Mechanisms, Risks, and New Treatment Options for Hyponatremia

Abstract

Hyponatremia is the most common electrolyte abnormality in hospitalized patients and is associated with increased mortality, morbidity, and longer hospital stays. Because patients with this disorder are often asymptomatic, hyponatremia is frequently undiagnosed and untreated. Serious neurologic complications may ensue when hyponatremia develops too rapidly or the serum sodium concentration ([Na⁺]) falls below 120 mEq/l. Hypotonic dilutional hyponatremia is the most common form of this disorder, which may present as euvolemic [e.g., due to failure to suppress secretion of arginine vasopressin (AVP)] or hypervolemic (due to edema-forming conditions such as heart failure). Hypovolemic hyponatremia is due to conditions promoting renal or extrarenal sodium loss. Because AVP, which is intimately involved in regulating osmolar homeostasis, is often elevated in patients with hypervolemic and euvolemic hyponatremia, treatments that directly target the effects of this hormone may provide a more predictable correction of serum [Na⁺] than those traditionally used. The AVP receptor antagonists (conivaptan, tolvaptan, lixivaptan, and satavaptan) are a new class of agents that have been shown to normalize serum [Na⁺] by promoting aquaresis – the electrolyte-sparing excretion of free water.

Hyponatremia as a prognostic and predictive factor in metastatic renal cell carcinoma

“…This is despite hyponatremia is the most common electrolyte disorder in hospitalised patients (Asadollahi et al, 2007;Patel and Balk, 2007). However, within the last few years, a large body of evidence has emerged rendering hyponatremia as a strong general danger signal in many disorders as liver cirrhosis (Luca et al, 2007;Kim et al, 2008), congestive heart failure Rossi et al, 2007;Ghali, 2008;Gotsman et al, 2008;Rusinaru et al, 2009), infections (Nair et al, 2007;Yaghoubian et al, 2007;Chao et al, 2008), and several cancers (Gandhi and Johnson, 2006;Kim et al, 2007;Huo et al, 2008;Kacprowicz and Lloyd, 2009). Thus, hyponatremia may in fact be an important universal danger signal and an indicator of poor prognosis.…”

“…Until recently, no predictive or prognostic role of low serum sodium has been recognised. This is despite hyponatremia is the most common electrolyte disorder in hospitalised patients (Asadollahi et al, 2007;Patel and Balk, 2007;Ghali, 2008). However, hyponatremia is associated with poor outcome in several medical conditions, such as liver cirrhosis (Luca et al, 2007;Kim et al, 2008), congestive heart failure Rossi et al, 2007;Gotsman et al, 2008;Rusinaru et al, 2009), and infectious diseases as pneumonia (Nair et al, 2007), childhood meningitis (Chao et al, 2008), and necrotising soft-tissue infection (Yaghoubian et al, 2007).…”

Role of BKβ1 in Na+ reabsorption by cortical collecting ducts of Na+-deprived mice

“…BK channel; maxi K; mineralocorticoids; adrenal cortex; potassium secretion HYPONATREMIA, the most common electrolyte abnormality in hospitalized patients, is associated with increased mortality and morbidity. Hyponatremia is frequently undiagnosed and untreated because patients are often asymptomatic (13). Most cases of hyponatremia are associated with excessive levels of antidiuretic hormone (ADH or arginine vasopressin), resulting in hypervolemia.…”

The Syndrome of Inappropriate Antidiuresis: Pathophysiology, Clinical Management and New Therapeutic Options

“…However, it seems that this strategy could be effective only during the acute phase of correction, since few results of long-term treatment have been reported [49]. Therapeutic options for SIAD also include treatments which actually are not widely used in routine clinical practice.…”