Patient with Myxedema Coma and Subsequent Iatrogenic Thyrotoxicosis - Role of COVID-19 Pandemic

ABSTRACT

Introduction: Myxedema coma is a rare presentation of severe hypothyroidism. The low incidence of this life-threatening disease may be attributed to easy availability of TSH testing and thyroid hormone replacement therapy. Well documented cases of thyroiditis and thyrotoxicosis due to SARS-CoV-2 are now available in medical literature. Additionally, COVID-19 pandemic has also caused higher rates of non-compliance with medications and appointments. This has resulted in higher rates of exacerbations of most chronic illnesses, including thyroid diseases. We present a case of myxedema coma and subsequent iatrogenic hyperthyroidism during the COVID-19 pandemic. Clinical Case 57-year-old male with paroxysmal atrial fibrillation, CHF, CKD stage IV, type 2 diabetes mellitus, hypertension, and post ablative hypothyroidism was found unresponsive at home. Initial vitals were temperature 95.1F, HR 52 beats per minute, RR 14 breaths per min, BP 90/62 mmHg, and glucose 68 mg/dL. There was no evidence of goiter, and he had generalized edema. Initial labs showed hyponatremia, elevated CPK, TSH 111uIU/mL (0.27-4.2 uIU/mL) and free T4 was <0.1 ng/dL (0.93-1.7 ng/dL). He was intubated, needed vasopressor support, and was treated with empiric antibiotics. He was diagnosed with myxedema coma which was treated with 200 mcg IV levothyroxine, and stress dose hydrocortisone. He was extubated on day 4 of hospital admission after which oral levothyroxine 275 mcg daily was initiated, and steroids were tapered off. Patient's pharmacy confirmed that Levothyroxine was not last filled more than eight months ago. Patient was hospitalized 3 weeks later for pneumonia and Levothyroxine dose was further increased to 300 mcg due to persistently elevated TSH levels. Three months later, patient was admitted for Atrial fibrillation in rapid ventricular response with difficult to control tachycardia. His TSH was 0.01 uIU/mL and thyroxine of 1.93 ng/dL despite not taking any medication for 2 weeks. He admitted to not following up with endocrinologist due to the surge in COVID-19 cases. Dose of levothyroxine was decreased to weight-based dose of 225 mcg, and patient discharged with instructions to repeat labs in 6 weeks and follow up with a clinical provider. Conclusion: This case highlights the consequences of under and over replacement of thyroid hormone. Viral illnesses including SARS-CoV-2 can precipitate myxedema coma in patients with severe hypothyroidism. A high index of suspicion is needed to treat this disease in a timely manner. Providers must make allowances for the limitations in our system to function in a pandemic. Prescribing extra medication refills and offering virtual medicine appointments may help lower hospitalizations. Also, understanding the effect of non-thyroidal illness on thyroid function tests and knowing that TSH takes six weeks to normalize after starting/ adjusting thyroid hormone dose will avoid premature adjustment in hormone doses.Presentation Saturday, June 11, 2022 100 p.m. - 300 p.m.