When A Toxic Thyroid Makes The Liver Toxic: A Case Of Thyroid Storm Complicated By Acute Liver Failure

ABSTRACT Objective: Thyroid storm is a rare life-threatening medical emergency. It is associated with high mortality (10 to 30%). Though there may be mild derangements in liver function tests (LFTs), acute liver failure (ALF) is infrequently reported and its pathophysiology is poorly understood. We hereby report a case of ALF in a patient with thyroid storm. Methods: A 41-year-old female with history of Graves disease (non-compliant with treatment) complicated by multiple episodes of thyroid storm and atrial fibrillation (Afib) presented with exertional dyspnea and productive cough. She was found to be in Afib with rapid ventricular rate and new-onset cardiomyopathy (left ventricular ejection fraction of <20%). She was noted to have a large, non-tender thyroid gland with bruit; thyroid function tests were consistent with uncontrolled hyperthyroidism. Results: Two days after initiating treatment with methimazole and propranolol, she became increasingly lethargic, confused, and developed asterixis and icterus. LFTs were consistent with ALF. Methimazole was stopped due to potential hepatotoxicity. Steroids, cholestyramine, and Lugol iodine were started for thyroid storm. Liver ultrasound showed heterogeneous liver texture consistent with acute inflammation. The patient subsequently improved with conservative management and control of thyroid storm. Once clinically stable, she underwent thyroidectomy as a definitive treatment of her Graves disease. Conclusion: The occurrence of ALF in patients with thyroid storm has rarely been reported in the literature and is associated with high mortality. Hyperthyroidism has been hypothesized to injure the liver through several mechanisms which we will discuss in this case report. Abbreviations: ALF acute liver failure; LFTs liver function tests