Diagnosis and Management of Disorders of Body Tonicity—Hyponatremia and Hypernatremia: Core Curriculum 2020

Abstract

Overall body fluid concentration is regulated within a narrow range by the concerted action of the hypothalamic-pituitary axis to influence water intake through thirst and water excretion via the effect of vasopressin, or antidiuretic hormone, on renal collecting duct water permeability. Sodium is the principal extracellular cation; abnormalities in overall effective body fluid concentration, or tonicity, manifest as disturbances in serum sodium concentration. Depending on its severity and chronicity, hyponatremia can lead to significant symptoms, primarily related to central nervous system function. Failure to correct hyponatremia can lead to permanent neurologic damage, as can over rapid correction. It is thus essential to stay within specific limits for correction, particularly for chronic hyponatremia. Hypernatremia also leads to central nervous system dysfunction, although goals for its correction rate are less well established. This Core Curriculum article discusses the normal regulation of tonicity and serum sodium concentration and the diagnosis and management of hypo-and hypernatremia.

Síndrome cardiorrenal: clasificación, fisiopatología, diagnóstico y tratamiento. Una revisión de las publicaciones médicas

“…Los diuréticos de asa son el pilar del tratamiento descongestivo. Hacen posible una potente diuresis al promover la eliminación de sodio y cloro y al mismo tiempo provocan una disminución de la tonicidad en la médula renal, por lo que reducen la capacidad de reabsorción de agua en el túbulo colector, incluso con la posibilidad de contribuir al desarrollo de hipernatremia 34,46 . Un metaanálisis encontró que la torsemida es mejor que la furosemida debido a su mayor vida media, biodisponibilidad oral y quizá su capacidad para bloquear al SRAA, pero falta confirmar estos beneficios en el contexto de IC agudizada 47 .…”

Sodium disorders

“…Los síntomas atribuibles directamente a la hiponatremia se producen principalmente con agudas y marcadas reducciones en la concentración de Sodio en suero y reflejan una disfunción neurológica inducida por edema cerebral. El edema cerebral inducido por hiponatremia ocurre principalmente con reducciones rápidas de la concentración sérica de Sodio, generalmente menos de 24 horas (6,7) (gráfico 1 y 2, tabla 1).…”

Hyponatremia in Patients with Hematologic Diseases

“…Vaptans-drugs which promote water diuresis-are indicated as second-line therapy for hyponatremia related to hypervolemic or euvolemic hyponatremia due to SIADH [188]. Importantly, vaptans should not be used in hypovolemic hyponatremia or together with hypertonic saline solution owing to case reports of associated ODS [186,187,192]. Edematous hyponatremia, in the context of severe acute or chronic kidney injury generally, requires dialysis.…”