Skip to Main Content

Content Update

February 1, 2019

Normal saline versus balanced fluids for volume resuscitation: A long-standing controversy has been the relative benefits of 0.9% normal saline versus balanced intravenous crystalloids (lactated Ringer's and Plasma-Lyte A). Accumulating observational data increasingly suggests that the hyperchloremic metabolic acidosis associated with the administration of large volumes of saline leads to increased rates of acute kidney injury and need for dialysis. Two recent, large, randomized trials (SMART and SALT-ED) have attempted to answer this question in both critically ill and in non-critically ill patient populations. Although the question is not yet definitively resolved, these studies further suggest that major adverse kidney events are more frequently seen in patients resuscitated with normal saline.



  • image Blood volume and serum osmolality which are essential for normal cellular function are tightly regulated in the human body. Water balance determines the serum sodium concentration, and sodium balance determines water status.

  • image Hypovolemic hypotonic hyponatremia is relatively common in patients taking thiazide diuretics; however, thiazide-induced hyponatremia is usually mild and relatively asymptomatic.

  • image Euvolemic (isovolemic) hyponatremia is most often caused by the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Common causes of SIADH include certain cancers, central nervous system (CNS) and pulmonary disorders, and some drugs.

  • image Symptoms of hypo- or hypernatremia are usually neurologic and range from weakness, lethargy, restlessness, irritability, twitching, and confusion to seizures, coma, and death. Symptom severity depends on both the magnitude of the change in the serum sodium concentration and the rate at which it changes.

  • image Treatment goals in patients with either hypo- or hypernatremia should include cautious correction of the serum sodium concentration and, when appropriate, restoration of a normal extracellular fluid (ECF) volume. Too rapid correction of the serum sodium can result in cerebral edema, seizures, neurologic damage, osmotic demyelination syndrome, and possibly death. To minimize the risk of these complications, the serum sodium concentration should be corrected at a rate not to exceed 6 to 12 mEq/L (mmol/L) in 24 hours, depending on the rate of change in the serum sodium concentration.

  • image Asymptomatic or mildly symptomatic hyponatremia should be managed conservatively with treatment directed at the underlying cause. Intravenous (IV) infusion of 0.9% sodium chloride (NaCl) is most often used to correct the serum sodium concentration in patients with hypovolemic hypotonic hyponatremia and moderate to severe symptoms. A 3% NaCl infusion may be used cautiously in patients with moderate to severe symptoms and euvolemic or hypervolemic hypotonic hyponatremia (along with a loop diuretic).

  • image Hypernatremia is always hypertonic and most commonly occurs when increased water or hypotonic fluid losses are not offset by increased water intake.

  • image Hypovolemic hypernatremia is relatively common in patients taking loop diuretics. After symptoms of hypovolemia are corrected with 0.9% NaCl, the free water deficit should be replaced.

  • image Patients with central diabetes insipidus (DI) can be treated with desmopressin acetate, with a goal to decrease urine volume to less than 2 L per day while maintaining a ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.