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    Thyroid Storm – Diagnosis and Treatment

    Critical Care / Resuscitation, Metabolic / Endocrine

    Last Updated Dec 16, 2022
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    By John Ward, Jethro Moneo

    First 5 Minutes

    • Early recognition essential in initiating disease-specific life-saving treatments for this high mortality condition
    • Thyroid storm can mimic other conditions (ex. psychosis, meningitis, hyperthermia, sepsis, cardiogenic shock) and should be considered in all patients with fever, altered mental status and signs of sympathetic over-activity.
    • A low threshold to draw thyroid labs is essential in early diagnosis and treatment initiation.


    • Thyroid storm is a rare, life-threatening condition characterized by severe/life-threatening manifestations of thyrotoxicosis
      • Often inappropriately applied to un/undertreated hyperthyroidism but clinically differentiated by severity of symptoms/life threat
    • Usually precipitated by acute event, though can result from longstanding untreated hyperthyroidism.
      • General stressors: infection, surgery, trauma, PE/MI/Stroke, labor, preeclampsia, DKA, hypoglycemia
      • Thyroid-related: thyroid surgery, radioiodine therapy, irregular use or discontinuation of thyroid or antithyroid drugs, acute iodine load (amiodarone, contrast dye), checkpoint inhibitors, ASA intoxication
      • 30% have no identifiable precipitant.
    • Mortality is high – up to 10-50% with treatment and up to 100% without treatment.
    • Treatment must be specifically targeted at the condition as general supportive resuscitation does not provide definitive management.

    Diagnostic Process

    Diagnosis based upon presence of severe and life-threatening symptoms (fever, cardiovascular dysfunction, altered mentation) in a patient with biochemical evidence of hyperthyroidism.

    • Uncontrolled hyperthyroidism and thyroid storm exist on a continuum. Clinical judgement of severity required to make the thyroid storm diagnosis.

    Diagnostic decision tools:

    • Burch-wartofsky point scale
      • In patients with biochemical toxicosis, predicts likelihood of thyroid storm
      • Highly sensitive but poor specificity.
        • mildly uncontrolled hyperthyroid patient could screen positive in context of uncomplicated viral infection.

    Symptoms and signs

    • Patients tend to look very ill with prominent tremor, diaphoresis, mental status changes
      • Vitals: Tachycardia, hyperpyrexia
      • CVS: Sepsis mimic – fever + vasodilatory shock, CHF and associated symptoms, atrial fibrillation

    CNS: Confusion, agitation, anxiety, delirium, psychosis, stupor, coma

    • GI: Diarrhea, nausea, vomiting, abdominal pain, jaundice, hepatic failure
    • Other features of hyperthyroidism (diaphoresis, tremor, goiter, exophthalmos, lid lag)


    • High T4 + T3, with low TSH
      • Absolute values not typically more profound than standard untreated hyperthyroidism.
    • Evaluation of cause/precipitants + consequences
      • Glucose, electrolytes including Ca/Mg/Phos, LFTs, CBC, INR/PTT (to assess for DIC), CK (to assess for rhabdo), ECG
      • If infection suspected, blood cultures and infectious workup as indicated

    Recommended Treatment

    • Thionamide: Blocks new hormone synthesis; either of:
      • Methimazole 20mg po q4-6h
        • Preferred (less hepatotoxic), although does have risk of agranulocytosis
      • Propylthiouracil (PTU) 200-250mg po q4h
    • Iodine solution: Blocks the release of thyroid hormone
      • SSKI or Potassium Iodide and iodine (Lugol’s solution) one hour after first dose of thionamide (to prevent iodine usage as substate for thyroid hormone synthesis)
        • SSKI – 5 drops (50mg iodide/drop) po q6h
        • Lugol’s solution 10 drops (6.25mg iodide/iodine/drop) po q8h
      • Glucocorticoids: Reduces peripheral T4-to-T3 conversion, promotes vasomotor stability, possibly treats any associated adrenal insufficiency
        • Hydrocortisone 300mg IV loading dose, then 100mg IVq8h
      • Beta-Blocker: Carefully consider initiating a beta blocker to control the symptoms and signs
        • Propranolol 60-80mg po q4-6h or 0.5-1mg IV over 10 minutes followed by 1-2mg over 10 minutes q2-3h is preferred as it also blocks peripheral activation of T4 to T3
        • *beta-blocker may worsen cardiogenic or distributive shock*
          • Extreme caution is required, as beta blockers are contraindicated in patients with shock, or cardiogenic pulmonary edema
        • Bile acid sequestrants: May be of benefit in severe cases to decrease enterohepatic recycling of thyroid hormones
          • Cholestyramine 4g po q6h

    Presentation specific treatments:

    • Infection: reasonable to initiate empiric antibiotics in all febrile/hemodynamically unstable patients after blood cultures drawn before definitive diagnosis of thyroid storm made
    • Hyperthermia: initiate acetaminophen 650-1000mg q6h scheduled. Consider cooling blankets, if tolerated without shivering (aggressive overcooling can lead to vasoconstriction)
    • Agitation: can worsen hyperthermia or impeded ability to provide care. Consider olanzapine or midazolam PRN
    • Atrial fibrillation: General supportive measures such as volume repletion, vasoactive agents as required.
      • Aggressive rate control may precipitate cardiogenic shock in patients with compensatory tachycardia.
    • Find and treat precipitants

    Other treatment considerations:

    • Avoid NSAIDs and salicylates as they can increase levels of free T4 and T3.
    • Careful discontinuation from treatments can take place in ICU setting when defervescence and resolution of cardiovascular/CNS manifestations.

    Criteria For Hospital Admission

    Any patient with diagnosed thyroid storm should be admitted to an ICU, given life-threatening symptoms are necessary to make the diagnosis.

    Criteria For Transfer To Another Facility

    Patients with thyroid storm should be transferred to a facility with intensive care available. Transport should take place after initial treatments as described have been initiated.

    Quality Of Evidence?


    Evidence to support glucocorticoid use is low, based on expert recommendations.


    Related Information


    Related Information

    Reference List

    1. Thiessen, M. (2018). Thyroid and Adrenal Disorders in Rosen’s emergency medicine: Concepts and clinical practice (9th ed.). Philadelphia, PA: Elsevier/Saunders.

    2. Farkas, J. 2021. Thyroid Storm. Internet Book of Critical Care. Accessed from: http://emcrit.org/podcasts/thyroid-storm/

    3. Chiha M. et al Thyroid storm: an updated review. J Intensive Care Med. 2015 Mar;30(3):131-40.

    4. Ross,  D. 2022. UpToDate. UpToDate. Available from  https://www.uptodate.com/contents/thyroid-storm


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