone levels
Two treatments with different actions are available. Both of these should be given however propylthiouracil should be given an hour before Lugol iodine.
In small doses iodine can lead to increased hormone production, nut in high doses (as given here) it is inhibitory and prevents its release. Propylthiouracil is given first to prevent initial iodine treatment increasing production.
Prevent synthesis
Propylthiouracil 150-300 mg PO QDS
Prevent release with iodine
Lugol iodine (5% iodine, potassium iodide 10%)10 drops daily PO.