Thyroid Storm Research Articles

Exploring the role of plasmapheresis prior to thyroidectomy in managing thyrotoxicosis: a comprehensive scoping review.

A thyroid storm is the most extreme and life-threatening presentation of thyrotoxicosis. Thyroidectomy can be used for definitive treatment. It should be performed after euthyroidism is accomplished. The use of therapeutic plasma exchange (TPE) is a last resort option in cases where standard pharmacological therapy proves to be ineffective. Due to its rare prevalence, there are limited data evaluating the usefulness and efficacy of TPE as a bridging therapy to thyroidectomy. The absence of relevant literature prompted us to conduct a scoping review. The following bibliographic databases were searched for articles dated 30 November 2023: Medline, EMBASE, Web of Science and Google Scholar. The search identified 1047 records, of which 42 articles were accepted with a total of 234 patients. The dominant indications for TPE were side effects due to conventional treatment. The mean fT4 level decreased 51.9% of baseline after TPE, while the mean fT3 level decreased 66.6% of baseline. The main side effects observed with FFP were allergic reactions, while the use of an albumin solution was associated with perioperative bleeding. Based on the limited data available in the literature, we recognize plasmapheresis as an effective treatment option for reducing thyroid hormone levels prior to thyroidectomy in patients with thyrotoxicosis. Available data suggest that it might be reasonable to limit the number of sessions in favor of an earlier surgical intervention. To reduce the risk of bleeding, FFP may be a better option as a replacement fluid, especially in the session prior to thyroidectomy.

8091 Clinical Features Associated with ICU Admission and Mortality in Thyroid Storm and Impending Thyroid Storm

Abstract Disclosure: E.D. Zhang: None. I. Hussain: None. Introduction: Thyroid storm is a rare, life-threatening manifestation of thyrotoxicosis characterized by a clinical syndrome of acute multi-organ failure, which can result in significant morbidity and mortality. Impending thyroid storm is a stage of thyrotoxicosis that may progress to thyroid storm if untreated. The aim of this study was to evaluate the demographics and outcomes of patients with thyroid storm at our institution and determine the clinical features associated with severe complications and mortality. We also evaluated the differences in clinical features and outcomes in patients diagnosed with impending thyroid storm versus thyroid storm. Methods: This was a retrospective single-center cohort study evaluating patients aged 18 years or older who were clinically diagnosed with thyroid storm or impending storm at two affiliated tertiary academic centers from 2008-2021. A search of the electronic medical record system using ICD-10 codes for thyroid storm identified patient charts which were reviewed for eligibility. Results: This study included 121 admissions, with 75 (62.0%) patients with thyroid storm and 46 (38.0%) patients with impending thyroid storm. Our study cohort was notably more racially and ethnically diverse than prior U.S. studies with 5.0% non-Hispanic White, 52.9% Black, 33.9% Hispanic, and 8.3% Asian patients. The mortality rate was 4.7%, with all patient deaths occurring in the thyroid storm group. Multivariable logistic regression analysis showed atrial fibrillation (OR 4.09, 95% CI 1.21, 13.85, p=0.02) and acute respiratory failure (OR 22.18, 95% CI 2.29, 215.19, p=0.008) to be significantly associated with a composite outcome of intensive care unit (ICU) admission or death. Comparison of impending storm and thyroid storm groups showed fever (p=0.02), acute respiratory failure (p=0.03), and ICU admission (p=0.02) to be significantly different between groups. Conclusions: This study describes the largest published single-center cohort of patients treated for thyroid storm in the United States. Furthermore, our study contributes importantly to the data for racial/ethnic minorities who are under-represented in prior studies. The mortality rate in this study is lower than most recent studies. The presence of atrial fibrillation and acute respiratory failure were noted to be significantly associated with a composite outcome of ICU admission or death, and the five fatal cases had high rates of cardiac arrest and shock. These findings suggest that complications involving cardiopulmonary compromise are clinically important in predicting severe disease and poor outcomes. Acute respiratory failure was also noted to be significantly different between impending storm and thyroid storm groups indicating that while not currently included in existing diagnostic systems, it is an important complication of thyroid storm that may have prognostic value. Presentation: 6/2/2024

5114 Establishment of Thyroid Storm Mouse Model and Therapeutic Effects of Ghrelin

Abstract Disclosure: C. Kurimoto: None. Y. Furukawa: None. T. Akamizu: None. A. Doi: None. K. Takeshima: None. S. Morita: None. H. Iwakura: None. H. Ariyasu: None. H. Furuta: None. M. Nishi: None. T. Matsuoka: None. Context: Thyroid storm (TS), a life-threatening condition that can damage multiple organs, is caused by a combination of thyrotoxicosis and severe physical stresses. Infection is the most common triggering factor. Hypercytokinemia is a suggested background, but the pathological condition is unclear and there are no appropriate animal models. Further, TS has limited therapeutic options. Objectives: We aimed to confirm the hypercytokinemia in patients with TS, establish a TS model mouse by triiodothyronine and lipopolysaccharide administration, and explore the therapeutic effects of ghrelin on TS. Methods: We evaluated serum IL-6 levels as a representative marker of hypercytokinemia in patients with TS. As a TS model, C57BL/6 mice were titrated with triiodothyronine and lipopolysaccharide to develop a lethal model with approximately 30% survival at 24 hours. We assessed the survival ratio, mouse sepsis scores and blood biomarkers (IL-6, metanephrine, alanine aminotransferase) and evaluated the effects of ghrelin on these parameters. Results: Serum IL-6 was increased in patients with TS compared with those with Graves' disease without TS (55.7 ± 69.0 vs. 3.13 ± 1.41 pg/mL, P < .05, n=4 each). Next, we titrated the doses of T3 and LPS, aiming to achieve a survival rate of approximately 30% at 24 hours after administration. Two out of five mice in the T3 3.0 mg/kg group died, while none of the eight mice in the T3 1.0 mg/kg group died. Therefore, we determined that the appropriate T3 dose for the TS mouse model is 1.0 mg/kg, which is not lethal when administered alone. In the T3 1.0 mg/kg group (n=8), serum FT3 levels were approximately three times higher (15.3 ± 4.5 vs. 4.5 ± 0.7pg/ml) than those in the control group (n=8). Next, different doses of LPS was added to the T3 group. Survival at 24 hours post-dose was 60% in the T3 + LPS 0.2 mg/kg group (n=5) and 33% in the T3 + LPS 0.5 mg/kg group (n=5), while survival was 100% in the LPS 0.5 mg/kg alone group (n=5),. Based on these findings, the dosage for the murine TS model was determined to be “triiodothyronine 1.0 mg/kg and lipopolysaccharide 0.5 mg/kg”. This TS model group had increased mouse sepsis score, serum IL-6, metanephrine and alanine aminotransferase. In this model, the ghrelin at 300 µg/kg improved the survival rate to 66.7% (P < .01, vs. 0% [saline-treated group]) as well as the mouse sepsis score, and it decreased the serum IL-6 and metanephrine. Conclusion: We confirmed the hypercytokinemia in patients with TS. Next, we established a lethal model simulating TS by inducing “thyrotoxicosis” by exogenous administration of thyroid hormones, and by inducing “sepsis” by intraperitoneal administration of LPS. The model mice exhibited similar pathophysiological status to human TS associated with induction of serum IL-6 and other biomarkers, which were improved by ghrelin. Presentation: 6/1/2024

8630 Cardiorespiratory Failure in Thyroid Storm After C-section in a Patient with Untreated Hyperthyroidism

Abstract Disclosure: I.C. Arroyo: None. M. Ramirez: None. M. Alvarado: None. L.R. Sepulveda-Garcia: None. L. El Musa Penna: None. W. Medina-Torres: None. Z. Maisonet -Feliciano: None. J. Segarra-Villafane: None. Unrecognized hyperthyroidism during pregnancy increases the risk of maternal and fetal complications, including miscarriage, pre-eclampsia, maternal congestive heart failure, and intrauterine growth restriction (IUGR). Thyroid storm is a rare but life-threatening complication that can occur as well. Furthermore, it can present with cardiopulmonary failure which increases risk of death. Recognizing it early and providing intensive and ongoing therapy is imperative for a positive outcome.We report a case of a 29-year-old female G4P2A0 with triplet pregnancy who developed thyroid storm after an emergency C-section at 27 weeks of gestation due to sinus tachycardia and IUGR in one of the fetuses.Past medical history was remarkable for hyperthyroidism diagnosed on first pregnancy that did not require treatment.Upon questioning, she referred unintentional weight loss, palpitations, tremors, and heat intolerance in the past months.Physical examination showed sinus tachycardia, fine hand tremors, non-tender goiter, and thin/brittle hair.One day after C-section thyroid function tests (TFT) were remarkable for suppressed TSH <0.008uIU/mL, FT4 at 4.30 (0.89-1.76ng/dL) and positive thyroid stimulating antibodies. Burch-Warsofsky Point Scale (BWPS) for Thyrotoxicosis of 20 points didn’t indicate current or impending thyroid storm. Methimazole and propranolol were started. Two days after C- section patient developed worsening FT4 at 5.63ng/dl, worsening sinus tachycardia, increased temperature and respiratory failure requiring mechanical intubation. 2 D echocardiogram showed right ventricular overload with pulmonary hypertension, while CT angiogram of thorax suggested thyrotoxic cardiomyopathy. BWPS was now at 45 points compatible with thyroid storm (positive criteria for temperature of 38.4, heart rate of 117 bmp and heart failure). At this time methimazole was switched to propylthiouracil (PTU), propranolol was adjusted, and hydrocortisone, in addition to cholestyramine, were started. After these changes in therapy, TFTs improved markedly and a stable clinical state was achieved, with successful extubation.Untreated hyperthyroidism during pregnancy and post-partum period poses significant risks, including thyroid storm. Our patient had a C-section with worsening TFTs despite methimazole therapy, developing thyroid storm with cardiopulmonary failure. Cardiopulmonary failure is a rare, but deadly presentation of thyroid storm. In this case C-section was identified as a stressor for thyroid storm and cardiorespiratory failure as a complication. Prompt recognition and aggressive treatment of this potentially lethal condition is warranted to improve survival in thyrotoxic cardiomyopathy. Presentation: 6/1/2024

9396 Deciphering The Enigma: A Case Report On New-onset Graves Disease Presenting As Thyroid Storm In The First Trimester Of Pregnancy, Managed In The Intensive Care Setting

Abstract Disclosure: M. Zeb: None. S.W. Salari: None. A. Tiwari: None. A. Vadher: None. A. Dabaja: None. S. Kambhatla: None. Graves' disease, an autoimmune disorder characterized by hyperthyroidism, presents unique challenges when manifesting as thyroid storm during pregnancy. We report a case of a 27-year-old African American woman at 9 weeks gestation who presented with palpitations, agitation, and fever. On examination, she exhibited fever, tachycardia, tremors in hands, and mild bilateral exophthalmos. Thyroid function tests revealed markedly elevated free thyroxine and suppressed thyroid-stimulating hormone levels. Thyroid ultrasound confirmed diffuse thyroid enlargement with increased vascularity, consistent with Graves' disease. Pelvic ultrasound estimated the gestational age at 9 weeks and 2 days, with a serum β-hCG level of 135,037 mIU/mL. An electrocardiogram revealed sinus tachycardia, and a complete metabolic panel indicated mild hypokalemia. The Thyroid Stimulation Immunoglobulin (TSI) and Thyrotropin receptor antibodies were tested positive. The Burch-Warsofsky point score of 45, supported the diagnosis of thyroid storm. The patient received intensive care treatment including intravenous fluids, hydrocortisone, beta-blockers, Lugol’s iodine, propylthiouracil, and potassium replacement. Following treatment, thyroid function stabilized within 48 hours, and her hyperthyroid symptoms resolved. The patient was discharged on oral labetalol and propylthiouracil. Thyroid storm, characterized by severe manifestations of hyperthyroidism, is a rare but potentially life-threatening condition, especially during pregnancy. Prompt recognition and intervention are crucial due to associated maternal and fetal morbidity and mortality. A multidisciplinary approach, involving endocrinology, obstetrics, and critical care, is essential to optimize outcomes. The unique physiologic changes of pregnancy, such as increased thyroid hormone production and altered thyroid hormone-binding globulin levels, can complicate the diagnosis and management of hyperthyroidism. Our case underscores the importance of vigilance for thyroid dysfunction in pregnant women, even in the absence of prior thyroid disease. Additionally, the potential impact of hyperthyroidism and thyroid storm on pregnancy outcomes highlights the need for early recognition and intervention. Long-term management of Graves' disease during pregnancy may also require adjustment of antithyroid medication dosage and monitoring of thyroid function to maintain euthyroidism while minimizing fetal exposure to medication. Further research is warranted to refine diagnostic criteria, treatment protocols, and long-term management strategies for thyroid storm in pregnancy. Increased awareness among healthcare providers about the risks and management strategies for this rare but serious complication is also necessary. Presentation: 6/3/2024

6973 Prospective Multicenter Registry-Based Study on Thyroid Storm: The 2016 Guidelines for the Management from the Japan Thyroid Association and Japan Endocrine Society Are Useful

Abstract Disclosure: Y. Furukawa: None. K. Tanaka: None. O. Isozaki: None. A. Suzuki: None. T. Iburi: None. K. Tsuboi: None. M. Iguchi: None. N. Kanamoto: None. K. Minamitani: None. S. Wakino: None. T. Satoh: None. S. Teramukai: None. E. Kimura: None. Y. Miyake: None. T. Akamizu: None. Context: The mortality rate in thyroid storm (TS) has been reported to be higher than 10%. Even when patients survive, some have irreversible damages. In order to improve the prognosis of patients with TS, appropriate management as well as prompt and accurate diagnosis are needed. We created the diagnostic criteria in 2012 and established guidelines for the management of TS in 2016. Objective: We aimed to evaluate the effectiveness of the 2016 guidelines for the management of TS proposed by the Japan Thyroid Association and Japan Endocrine Society. Design: Prospective registry-based study through a secure web platform. Setting: Prospective multicenter registry. Patients and Measurements: Patients with new-onset TS were registered in the Research Electronic Data Capture (REDCap) from May 1, 2018 to April 30, 2022, over four years. On day 30 after admission, clinical information and prognosis of each patient were added to the platform. On day 180, the prognosis was described. The questionnaire consisted of 176 items totally. Results: This study included 110 patients with TS (93 definite and 17 suspected). The median of Acute Physiology and Chronic Health Evaluation (APACHE) II score was 13, higher than the score in the previous nationwide survey, 10 (p=0.001). Nonetheless, the mortality rate at day 30 was 5.5%, approximately half compared with 10.7% in the previous nationwide survey (p=0.13). Lower BMI, lower left ventricular ejection fraction (LVEF) and shock were positively associated with poor prognosis at day 30. The lack of fever ≥ 38°C was surprisingly associated to the outcome. Approximately 80% of doctors followed the guidelines. The mortality rate in patients with an APACHE II score ≥ 12 for whom the guidelines were not followed was significantly higher than the rate in patients for whom the guidelines were followed (50% vs. 4.7%) (p=0.01). Conclusions: Prognosis seemed better than in the previous nationwide survey, even though disease severity was higher. The mortality rate was lower when the guidelines were followed. Thus, the guidelines are useful for managing TS. Presentation: 6/2/2024

5128 Role of Plasmapharesis- A Tale of Two Thyroid Storms

Abstract Disclosure: Z. Zhang: None. S. Joseph: None. A.M. Kodali: None. D. Eagerton: None. Background: Thyroid storm is an acute life threatening endocrinological emergency. The standard treatment for a thyroid storm is antithyroid medication, iodine, beta blockers and corticosteroids. However, when patients are refractory to standard treatment, plasmapheresis may be an effective and safe intervention. Case 1: A 49-year-old male with typical symptoms of hyperthyroidism, presented with a Ventricular tachycardia arrest. After the return of spontaneous circulation, he was febrile, and developed new onset atrial fibrillation (AF) and Amiodarone drip was started. Physical exam showed a thin gentleman with an enlarged thyroid. ECHO showed LVEF 50% with moderate to severe dilatation of left atrium and mild mitral and tricuspid valve regurgitation. CT abdomen/pelvis and CTA chest did not show any pathology. Labs showed TSH of 0.02 (reference range: 0.465-4.68); Free T 4 >6.99 (reference range: 0.78- 2.19). He was started on Propylthiouracil (PTU), Hydrocortisone, Potassium Iodide, and Cholestyramine. His blood pressure was too low to tolerate a beta blocker. He developed increased liver enzymes thought to be due to shocked liver. PTU was switched to Methimazole due to less risk of hepatotoxicity. A Thyroid Stimulating immunoglobulin was 13.40 (reference range 0.00-0.55), confirming Graves’ disease. He developed multiorgan failure and plasmapheresis was initiated. His Free T4 level prior to his first apheresis was still >6.99 but improved to 6.20 after two days. After the second session, free T4 level drastically improved to 2.65. He sustained a level of 2.09 until his hospital discharge. Case 2: A 59-year-old male with untreated hyperthyroidism and AF, who presented with shortness of breath. He was tachycardic, febrile and developed AF with rapid ventricular response. A TSH and free T4 level showed <0.02 (reference range: 0.465-4.68); and >6.99 (reference range: 0.78- 2.19), respectively. Physical exam shows a cachectic man with an enlarged thyroid. ECHO showed reduced ejection fraction of 35% with biventricular failure. He was initially started on PTU, Potassium Iodide, hydrocortisone and esmolol drip and eventually Cholestyramine. Patient developed multisystem organ failure and PTU was switched to methimazole due to continued deterioration of his liver enzymes. Plasmapheresis started with a total of 3 sessions. His free T4 improved from 4.32 to 3.59 by the second session. Round three was performed when his Free T4 increased back to 4.56. Unfortunately, he had a sudden decline in mentation and CT head showed an acute/subacute left anterior parietal stroke and after family discussion, was palliatively extubated and expired. Discussion: This case series shows two cases of thyroid storm treated with plasmapheresis and had two stark contrasts. Further studies should be done to elucidate the usefulness of plasmapheresis for thyroid storm when refractory to standard of treatment. Presentation: 6/2/2024

8113 Thyroid Storm in a Patient with Thyroid Nodule on Anticoagulation

Abstract Disclosure: R. Kulkarni: None. S.S. Krishnasamy: None. N. Mon: None. R. Downs: None. Background: There are very few case reports related to hyperthyroidism due to anticoagulation use. We describe a case, of a less common cause of hyperthyroidism due to hemorrhagic thyroiditis in a patient on anticoagulation and history of metastatic colon cancer. Clinical case: A 67-year-old white male with PMH significant for colon cancer with liver metastasis s/p exploratory laparotomy with sigmoid colectomy, end-colostomy with Hartman's pouch creation, pre-diabetes, recent left IJ & axillary vein thrombus on Eliquis, and thyroid nodule; presented with complaints of shortness of breath, difficulty swallowing and dizziness. Other symptoms included weight loss, complaints of heart racing and generalized body aches. The patient had a recent admission for similar complaints and was newly diagnosed with left IJ/axillary vein thrombus and expanding hemorrhagic thyroid nodule on imaging. He was discharged on anticoagulation for the DVT with 2 week follow up for elective thyroidectomy for goiter. The patient was admitted to the ICU for worsened respiratory status needing ventilatory support and pressor support. Physical findings on admission included jaundice, sinus tachycardia, lethargy with agitation. Initial labs showed TSH 0.02 uIU/mL, FT4 4.85 ng/dL and FT3 6.8 pg/mL, LFTs >500 U/L. Burch-Wartofsky Point Scale score was >60 suggestive of thyroid storm. Imaging with PET CT was concerning for thyroid enlargement with multiple nodules with increased uptake. Thyroid US was consistent with heterogenous gland with hemorrhagic nodules. Based on clinical history, physical findings, diagnostic labs, and imaging the patient was diagnosed with severe hyperthyroidism with thyroid storm secondary to hemorrhagic thyroid nodules in the setting of anticoagulation. The patient underwent thyroid artery angiogram with particle embolization of left inferior and right superior thyroid arteries. Endocrinology started the patient on methylprednisolone, cholestyramine and propranolol. Thionamide was held since the patient had abnormal liver function tests in the setting of shock liver. The patient’s thyroid function slowly improved on current regimen to TSH 0.05 uIU/mL, FT4 1.7 ng/Dl and FT3 4.1 pg/mL on day 3. At the family interdisciplinary meeting, due to guarded prognosis, family opted for comfort care, and the patient finally succumbed to multiple co-morbidities. Conclusion: The case presented discusses diagnosis and management of less common causes of hyperthyroidism and management of thyroid storm in liver dysfunction. The patient would have needed a thyroid biopsy at a later date to rule out colonic metastasis as a cause of hemorrhage if he had survived the thyroid storm and comorbid illnesses. Presentation: 6/3/2024

9398 Early Identification of Impending Thyroid Storm Leading to Improved Thyrotoxic Induce Cardiomyopathy

Abstract Disclosure: D.H. Sacoto: None. D. Patel: None. A. De Rosairo: None. K. Madani: None. B. Singh: None. A. Bonilla Campos: None. R. Belokovskaya: None. F. Alberto A.: None. Introduction: Heart failure can be the leading presentation in 6% of thyroid storm cases and is the leading cause of death, particularly in elderly patients. However, its importance lies in symptom control and heart function reversibility once the euthyroid state is achieved. We present a caseof thyroid storm-induced atrial fibrillation (Afib) leading to severe systolic dysfunction. Case: A 61-year-old female with a history of Graves’ disease (GD) presented to the ED with two months of palpitations and one week of shortness of breath. There were bibasilar lung crackles, irregular heart rhythm, pedal edema, and thyromegaly at the examination. EKG was consistent with Afib with rapid ventricular response (123-135 beats per minute); She was tachypneic (respiratory rate: 40 per minute) and hypoxemic (87% O2 saturation), which required bilevel positive airway pressure. Otherwise, hemodynamically stable (BP: 127/106 mmHg). Laboratories showed negative troponin T (<0.010 ng/mL, n <0.01 ng/mL). However, elevation of Pro-B-type natriuretic peptide (6000 pg/mL, n <125 pg/mL), an x-ray displaying bibasilar pleural effusions and an echocardiogram demonstrating a severely reduced ejection fraction (EF) (21%, n 50-70%), myocardial perfusion scan was normal. Thyroid evaluation showed a suppressed TSH (<0.01 uIU/mL, n 0.27-4.20 uIU/mL) with elevated free T4 (5.8 ng/dL, n 0.9-1.8 ng/dL), free T3 (202 ng/dL, n 2.0-4.4 ng/dL), and TSI (8.25 IU/L, n 0-0.55 IU/L). A thyroid ultrasound revealed increased vascular flow on the left thyroid lobe. A Burh-Schakowsky score of 45 points was consistent with impending thyroid storm. She was started on methimazole, cholestyramine, and propranolol. Three months follow-up, she was asymptomatic, TSH normalized (4.12 uIU/mL), and mild improvement of cardiac EF 25%. Discussion: A thyroid storm in the setting of GD often presents after precipitating factors such as surgery, infection, or, as in our case, anti-thyroid medication non-compliance. Increased thyroid hormone levels upregulate cardiac β receptors, enhancing sensitivity to sympathetic innervation. These can shorten the refractory period of cardiomyocytes, leading to tachyarrhythmias, with Afib occurring in 20% of patients. Chronic tachycardia finally impairs left ventricle function, with heart failure as an outcome. A high index of suspicion and the ability of early diagnosis of impending thyroid storm is critical since the first laboratory confirmation is often delayed, and second, either anti-thyroid medication, radioactive iodine ablation or thyroidectomy, in addition to non-selective beta-blockers, can reverse cardiac dysfunction and lead to clinical improvement as early as 12 -Twenty-four hours of medical treatment. In our case, the early diagnosis and treatment of thyroid storm, in addition to the rate control prevented a deadly outcome and contributed to the improvement of heart failure. Presentation: 6/1/2024

8232 Therapeutic Plasma Exchange as a Bridge to Total Thyroidectomy in a Patient with Refractory Thyroid Storm

Abstract Disclosure: A. Sridhar: None. T. Chaudhary: None. S. Patil: None. A. Prabha Kumar: None. K. Djekidel: None. B.C. Jameson: None. Background: Thyroid storm is a rare life-threatening complication of hyperthyroidism with a mortality rate of 10-30%. Therapeutic plasma exchange (TPE) could be a bridge to definitive total thyroidectomy in patients with refractory disease who fail conventional therapy. Clinical case: Patient is a 31-year-old male with a past medical history of untreated hypertension, anxiety, alcohol use, substance abuse and a family history of Graves’ disease. He presented with complaints of breathing difficulty, back and shoulder pain for the past 1 day. In the ED he was found to be in respiratory distress with a rate of 40/min. He was started on a non-rebreather mask and was eventually intubated due to worsening distress. He was tachycardic with a heart rate of 130/min and had elevated blood pressure at 170/105 mm Hg. Physical examination was significant for diaphoresis, accessory respiratory muscle use, and diffuse swelling on the front of the neck. His blood work was significant for hemoglobin 11.1g/dL, TSH <0.01 uIU/mL, FT3 >32.6 pg/ml, FT4>7.8 ng/dL and urine drug screen was negative. Chest X-ray showed mild perihilar vascular congestion due to pulmonary edema. CT neck showed nonspecific diffuse enlargement of the thyroid gland without dominant thyroid nodule. The patient was admitted to the ICU for management of thyroid storm likely from Graves’ disease. Burch-Wartofsky Point Scale score on admission was 60. Endocrinology was consulted and the patient was started on IV hydrocortisone 100 mg and IV Methimazole 20 mg every 8 hours, propranolol 60 mg every 6 hours, and iodine drops 300 mg every 6 hours after the first dose of methimazole. Since repeat FT4 after 48 hours showed no improvement, he was switched to Propylthiouracil (PTU) with a loading dose of 500mg every 4 hours for 2 doses followed by 250 mg every 6 hours and cholestyramine 4 g orally 4 times daily to reduce enterohepatic circulation of thyroid hormone. After 3 days of PTU, the patient’s FT3 was improving but FT4 continued to be elevated. ENT was consulted for total thyroidectomy, but the patient required preparation to improve FT4 levels prior to surgery. He was transferred to a tertiary care center on Day 6 of admission to undergo TPE. After 3 sessions of TPE serum FT3 and FT4 decreased, patient’s mentation improved, and he was extubated on Day 10 of admission. He received a total of 5 sessions of TPE and underwent total thyroidectomy on Day 15 of admission without complications. Postoperatively he was started on oral Levothyroxine 125 mcg once daily and calcitriol 0.25 mcg twice daily. Patient continues to follow up with Endocrinology clinic for thyroid function monitoring and medication adjustment. Conclusion: Given the high mortality rate associated with thyroid storm, early recognition of refractory disease is imperative. Bridging with TPE while awaiting total thyroidectomy improved clinical outcomes in our patient and should be considered in such cases. Presentation: 6/3/2024

6423 The Storm in a Healthy 26-year-old Hispanic Female

Abstract Disclosure: P.M. Reyes-Torres: None. M. Hernandez-Hernandez: None. Uncontrolled hyperthyroidism can cause thyrotoxicosis and lead to end-organ dysfunction known as thyroid storm. The incidence is .20 and .76 per 100,000 persons per year, with an incidence of 4.8–5.6 per 100,000 hospitalized patients. Of those hospitalized with thyrotoxicosis in the U.S., thyroid storm is diagnosed in 16%. Most commonly affects females, middle-aged patients, and Caucasians. Can be precipitated by acute illnesses, surgery, or non-compliance with medications. Symptoms are characterized by fever, cardiac and gastrointestinal dysfunction, and altered mentation along with impaired thyroid function tests.A 26-year-old Hispanic female presented to our ER complaining of palpitations, general malaise, dysphagia, and fevers after attending a social event 3 days before. Physical examination revealed a fever of 101F, restless patient with pressured speech, and diffusely enlarged non-tender thyroid without discrete nodules. Labs were remarkable for WBC: 12 000, urinalysis, b-HCG, and CXR were all negative. Burch-Wartofsky Point Scale: 55 and biochemical tests (TSH: 0.005 ml/UL, free T4 >5 ng/dL, Total T3: 8.5 ng/mL, Total T4: 28.87 uG/DL, Thyroglobulin 34.81 ng/mL) for which diagnosis of thyroid storm was made. She was transferred to the ICU and treatment was initiated with fluids, Propranolol 60 mg PO q4hrs, PTU 250 mg PO q4hrs, and Hydrocortisone 300 mg IV as loading dose then 100mg IV q8hrs. TSI and TRAb were ordered. Thyroid US remarkable for bulky thyroid gland with heterogeneous, increased vascularity, no obvious cystic/solid lesions seen. Repeated tests showed a decreasing trend of free T4: 4.71 ng/dL and Total T3: 2.42ng/dL for which PTU was discontinued and Methimazole 15 mg PO BID was started. Five days after treatment started, the patient continued symptom-free and was discharged with Propranolol 60 mg PO q6hrs and Methimazole 15 mg PO BID. TSI and TRAb samples were obtained but results were pending before discharge. Follow-up was scheduled in 2 weeks with routine labs but the patient was lost to follow-up.This case highlights the importance of early recognition and treatment of thyroid storm in Hispanics, undiagnosed patients given the presenting nonspecific, life-threatening symptoms. We conclude that our patient's cause of thyrotoxicosis was an undiagnosed case of Graves Disease and the storm was most likely triggered by an upper viral respiratory tract infection. This case could potentially help physicians identify hyperthyroidism in an earlier phase, reducing incidence, mortality, and hospitalizations of thyroid storm since a variety of mimics make the diagnosis challenging. Furthermore, we could contribute to updated statistical knowledge regarding the risk of patients with thyrotoxicosis developing thyroid storm which despite advancements in technology, are currently lacking. Presentation: 6/1/2024

8238 Thyroidectomy for Thyroid Storm Complicated by Drug-Induced Hepatotoxicity and Thyrotoxic Cardiopulmonary Disease

Abstract Disclosure: T.A. John: None. A.C. Suarez: None. J. Genkil: None. S. Patil: None. C. Anastasopoulou: None. Case Presentation: A 59-year-old female with hypertension and type 2 diabetes presented with palpitations, and several months of hyperthyroid symptoms, lower extremity swelling, and dyspnea on exertion. On presentation, patient was diaphoretic, tachycardic, volume overloaded and had symmetric swelling of the thyroid gland. Lab results revealed FT4 3.28 ng/dL, total T3 384.59 ng/dL, TSH < 0.01 µIU/mland elevated TSI. Electrocardiogram showed sinus tachycardia. Chest radiography showed pulmonary edema. Echocardiography showed a reduced ejection fraction of 35%, dilation of right ventricle, severe mitral and tricuspid regurgitation, and severely elevated pulmonary artery systolic pressure (55-60 mm Hg). Thyroid ultrasound revealed enlarged, heterogeneous thyroid gland with normal vascularity. The diagnosis of thyroid storm due to Graves' disease was made with a score of 50 on the Burch-Wartofsky Point Scale. Patient was started on propylthiouracil (PTU), metoprolol tartrate and furosemide. Corticosteroid therapy was not utilized due to the risk of worsening heart failure from sodium retention. After two days of PTU, patient developed drug induced liver injury (DILI). Patient was then transitioned to methimazole which was also discontinued thereafter due to progression of DILI. She was started on potassium iodide to suppress thyroid hormone production, and N-Acetyl cysteine (NAC) for DILI. Due to persistent thyrotoxicosis, the patient underwent a total thyroidectomy on hospital day 13 and was started on levothyroxine for post-surgical hypothyroidism. Liver function returned to normal on day 16. A surveillance echocardiogram obtained 3 months later showed recovered biventricular function (ejection fraction 55-60%), mild mitral and tricuspid regurgitation and normal pulmonary pressures. Educational value: Thyroid storm is an uncommon, life-threatening emergency. Thioamides remain the cornerstone of treatment, but rarely, they can result in adverse events such as hepatotoxicity. When thioamides are contraindicated, other agents (e.g., iodine, lithium, potassium perchlorate, cholestyramine, glucocorticoids) can be utilized; however, refractory cases might require total thyroidectomy as definitive treatments. Our patient had marked recovery of cardiac function and resolution of pulmonary hypertension and DILI after timely surgical intervention. Multidisciplinary care is pivotal for the successful management of thyroid storm. Presentation: 6/3/2024

7046 Thyroid Storm After Thyroidectomy Without Underlying Hyperthyroidism

Abstract Disclosure: A.J. White-Cotsmire: None. B. Kodali: None. C. McHenry: None. M. Rahhal: None. Background: Thyroid storm is a feared complication of total thyroidectomy; however, this is a rare phenomenon seen primarily in patients with undiagnosed or poorly controlled thyrotoxicosis from Graves’ disease. Preoperative treatment of patients with hyperthyroidism with beta-adrenergic blockers and anti-thyroid medication to ensure that patients are euthyroid prior to thyroidectomy have largely eliminated this risk of thyroid storm. (1) We report a case of thyroid storm caused by release of preformed thyroid hormone, following extensive manipulation and resection of a large retrosternal nontoxic multinodular goiter. To our knowledge, this has not yet been previously described. Clinical Case: A 57yo female underwent a total thyroidectomy with resection of a large benign multinodular goiter with retrosternal extension, which was causing compressive symptoms. She had a nodular goiter for 7 years that was increasing in size. Fine needle aspiration 2 years prior to surgery demonstrated colloid and adenomatoid nodules with Hurthle cell changes. She had no history of hypo- or hyperthyroidism. TSH prior to surgery was 0.576µIU/ml (normal = 0.450-5.330µIU/ml). Extensive manipulation was required to deliver the goiter from beneath the manubrium. Pathology from her thyroid revealed a multinodular goiter without evidence of malignancy. Post-operative course was uncomplicated, and after an overnight stay, the patient was discharged home with 150mcg (1.5mcg/kg) levothyroxine daily. She presented to the emergency department 4 days later and was admitted to the intensive care unit with diffuse abdominal pain, nausea, vomiting, and myalgias, and she was diagnosed with atrial fibrillation with rapid ventricular response. TSH on admission was 0.020 µIU/ml, thyroglobulin levels were >2,250.0ng/mL (n=0.8 – 48.0 ng/mL), thyroglobulin antibodies were negative. Her levothyroxine was stopped, her heart rate was controlled with metoprolol, and she was started on oral anticoagulation with rivaroxaban. She was discharged after a 7-day hospital stay. At 3 weeks follow-up her TSH was 35.67µIU/ml and her thyroglobulin levels were 23.9ng/mL. Her symptoms had resolved, and levothyroxine was resumed at a lower dose of 137mcg daily. Six weeks later her TSH level was 7.785µIU/ml, and her thyroglobulin was 1.8ng/mL. Conclusion: To our knowledge, this is the first case of thyroid storm reported following thyroidectomy in a patient with nontoxic multinodular goiter in a clinically and biochemically euthyroid patient. Massive increase in thyroglobulin postoperatively and rapid resolution of symptoms suggest that the release of preformed thyroid hormone related to vigorous thyroid manipulation was likely the cause. Reference: (1) Christou N, Mathonnet M. Complications after total thyroidectomy. Journal of Visceral Surgery. 2013;150(4):249-256. doi:10.1016/j.jviscsurg.2013.04.003 Presentation: 6/1/2024

5125 Severe Gestational Thyrotoxicosis Leading to Unwarranted Treatment

Abstract Disclosure: C. Bell: None. L.A. Barbour: None. Introduction: Gestational transient thyrotoxicosis (GTT) is the most common cause of thyrotoxicosis in pregnancy yet is often confused with Graves’. Although usually mild, we present a severe case leading to the unsupported use of anti-thyroid drugs (ATDs), which could have resulted in fetal hypothyroidism if continued. Case: A 30-year-old female G1P0 at 10 wks with a single gestation presented with 4 wks of vomiting, palpitations, and weight loss. She had no history of thyroid disease. She was diaphoretic and ill-appearing and had a non-tender, smooth normal-sized thyroid, a stare without exophthalmos, and a fine tremor. TSH was < 0.01, FT4 5.57 ng/dL (0.89-1.76), and TT3 201 ng/dL (60-181). TPO Ab 51 (< 60). TRAb, TSI Ab, and TgAb were negative. β-hCG level was 334,106 mIU/mL. She was diagnosed with GTT and briefly hospitalized for dehydration but was re-hospitalized 2 wks later with worsening symptoms and 25 lb weight loss. Unexpectedly, her FT4 and TT3 rose to 6.24 ng/dL and 339, respectively. A thyroid ultrasound showed mildly increased vascularity. PTU was started for seronegative Graves’ at 50 mg tid with metoprolol. After 3 days, her FT4 improved to 3.59 ng/dL and TT3 was 176. Further consultation recommended stopping PTU. She was sent home with metoprolol. Her symptoms and FT4 levels improved. FT4 was normal and hCG levels dropped to 54,821 by 18 wks. Discussion: GTT is caused by a transient elevation in T4 due to direct hCG stimulation of the TSH receptor. It is more common with multiple or molar gestations and hyperemesis gravidarum, also mediated by hCG. It typically results in mild thyrotoxicosis, highlighting the uniqueness of this case. Only a couple of case reports exist where GTT presented as severe thyrotoxicosis or thyroid storm and persisted this long. It is critical to distinguish GTT from Graves’ given their different outcomes and treatment. GTT is commonly misdiagnosed as Graves’ as both result in thyrotoxic labs and symptoms and can present in 1st trimester. GTT typically presents at 8-10 wks and lasts until 14-16 wks when hCG levels fall, but Graves’ may also improve by 2nd trimester due to the immune suppression of pregnancy. It is also possible for both to co-exist. hCG levels >100,000 are associated with GTT but due to the variable sialylation of hCG, which changes its affinity to the TSH receptor and half-life, they are unreliable diagnostically. Key clues supporting GTT include no goiter, exophthalmos, or symptoms pre-pregnancy, negative TRAb and TSI, and, notably, a lower T3/T4 ratio compared to Graves’, as seen in this case. To conclude, GTT is often mistaken for Graves’ but inappropriate use of ATDs can result in fetal hypothyroidism and does not improve outcomes. Although the severity of our case is unusual, accurate distinction from Graves’ by endocrinologists is crucial to ensure optimal maternal-fetal outcomes. Presentation: 6/1/2024

12586 A Case Of Ventricular Fibrillation In Thyroid Storm

Abstract Disclosure: A.A. Luzuriaga Chavez: None. N. Aamir: None. J.P. Hidalgo: None. A. Rao: None. N. Patel: None. Thyrotoxicosis is a life-threatening condition caused by an excessive level of circulating thyroid hormones. It can lead to high mortality and morbidity, even if diagnosed and treated in its early stages. Symptoms can include fever, irritability, tachycardia, diarrhea, and seizures. Levothyroxine is a medication commonly used for hypothyroidism, but cases of acute overdose have been reported worldwide. This is a case of a 55-year-old woman who was admitted after a cardiac arrest caused by a possible overdose of 8 mg of levothyroxine. Case presentation:A 55-year-old woman with a history of major depressive disorder was found unconscious by her boyfriend next to a bottle of levothyroxine (which contained a 3-month supply) and was rushed to the emergency department (ED) by EMS. According to the patient's medical chart and family, she did not have a history of hypothyroidism. In the field, she suffered a V-fib cardiac arrest but was successfully resuscitated and brought to the ED. However, she had another cardiac arrest upon arrival but was revived again after 20 minutes. During the physical examination, the patient did not exhibit any signs of thyroid enlargement, exophthalmos, or jaundice. The initial electrocardiogram showed concerning signs of ST-elevation myocardial infarction so the patient was started on heparin drip and continuing amiodarone. The patient was then transferred to the ICU for post-arrest care. Bloodwork revealed TSH <0.005, T3 15.74, and T4 1.57. The Burch-Wartofsky point scale indicated a score of 55, which is consistent with a high suspicion of thyroid storm. The patient's condition continued to worsen, with increasing vasopressor requirements and hyperthermia. Despite the amiodarone drip, the patient's heart rate continued to be less than 100 beats per minute, propranolol could not be started. Furthermore, the patient started bleeding from the nasogastric tube, and the medical team was unable to start any oral propylthiouracil or methimazole. Consequently, they administered hydrocortisone 300 mg, followed by 100mg every 8 hours. The patient was transitioned to comfort care measures. Discussion:Massive ingestion of levothyroxine can lead to excessive thyroid hormone levels and cause sympathetic excitation.Reports of adults ingesting levothyroxine are rare, and those who do generally experience more severe symptoms such as cardiac arrhythmias, malignant hyperthermia, and renal failure. Excessive thyroid hormone levels lead to increased beta adrenergic receptors within the myocardium, rendering it more susceptible to both vagal and sympathetic stimulation. A few isolated case reports show thyrotoxicosis was associated with ventricular fibrillation. Thyroid storm can occur a few days after an overdose of levothyroxine. However, in this case, the patient developed thyrotoxicosis within 6 to 8 hours of ingestion, making it an interesting case to study. Presentation: 6/1/2024

7404 Evaluation Of Cortisol Reserve And Adrenal Imaging In Patients With Graves’ Disease Before And Six Months After Treatment

Abstract Disclosure: P. Sharma: None. S. Mir: None. S. Mohd Patto: None. A.H. Bhat: None. B. Dar: None. M. Bhat: None. Introduction: There is scarcity of data regarding the effect of thyrotoxicosis on cortisol metabolism and adrenal gland size. An increase in cortisol metabolism can deplete the functional reserve of adrenal cortex and lead to adrenocortical insufficiency even when there is no pre-existing Addison's disease. In developing countries patients with Graves’ disease present in advanced states of thyrotoxicosis. Besides they are also exposed to a variety of environmental stresses such as recurrent febrile illnesses, salt, and water loss due to manual labour in hot and humid climates etc., which can precipitate an adrenal crisis in the presence of compromised adrenal reserve. So present study was undertaken to assess cortisol reserve and adrenal gland size in patients with treatment naive Graves' disease. Objectives- The present study, was undertaken to assess cortisol reserve and adrenal imaging in patients with treatment naive Graves' disease. Specific information in this regard would help alert physicians dealing with clinical thyrotoxicosis in developing countries of tropics to the possibility of co-existing adrenal decompensation and adopt appropriate life saving measures promptly. Material & Methods: We examined 38 treatment-naive Graves' Disease patients at GMC, SSH, Srinagar, Kashmir, INDIA. Basal cortisol and cortisol response to ACTH were measured before and after six months of treatment, alongside adrenal CT imaging. Results: In hyperthyroid state, Graves' patients exhibited significantly lower basal cortisol compared to euthyroid and healthy controls (306 vs. 410 vs. 421 nmol/l, p < 0.05). 23.6% patients had subnormal cortisol response to ACTH(250ug). Those with T3 ≥ 400 ng/dl had lower cortisol response (560±133 nmol/l) and delta cortisol response than T3 < 400 ng/dl (724 ± 294 nmol/l, 213+/-73 vs. 428+/-265 nmol/l). After achieving euthyroid state, cortisol levels improved significantly (410±213 nmol/l vs. 306 ± 103 nmol/l, p < 0.05). Adrenal CT scans in 34 patients was done out of which 19 showed statistically significant increases in gland thickness, width, and AP diameter compared to controls (p < 0.01, p < 0.05. Repeat CT in 26 patients demonstrated resolution of hyperplasia (p < 0.05). Conclusion: Treatment-naive Graves' disease patients have compromised adrenocortical reserve and adrenal gland enlargement. Adrenal changes are reversible after achieving euthyroid state. These findings support steroid supplementation in impending thyrotoxic crisis and highlight a unique feature of reversible adrenal gland enlargement in this context. Keywords: Graves’ Disease, Adrenal hyperplasia, Cortisol reserve. Presentation: 6/3/2024

6575 From Tonsils to the Thyroid: A Rare Case of Acute Suppurative Thyroiditis in an Immunocompetent Adult

Abstract Disclosure: F. Sajid: None. A. Mubashir: None. F. Mohsin: None. M. Sattar: None. Introduction: Acute suppurative thyroiditis (AST) is a rare infection of the thyroid gland due to its high vascularity, protective encapsulation, and high iodine content. Most AST cases occur in children with anatomical aberrations or in immunosuppressed adults. Here, we describe a case of AST in an immunocompetent woman. Case: A 54-year-old woman with no medical history presented to the emergency department due to dyspnea, dysphagia, and odynophagia for two days. She reported a four-day history of sore throat, fever, and chills. She was saturating well on room air but was sitting in a tripod position. She had erythema, swelling, tenderness to palpation in the anterior neck with a hoarse voice, and moderate trismus. Nasopharyngoscopy revealed no mass, but the scope could not pass beyond the velum due to edema. The patient’s condition quickly deteriorated, necessitating emergent intubation for acute hypoxic respiratory failure. After intubation, the patient had cardiac arrest with asystole requiring resuscitation and successful ROSC. The initial CT scan showed extensive soft tissue abnormalities in the nasopharynx and parapharyngeal tissues, extending to the thyroid gland and mediastinum with the possibility of developing abscesses. A thyroid ultrasound showed a heterogeneous thyroid gland without nodules or increased vascularity. Treatment commenced with ampicillin-sulbactam. Laboratory results showed Free T4 of 4.74 ng/dL (0.58-1.64), TSH 0.03 MCIU/mL (0.39-4.08), Total T3 1.56 ng/dL (0.72-1.35), WBC 19.3 K/UL (4.8-10.8), and elevated ESR and CRP levels. Thyroid-stimulating Immunoglobulin (TSI), Thyroid Peroxidase (TPO) Antibody, and Thyrotropin Binding Inhibitory Immunoglobulin (TBII) were negative, making AST the top differential. Methimazole was initiated due to concerns of thyroid storm, but it was quickly tapered due to a significant decrease in Free T4 levels and suspicion of AST. A repeat CT scan revealed more defined abscesses along the bilateral pharyngeal walls extending to the thyroid bed. The patient underwent bilateral tonsillectomy and drainage of the abscesses. She was extubated the following day. Cultures from the abscesses grew rare Klebsiella pneumoniae, susceptible to Ampicillin-sulbactam. A barium swallow on day 14 showed no evidence of a pyriform sinus fistula. She was discharged on day 15 with Augmentin for 7 days. On discharge, free T4 decreased to half (2.39 ng/dL), and Total T3 normalized (1.08ng/dL). Conclusion: This case presents a rare instance of AST in an immunocompetent patient without anatomical anomalies, stemming from the spread of peritonsillar and parapharyngeal abscesses into the thyroid bed. AST should be considered in cases of deep neck infections, as it is a potentially life-threatening disease. It is crucial to identify and treat AST early to prevent complications. The primary treatment involves antibiotics, incision, and drainage. Presentation: 6/1/2024

7876 Complex Complications of Thionamide Therapy in One Patient: Methimazole-Induced Agranulocytosis and PTU-Induced ANCA-Vasculitis

Abstract Disclosure: E. Zweibach: None. A. Chang: None. Introduction: Thionamides, including methimazole and propylthiouracil (PTU), are essential for treating Graves' disease but can cause serious side effects such as agranulocytosis and ANCA-vasculitis. Although agranulocytosis itself is quite uncommon, the incidence of ANCA vasculitis is even more infrequent, making combination of conditions particularly exceptional. We present a unique case of a Graves' disease patient who suffered both complications: agranulocytosis due to methimazole and ANCA vasculitis from PTU, with successful resolution of both the clinical signs and laboratory findings following drug discontinuation. Case: 61-year-old female with a history of Graves' disease previously managed with methimazole but discontinued due to agranulocytosis, presented with lower extremity swelling, atrial fibrillation with RVR, and high output cardiac failure. Laboratory tests showed hyperthyroidism (TSH 0.008, Free T4 3.07), leading to a diagnosis of thyroid storm. Patient was started on PTU inpatient and discharged with this medication to home. Eight months later, the patient developed alarming signs including gross hematuria, oral ulcers, widespread muscle pain, found to have AKI with Cr of 2.79 and hospitalized for further eval. While hospitalized, the patient was found to have a range of complications including leukopenia with normal granulocyte count, anemia, AKI, proteinuria, and microscopic hematuria. Rheumatological evaluation showed +ANA and a high ANCA titer >1:1280, along with elevated levels of MPO and PR-3, and reduced complement levels. These symptoms and laboratory findings led to a diagnosis of ANCA vasculitis induced by PTU, resulting in the cessation of this medication. Following the discontinuation of PTU there was a notable improvement with normalization of serum Cr and resolution of proteinuria within 1.5 months. Concurrently, MPO and PR-3 levels began to decrease, and her hematological abnormalities resolved. During this period, her Free T4 levels gradually increased, leading to the administration of radioactive iodine for the treatment of her Graves' disease. Discussion: This case underscores the complexities in treating a patient with Graves' disease highlighting the unpredictable and severe side effects of antithyroid drugs like agranulocytosis and ANCA vasculitis. We report the first documented case of sequential thionamide-induced complications: agranulocytosis with methimazole, followed by ANCA vasculitis with propylthiouracil. Although both can arise from immune responses to these medications, they are distinct in their pathophysiology and are not associated with one another. The unpredictable nature of these side effects complicates prevention. Educating patients to promptly report any unusual symptoms and immediate medical intervention with drug discontinuation are key to managing these adverse reactions effectively. Presentation: 6/1/2024

9196 Establishment of Thyroid Storm Mouse Model and Therapeutic Effects of Ghrelin

Abstract Disclosure: C. Kurimoto: None. Y. Furukawa: None. T. Akamizu: None. A. Doi: None. K. Takeshima: None. S. Morita: None. H. Iwakura: None. H. Ariyasu: None. H. Furuta: None. M. Nishi: None. T. Matsuoka: None. Context: Thyroid storm (TS), a life-threatening condition that can damage multiple organs, is caused by a combination of thyrotoxicosis and severe physical stresses. Infection is the most common triggering factor. Hypercytokinemia is a suggested background, but the pathological condition is unclear and there are no appropriate animal models. Further, TS has limited therapeutic options. Objectives: We aimed to confirm the hypercytokinemia in patients with TS, establish a TS model mouse by triiodothyronine and lipopolysaccharide administration, and explore the therapeutic effects of ghrelin on TS. Methods: We evaluated serum IL-6 levels as a representative marker of hypercytokinemia in patients with TS. As a TS model, C57BL/6 mice were titrated with triiodothyronine and lipopolysaccharide to develop a lethal model with approximately 30% survival at 24 hours. We assessed the survival ratio, mouse sepsis scores and blood biomarkers (IL-6, metanephrine, alanine aminotransferase) and evaluated the effects of ghrelin on these parameters. Results: Serum IL-6 was increased in patients with TS compared with those with Graves' disease without TS (55.7 ± 69.0 vs. 3.13 ± 1.41 pg/mL, P < .05, n=4 each). Next, we titrated the doses of T3 and LPS, aiming to achieve a survival rate of approximately 30% at 24 hours after administration. Two out of five mice in the T3 3.0 mg/kg group died, while none of the eight mice in the T3 1.0 mg/kg group died. Therefore, we determined that the appropriate T3 dose for the TS mouse model is 1.0 mg/kg, which is not lethal when administered alone. In the T3 1.0 mg/kg group (n=8), serum FT3 levels were approximately three times higher (15.3 ± 4.5 vs. 4.5 ± 0.7pg/ml) than those in the control group (n=8). Next, different doses of LPS was added to the T3 group. Survival at 24 hours post-dose was 60% in the T3 + LPS 0.2 mg/kg group (n=5) and 33% in the T3 + LPS 0.5 mg/kg group (n=5), while survival was 100% in the LPS 0.5 mg/kg alone group (n=5),. Based on these findings, the dosage for the murine TS model was determined to be “triiodothyronine 1.0 mg/kg and lipopolysaccharide 0.5 mg/kg”. This TS model group had increased mouse sepsis score, serum IL-6, metanephrine and alanine aminotransferase. In this model, the ghrelin at 300 µg/kg improved the survival rate to 66.7% (P < .01, vs. 0% [saline-treated group]) as well as the mouse sepsis score, and it decreased the serum IL-6 and metanephrine. Conclusion: We confirmed the hypercytokinemia in patients with TS. Next, we established a lethal model simulating TS by inducing “thyrotoxicosis” by exogenous administration of thyroid hormones, and by inducing “sepsis” by intraperitoneal administration of LPS. The model mice exhibited similar pathophysiological status to human TS associated with induction of serum IL-6 and other biomarkers, which were improved by ghrelin. Presentation: 6/1/2024

9370 Thinking Outside the Box: A Rare Case of Using Plasmapheresis Treatment of Amiodarone-Induced Thyrotoxicosis in Preparation For CABG

Abstract Disclosure: K. Shaik: None. A. Kartoumah: None. J. Alsheikh: None. A. Nayeem: None. M.H. Horani: None. Introduction: Amiodarone, a standard treatment for arrhythmias, poses a risk of disrupting thyroid function and causing amiodarone-induced thyrotoxicosis (AIT). In critical cases where AIT is refractory to first-line treatment, plasmapheresis can be a vital option to rapidly lower thyroid hormone levels, which is essential for pre-surgical stabilization. This case report describes plasmapheresis in managing AIT in a patient undergoing coronary artery bypass grafting, highlighting its role in preventing potential thyrotoxic crises. Case Presentation: A 75-year-old male with a past medical history of diabetes mellitus, coronary artery disease, arrhythmias treated with amiodarone, and a ninety-pack-year history of tobacco presented to the ED with complaints of chest pressure and dyspnea. Initial troponin levels were normal at 24 ng/mL but trended upward toward 66 ng/mL. In the ED, he was not tachycardic and denied recurrent pain, fever, or chills. A CT angiogram of his chest showed no pulmonary embolus. The patient was found to have low TSH (0.005), and his T3 and T4 were both elevated (3.89/1.96, respectively), confirming thyrotoxicosis; however, he was negative for Graves’ disease. While in the hospital, his amiodarone was discontinued, and he was started on prednisone 10 mg for 14 days and methimazole 5 mg for 14 days. He was ultimately discharged on the same prednisone and methimazole regimen and told to follow up with outpatient endocrinology. However, the patient reappeared a week later with dyspnea on exertion; blood work performed after admission revealed a higher free T4 at 2.87. The patient was admitted, and angiography showed three-vessel disease; however, a coronary artery bypass graft (CABG) procedure was delayed over the concern of a potential thyroid storm. Thus, CABG was planned for when free T4 was less than 2, and the patient underwent two rounds of plasmapheresis, which initially decreased free T4 to 1.7 and finally to 1.4. Ultimately, a CABG was performed and well tolerated. Discussion: Amiodarone-induced thyrotoxicosis (AIT) poses a challenge in patient management, especially in patients requiring urgent surgeries. Plasmapheresis is shown to be a valuable option for rapidly lowering thyroid hormone levels and stabilizing the patient in the pre-operative stages. This case demonstrates the effectiveness of plasmapheresis in reducing free thyroxine levels, facilitating a safe and successful CABG. Due to its ability to quickly remove circulating thyroid hormones, plasmapheresis has excellent potential in managing refractory AIT. It is crucial to carefully time plasmapheresis relative to surgery and monitor for complications throughout. Further research is required to optimize proper plasmapheresis protocols in AIT. Conclusion: This case study highlights plasmapheresis as a promising adjunctive therapy in managing AIT and preventing potential thyrotoxic crises. Presentation: 6/1/2024