Hyponatremia overview: Difference between revisions
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==Pathophysiology== | ==Pathophysiology== | ||
Hyponatremia is defined as serum [[sodium]] less than 135 mEq/L (mmol/L). Sodium is the major [[electrolyte]] which determines serum [[osmolality]]. [[Hyponatremia]] is a water balance disorder in which the ratio between sodium and water is disturbed. Water homeostasis is regulated mainly by two organs: [[hypothalamus]] by [[ADH]] secretion and thirst, kidney by water reabsorption or excretion. [[ADH]] is secreted due to alteration in serum osmolality or intravascular volume. Mechanisms in which different [[Hyponatremia causes#Causes|disorders]] cause hyponatremia involve [[ADH]] (secretion or action) and kidney function ( absorption or excretion). [[ADH]] secretion is increased by increased osmolality of serum or decreased effective intravascular volume. | |||
==Causes== | ==Causes== | ||
Revision as of 18:40, 7 June 2018
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Hyponatremia Microchapters |
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Diagnosis |
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Treatment |
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Case Studies |
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Hyponatremia overview On the Web |
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American Roentgen Ray Society Images of Hyponatremia overview |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Saeedeh Kowsarnia M.D.[2]
Overview
Historical Perspective
In 1858, Claude Bernard, French physiologist first proposed a direct relationship between the central nervous system and renal excretion of osmotically active solutes. In 1913, Jungmann and Meyer in Germany induced polyuria and increased urinary salt excretion in animals through medullary lesion. In 1950, Peters, Welt, and co-workers described few patients with encephalitis, hypertensive intracranial hemorrhage, and bulbar poliomyelitis who presented with severe dehydration and hyponatremia.
Classification
Hyponatremia (serum sodium less than 135 mEq/L) may be classified based upon serum ADH level, duration of hyponatremia, serum osmolality and volume status. The various classification systems enable accurate identification of the cause of hyponatremia and hence translate into optimal management based on the condition of the patient.
Pathophysiology
Hyponatremia is defined as serum sodium less than 135 mEq/L (mmol/L). Sodium is the major electrolyte which determines serum osmolality. Hyponatremia is a water balance disorder in which the ratio between sodium and water is disturbed. Water homeostasis is regulated mainly by two organs: hypothalamus by ADH secretion and thirst, kidney by water reabsorption or excretion. ADH is secreted due to alteration in serum osmolality or intravascular volume. Mechanisms in which different disorders cause hyponatremia involve ADH (secretion or action) and kidney function ( absorption or excretion). ADH secretion is increased by increased osmolality of serum or decreased effective intravascular volume.