Thyrotoxicosis (“Thyroid Storm”)

Etiology

• Progression of hyperthyroidism without adequate treatment
• Surgery
• Infection
• Infarction
• Trauma
• Acute iodine load (including radioactive iodine ablation)
• Childbirth

Presentation

• Agitation, delirium, psychosis, or coma
• Hyperthermia, tachycardia/arrhythmia, hypotension
• May have goiter, proptosis, tremors, or warm/sweaty skin

Diagnosis

• TSH <0.01 and T4 >4.0 in the setting of above findings

Management

• Airway, Breathing, Circulation (ABCs) first, always
• Beta-blockers for symptom control
  • Propranolol (this also decreases T3 production ₍₁₎ )
• Thionamide (Typically propylthiouracil, or PTU, but can use methimazole also)
• Treat precipitating factor
• Glucocorticoids: Reduce peripheral conversion of T4 to T3 and may have some benefit if the underlying precipitant of the thyrotoxicosis is autoimmune (i.e. Graves’ Disease)
• Cholestyramine: May have benefit by decreasing enterohepatic recycling of T3 and T4 by binding these hormones in the GI tract ₍₂₎
• Plasmapheresis: typically been reserved for failure of conventional management, but may have a role for early therapy for severe thyrotoxicosis, especially with neurologic symptoms ₍₃₎
• Radioactive Iodine Ablation (RAI): at least 1 hour after thionamide administration so that the iodine is not used as new substrate by the thyroid for thyroid hormone production _(4-5)

References

1. WM;, W. (n.d.). Propranolol and thyroid hormone metabolism. Retrieved December 30, 2020, from https://pubmed.ncbi.nlm.nih.gov/1688102/
2. KD;, S. (n.d.). Adjunctive cholestyramine therapy for thyrotoxicosis. Retrieved December 30, 2020, from https://pubmed.ncbi.nlm.nih.gov/8435884/
3. Muller C;Perrin P;Faller B;Richter S;Chantrel F;. (n.d.). Role of plasma exchange in the thyroid storm. Retrieved December 30, 2020, from https://pubmed.ncbi.nlm.nih.gov/22107688/
4. FQ;, S. (n.d.). Acute changes in thyroid function in patients treated with radioactive iodine. Retrieved December 30, 2020, from https://pubmed.ncbi.nlm.nih.gov/52005/
5. Burch HB, Solomon BL, Cooper DS, Ferguson P, Walpert N, Howard R. The effect of antithyroid drug pretreatment on acute changes in thyroid hormone levels after (131)I ablation for Graves’ disease. J Clin Endocrinol Metab. 2001 Jul;86(7):3016-21. doi: 10.1210/jcem.86.7.7639. PMID: 11443161.