The Utility of Tolvaptan in the Peri-operative Management of Severe Hyponatremia During Liver Transplantation: 2179

Hyponatremia is a common finding in cirrhotic patients and is one of the steps in a cascade of worsening hemodynamic dysfunction. Hyponatremia increases peri-operative risk of central pontine myelinolysis (CPM), cerebral edema, and seizures as well as short-term mortality following liver transplantation. Therefore, it is critical to correct hyponatremia prior to liver transplant. We present a case of a patient with cirrhosis and severe hyponatremia. Administration of tolvaptan corrected his hyponatremia and he underwent successful liver transplantation. A 50 year-old male with cirrhosis due to Hepatitis C with recurrent variceal bleeding and refractory ascites was referred to our center for transplant evaluation. His Model for End-Stage Liver Disease (MELD) score was 17. While awaiting liver transplant he had multiple hospitalizations for hepatic encephalopathy and severe symptomatic hyponatremia. Serum sodium reached a nadir of 113 mg/dL despite free water restriction and holding diuretics. Serum creatinine rose from a baseline of 1 to 1.5 mg/dL, raising concern for hepatorenal syndrome (HRS). Liver function gradually worsened and MELD score peaked at 27. The patient was started on tolvaptan 15mg daily for three days for hyponatremia, and albumin 25g IV daily, octreotide 100 mcg subcutaneously three times daily, and midodrine 10mg orally three times daily for Type II HRS. Within two weeks his renal function normalized and his serum sodium trended up to >130 mg/dL. He underwent successful orthotopic liver transplant. Post-operatively his serum sodium levels remained above 130 mg/dL and he was discharged from the hospital in good condition, with no complications six months post-transplant. Hyponatremia is a common finding in cirrhosis, occurring in approximately 30% of hospitalized patients and 40-60% of patients with refractory ascites or HRS. In addition to increasing mortality prior to liver transplant, hyponatremia increases post-transplant complications including CPM, infection, renal dysfunction, and prolonged hospital stays. We report a case of the successful use of tolvaptan to correct severe hyponatremia leading to an uncomplicated liver transplant. Vaptans are vasopressin 2 receptor antagonists that decrease aquaporin synthesis and insertion in the collecting ducts leading to decreased free water absorption. We suggest that tolvaptan can be a valuable tool as a bridge to liver transplant in the cirrhotic patient with severe hyponatremia.