Thyroid Storm

Introduction

Thyroid storm , also known as thyroid crisis, is an rare form thyrotoxicosis in an extreme fashion
The mortality that has been published has ranged from 20-100%, especially if prompt treatment isn't initiated
Thyroid storm often occurs in people with Graves disease who have stopped medication or whose underlying condition is undiagnosed
The pathophysiology is characterized by adrenergic hyperactivity either by increased release of thyroid hormones (with or without increased synthesis) or increased receptor sensitivity.
Precipitants of Thyroid Storm include Infection, trauma, surgery, DKA, withdrawal of anti-thyroid medication, or radioactive iodine therapy
Diagnosis can be difficult due to the disease mimicking other disease states such as withdrawal syndromes and sepsis

Properties	Propranolol/ Esmolol	Methimazole/ Propylthiouracel (PTU)	SSKI	Hydrocortisone
Dose	Propranolol: IV 0.5-1 mg over 10 min or PO: 60-80 mg q4h Esmolol IV: 500 mcg/kg bolus then 50-200 mcg/kg/min infusion	Methimazole 60-80 mg in divded dose PTU: 500-1000 mg load then 250 mg q4h	5 drops PO q6h	IV: 300 mg load then 100 mg q8h
Administration	Propranolol IV: via slow IV push ~10 min Esmolol: Bolus and continuous infusion	PO	Place drops in water or juice with administration delayed for at least one hour after initiation of methimazole or PTU therapy	Via IV push
Formulation	Propranolol: PO/IV Esmolol: IV	PO	PO	IV/PO
Adverse Effects	Bradycardia, hypotension	PTU: black box warning for severe and/or life-threatening hepatotoxicity issued by FDA in 2010 Methimazole: not preferred in pregnancy	If not given after thionamide can serve as a substrate for thyroid hormone synthesis and exacerbate thyroid storm	Further hyperglycemia
Comments	Propranolol is only beta blocker that has been documented to Inhibit peripheral conversion of T4 to T3 Propranolol is preferred but may be difficult to access in an emergency, Esmolol may be good alt until propanol sent from MIP	Pregnancy considerations: PTU is generally preferred over MMI	Iodine solutions are not interchangeable If contraindication to giving iodine (for example, hypersensitivity to iodine), an alternative like lithium 300mg q8h can be used	Can use dexamethasone 4mg q6h as alternative

Drug	Purpose
Iodide: Lugol solution, Potassium Iodine (SSKI), and lithium	Used to prevent the release of pre-formed thyroid hormone from the thyroid gland
Thioureas: Methimazole/Propylthiouracel (PTU)	Inhibit thyroid peroxidase, an enzyme involved in the production of T3 and T4 through the iodination of tyrosine residues on thyroglobulin
Beta Blocker: Propranolol and Esmolol	Blocks β-adrenergic receptors to allow for effective treatment of systemic effects, such as tremor, tachycardia, agitation, fever, diaphoresis, psychosis Propranolol also blocker peripheral conversion of T4T3
Steroids: Hydrocortisone and Dexamethasone	Inhibition of peripheral conversion of T4 to T3 and treat relative adrenal insufficiency.

There is very limited evidence for the use of these agents that are limited to case reports and data dating back to 1970s-90.

A great review article is Thyroid emergencies written by Joanna Klubo-Gwiezdzinska in the references below.

However, these drugs are recommended in the 2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and other causes of Thyrotoxicosis.

Thiessen MEW. Thyroid and Adrenal Disorders in: Walls, R. Hockberge RS, Gausche-Hill M. (2018). Rosen's emergency

medicine: Concepts and clinical practice (9th ed.). Philadelphia, PA: Elsevier/Saunders.

Klubo-Gwiezdzinska J, Wartofsky L. Thyroid emergencies. Med Clin North Am. 2012 Mar;96(2):385-403.
Devereaux D and Tewelde SZ. Hyperthyroidism and thyrotoxicosis. Emerg Med Clin North Am. 2014 May;32(2):277-92.
Busti AJ, Herrington JD, Nuzum D. " Why Propranolol Is Preferred to Other Beta-Blockers in Thyrotoxicosis or Thyroid Storm", Evidence Based Consult blog, December 21, 2018. Available at: https://www.ebmconsult.com/articles/propranolol- preferred-thyroid-storm-thyrotoxicosis

Micromedex [Electronic version].Greenwood Village, CO: Truven Health Analytics. Retrieved September 6, 2018, from
http://www.micromedexsolutions.com/
Idrose A. Hyperthyroidism. In: Tintinalli JE, Stapczynski J, Ma O, Yealy DM, Meckler GD, Cline DM. eds. Tintinalli's Emergency Medicine: A
Comprehensive Study Guide, 8e New York, NY: McGraw-Hill; 2016.
Bahn RS, et al; American Thyroid Association; American Association of Clinical Endocrinologists. Hyperthyroidism and other causes of thyrotoxicosis: management guidelines of the American Thyroid Association and American Association of Clinical Endocrinologists. Endocr
Pract 17:456-520, 2011. Erratum in: Endocr Pract 19:384, 2013.
Thiessen MEW. Thyroid and Adrenal Disorders in: Walls, R. Hockberge RS, Gausche-Hill M. (2018). Rosen's emergency medicine: Concepts and clinical practice (9th ed.). Philadelphia, PA: Elsevier/Saunders.
Klubo-Gwiezdzinska J, Wartofsky L. Thyroid emergencies. Med Clin North Am. 2012 Mar;96(2):385-403.
Devereaux D and Tewelde SZ. Hyperthyroidism and thyrotoxicosis. Emerg Med Clin North Am. 2014 May;32(2):277-92.
Busti AJ, Herrington JD, Nuzum D. " Why Propranolol Is Preferred to Other Beta-Blockers in Thyrotoxicosis or Thyroid Storm",
Evidence Based Consult blog, December 21, 2018. Available at: https://www.ebmconsult.com/articles/propranolol- preferred-thyroid-storm-thyrotoxicosis