Hypervolemic Hyponatremia (Liver).

Hyponatremia is a frequent complication in patients with advanced cirrhosis. Patients with cirrhosis can develop two types of hyponatremia, hypovolemic or hypervolemic (dilutional) hyponatremia. Hypervolemic hyponatremia is the most common type and it develops as a consequence of an impairment in the renal capacity to eliminate solute-free water. The key mechanism leading to solute-free water retention is a non-osmotic hypersecretion of vasopressin (AVP), secondary to a reduction in effective arterial blood pressure existing in patients with advanced cirrhosis. Hypervolemic hyponatremia is associated with increased morbidity and mortality in patients with cirrhosis, and it has also been associated with increased complications after liver transplantation. Currently, the management of hypervolemic hyponatremia in cirrhosis is based on fluid restriction. Vaptans, oral selective vasopressin V2-receptor antagonists, and particularly tolvaptan, have been investigated as a pharmacological approach for the management of hypervolemic hyponatremia in cirrhosis. However, existing information on its efficacy in cirrhosis is still scarce and a recent warning has been raised about their potential role on inducing liver injury at high doses.