Introduction: Altered mental status (AMS) is a common symptom in patients with liver disease with a wide list of differential diagnoses. Knowledge of etiologies of AMS unique to patients with hepatic dysfunction is vital in order to help recognize, diagnose, and treat the underlying cause in a timely manner.
Case Description/Methods: A 46-year-old man with a history of recent COVID infection was transferred to our hospital for further evaluation of acute liver injury and AMS. On arrival, his labs were notable for AST of 408 U/L, ALT of 620 U/L, ALP of 5942 U/L, TB of 11.0 mg/dL, and an INR of 1.1. His work-up included an MRCP that showed segmental biliary ductal dilation with associated restricted diffusion and peribiliary enhancement concerning for sclerosing cholangitis. ERCP revealed a 3cm biliary cast that was removed and noted diffuse rarefaction of ducts throughout the entire biliary tree. A liver biopsy revealed centrizonal cholestasis with portal-based bile ductular reaction and mild bile duct injury. Despite adequate treatment of suspected infection and hepatic encephalopathy, his AMS persisted. His basic metabolic panel (BMP) was notable for Na of 143 mEq/L. A send-out lipid panel that was obtained to work-up his dyslipidemia revealed a total cholesterol of 1018 mg/dL, triglycerides of 420mg/dL, and the presence of lipoprotein X. A venous blood gas (VBG) was obtained showing a Na of 157 mEq/L and serum osmolality was 322 mmol/kg, confirming true hypernatremia. He was slowly treated with hypotonic solutions with significant improvement in his mentation. On follow-up one year later, he has persistent cholestasis and is currently being considered for liver transplant.
Discussion: The final diagnosis was COVID-related ischemic cholangitis and disappearing bile ducts with persistent cholangiopathy, presenting with severe cholestasis, accumulation of lipoprotein X, and pseudonormonatremia. When faced with severe cholestatic liver disease, clinicians should keep in mind the possibility of accumulation of lipoprotein X and its association with hyperviscosity and spurious electrolyte abnormalities. Clinicians should rely on obtaining blood gas analyses for accurate electrolyte measurement in such cholestatic patients as blood gas analyses utilize direct ion-sensitive electrodes (ISE) to measure electrolytes, whereas routine basic metabolic panels utilize indirect ISE that are liable to spurious results in the presence of hyperlipoproteinemia/lipoprotein X.
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