Hyponatremia is defined by a level of Na in serum below or equal to 136 mEq/L while in hepatic cirrhosis it is classically considered as relevant only at a level of Na below 130 mEq/L.
Hyponatremia frequently occurs in patients with end-stage hepatic disease. The frequency and severity are variable but it has been estimated that it occurs with a frequency of 57% in hospitalized patients with cirrhosis and in those on waiting lists for hepatic transplants. Signs and symptoms of hyponatremia are related to dysfunctions of the central nervous system, due to migration of the water from intravascular space to the brain cells, resulting in the occurrence of cerebral edema. Therapeutic options in hyponatremia are limited and are based on restriction of water consumption, exclusion of diuretics and vaptans. Hepatic transplant remains the only definitive treatment for end-stage hepatic diseases in which hyponatremia has occurred.