Case Presentation: A 55-year-old female with alcohol use disorder and untreated hyperthyroidism was admitted to an outside hospital for abdominal pain, atrial fibrillation with heart rate in the 190’s, and hypotension requiring vasopressors and ICU care. Work up revealed low TSH (< 0.010 [range: 0.450 - 5.330]) and elevated free T4 (FT4) (4.74 [range: 0.60 - 1.60]) concerning for thyroid storm. She developed progressive organ dysfunction with transaminitis, acute kidney injury (AKI), and stress cardiomyopathy with ejection fraction of 20%. Methimazole and metoprolol tartrate were initiated; but, methimazole was discontinued after two days due to worsening transaminitis. On hospital day 3, she was transferred to our facility. On arrival, she was obtunded, ill-appearing, responsive only to noxious stimuli, with atrial fibrillation and rates in the 120’s, cool and dry distal extremities, hypothermia (96F), and a palpable, enlarged thyroid. Labs revealed lactic acidosis, transaminitis, AKI, low TSH (< 0.010) and elevated FT4 (3.71). She started on IV hydrocortisone, saturated solution of potassium iodine, and cholestyramine for thyroid storm, and a short course of epinephrine infusion for cardiogenic shock. Methimazole was held due to transaminitis. Given lack of improvement despite these interventions, the patient received plasmapheresis for rapid reduction of FT4. After two sessions of plasmapheresis FT4 decreased to 0.98 (from 3.71). Methimazole was reinitiated as transaminitis resolved, and propranolol was started for rate control for atrial fibrillation. Her FT4 further decreased to 0.53, and her mentation began to improve. She transferred out of the ICU and later underwent total thyroidectomy for definitive management. Post-operative PTH and calcium levels were normal. Ejection fraction improved to 38%. The patient was discharged on Levothyroxine and with plans for close follow-up with Endocrinology, Cardiology, and Surgery.
Discussion: Thyroid storm is typically managed with a beta blocker to manage increased adrenergic tone, a thionamide to block synthesis of new thyroid hormone, an iodinated solution to block the release of additional thyroid hormone, bile acid sequestrants to decrease enterohepatic recycling of thyroid hormone, and glucocorticoids to reduce the conversion of T4 to T3, promote vasomotor stability, and cover for relative adrenal insufficiency (2). This case highlights that plasmapheresis can also be pursued for treatment when traditional therapies are ineffective or contraindicated, such as in this case with worsening transaminitis on methimazole. Plasmapheresis is thought to work in thyroid storm by removing cytokines, antibodies, and thyroid hormones from circulation; however, the effects last for only about 24-48 hours (2). Therefore, plasmapheresis is typically used in emergent situations to stabilize patients for definitive treatment with thyroidectomy.
Conclusions: Thyroid storm is a rare, life-threatening illness requiring prompt diagnosis and treatment initiation in order to mitigate poor outcomes. In the USA, hyperthyroidism carries a prevalence of 1.3% with thyroid storm occurring in 0.22% of these patients. Overall mortality ranges from 8-30%. Thyrotoxicosis is typically managed medically; however, plasmapheresis can be considered for medically refractory cases (1). Plasmapheresis can quickly and efficiently decrease the total serum thyroid hormone concentration and can serve as a bridge to thyroidectomy in severe cases (2).
