EM resident. Colorado native, soon to be Husker transplant. Interested in Med Ed, wellness, and all things coffee
The Pre-brief
Although endocrine emergencies represent only a fraction of critical patients presenting to the ED and ICU, those with thyroid storm (TS) remain at high risk for significant comorbidity and mortality. Diagnosis of thyroid storm is made by evaluating for end-organ damage in the setting of thyrotoxicosis. Diagnostic criteria for TS has classically been based on the Burch-Wartofsky scoring system. Etiologies for thyroid storm vary; common precipitants include specific medications, autoimmune disease, surgery and illnesses. Treatment must follow a stepwise process in order to not exacerbate the patient’s current condition.
Evaluation:
- Consider this diagnosis in patients with fever or signs of increased sympathetic tone, such as those with new onset atrial fibrillation. As these are also signs of infection/sepsis, TS should be entertained in the differential diagnosis.
- It is important to note that when assessing patients using the Burch-Wartofsky criteria, only temperature and heart rate have true numerical cut-offs. Clinical features account for the remainder of the patient’s overall score.
- Thyrotoxicosis must be present, but thyroid lab values do not necessarily correlate with symptom severity.
- Common symptoms include:
- Neuro: thermoregulatory dysfunction, agitation, delirium, psychosis
- Cardiac: tachycardia, arrhythmia, CHF
- GI: abdominal pain, nausea, vomiting, liver dysfunction
Management:
Treatment of TS should be accomplished in a stepwise fashion:
- First, a beta-blocker (classically propranolol) to control symptoms from increased adrenergic tone.
- Next, a thionamide is administered to block de novo hormone synthesis, typically propylthiouracil (PTU), as it helps inhibit peripheral conversion of T4 to T3.
- Perhaps the most crucial step: iodine solution must be administered to block release of thyroid hormone. This must be given 1 HOUR AFTER the thionamide so as to not propagate further thyroid hormone synthesis. This floods the body with large quantities of iodine, temporarily inhibiting hormone release (known as the Wolff-Chaikoff effect).
- Steroids, such as hydrocortisone, are given to further reduce T4 to T3 conversion.
- Bile acid sequestrants (cholestyramine) may help decrease enterohepatic recycling of the thyroid hormone.
- As a last-ditch effort, plasmapheresis may be indicated. Surgical intervention may be required for those with Graves’ Disease if these patients are recalcitrant to medical management.
In addition to TS specific therapies, treatment of any predisposing illness (infection, MI) should be pursued.
Pro tip: Although fever can be treated with antipyretics, avoid salicylates as they can displace thyroxine from thyroid binding globulin, worsening thyrotoxicosis.
The Debrief
- TS is a rare, though life-threatening illness, and its etiology and triggers may be difficult to diagnose.
- Clinical manifestations of TS may present with a variety of signs and symptoms including hyperthermia, altered mental state, cardiac arrhythmia, hemodynamic instability and GI dysfunction.
- Prompt identification and initiation of treatment is necessary to avoid rapid decompensation and death.
- Treatment should consist of a beta-blocker, thionamide, iodine solution, steroids and bile acid sequestrants.
- If unsuccessful, plasmapheresis or surgery may be attempted.
References
- Akamizu T, Satoh T, Isozaki O, Suzuki A, Wakino S, Iburi T, Tsuboi K, Monden T, Kouki T, Otani H, Teramukai S, Uehara R, Nakamura Y, Nagai M, Mori M; Japan Thyroid Association. Diagnostic criteria, clinical features, and incidence of thyroid storm based on nationwide surveys. Thyroid. 2012 Jul;22(7):661-79. doi: 10.1089/thy.2011.0334. Epub 2012 Jun 12. Erratum in: Thyroid. 2012 Sep;22(9):979. PMID: 22690898; PMCID: PMC3387770.
- Bourcier S, Coutrot M, Kimmoun A, Sonneville R, de Montmollin E, Persichini R, Schnell D, Charpentier J, Aubron C, Morawiec E, Bigé N, Nseir S, Terzi N, Razazi K, Azoulay E, Ferré A, Tandjaoui-Lambiotte Y, Ellrodt O, Hraiech S, Delmas C, Barbier F, Lautrette A, Aissaoui N, Repessé X, Pichereau C, Zerbib Y, Lascarrou JB, Carreira S, Reuter D, Frérou A, Peigne V, Fillatre P, Megarbane B, Voiriot G, Combes A, Schmidt M. Thyroid Storm in the ICU: A Retrospective Multicenter Study. Crit Care Med. 2020 Jan;48(1):83-90. doi: 10.1097/CCM.0000000000004078. PMID: 31714398.
- Burch HB, Wartofsky L. Life-threatening thyrotoxicosis. Thyroid storm. Endocrinol Metab Clin North Am 1993; 22:263
- Chiha M, Samarasinghe S, Kabaker AS. Thyroid storm: an updated review. J Intensive Care Med. 2015 Mar;30(3):131-40. doi: 10.1177/0885066613498053. Epub 2013 Aug 5. PMID: 23920160.
