2014-18 Delayed correction of hyponatremia can perpetuate ebral edema and result in irreversible neurologic damage and death In contrast, too rapid correction can result in the nd recovery in nonfatal cases is either slow incomplete, often with irreversible residual Acute Hypotonic Hyponatremia Chronic Hyponatremia (<24 to 48 hours) symptoms such as seizure consciousness, correction odium concentration should not exceed 8 reach a target sodium concentration. e first 24 hours in euvolemic patients The desired rise in sodium concentration should not exceed 2 mmol /L/hour, and the total increase in sodium concentration during the first 12 to 24 hours of treatment should not exceed 12 mmol/L Normovolemic hyponatre Hypovolemic Hypotonic Hyponatrer In patients with normovolemic hyponatremia the appropriate therapeutic approach is to address the underlying disease Water restriction lium concentration in the setting of extrarenal fluid Great caution should be exercised in the administration of a brisk and rapid decrease in urine osmolality 72014-1-8 7 • Delayed correction of hyponatremia can perpetuate cerebral edema and result in irreversible neurologic damage and death. • In contrast, too rapid correction can result in the osmotic demyelination syndrome, which can be fatal, and recovery in nonfatal cases is either slow or incomplete, often with irreversible residual neurologic sequelae Acute Hypotonic Hyponatremia (<24 to 48 hours) • If patient is accompanied by severe neurologic symptoms such as seizures or decreased level of consciousness, correction should be rapid and should reach a target sodium concentration. • The desired rise in sodium concentration should not exceed 2 mmol/L/hour, and the total increase in sodium concentration during the first 12 to 24 hours of treatment should not exceed 12 mmol/L. Chronic Hyponatremia • In such cases, the targeted rate of increase in sodium concentration should not exceed 0.5 mmol/L/hour, and the total rise in sodium concentration should not exceed 8 mmol/L in the first 24 hours • Water restriction is helpful in euvolemic patients Normovolemic hyponatremia • In patients with normovolemic hyponatremia, the appropriate therapeutic approach is to address the underlying disease • Water restriction • V2 receptor antagonist Hypovolemic Hypotonic Hyponatremia • When hypovolemia is clearly evident, administration of volume repletion in the form of isotonic saline is the treatment of choice – appropriate clinical history, – orthostatic hypotension, – low urine sodium concentration in the setting of extrarenal fluid losses, – elevated plasma urea and uric acid concentrations • Great caution should be exercised in the administration of isotonic saline to these patients because sometimes the administration of small volumes of isotonic saline can induce a brisk and rapid decrease in urine osmolality