1.0 Sodium Excess: Hypernatremia

Hypernatremia

_________ is a serum sodium level higher than 145 mEq/L (145 mmol/L). It can be caused by a gain of sodium in excess of water or by a loss of water in excess of sodium.

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PATHOPHYSIOLOGY

1. A common cause is fluid deprivation in patients who do not respond to thirst.

2. Administration of hypertonic enteral feedings without adequate water supplements lead to hypernatremia, as does watery diarrhea, and greatly increased insensible water loss through the lungs or skin (e.g., hyperventilation, burns).

3. Diabetes insipidus, which is a lack of ADH due to posterior pituitary dysfunction, can lead to lack of adequate reabsorption of water into the bloodstream at the level of nephron.

4. Less common causes are heatstroke, nonfatal drowning in seawater (which contains a sodium concentration of approximately 500 mEq/L), and malfunction of hemodialysis or peritoneal dialysis systems.

5. IV administration of hypertonic saline or excessive use of sodium bicarbonate.

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• A lack of normal sodium level in the bloodstream, either hypernatremia or hyponatremia.

• In performance athletes who lose excessive water via perspiration, sodium can be concentrated in the bloodstream. This can lead to these life-threatening conditions: Encephalopathy, Confusion, Disorientation, and Stupor.

• In performance athletes who lose excessive sodium via perspiration during exercise can lead to excess sodium depletion from the bloodstream. This can manifest as: Confusion, Disorientation, and Stupor

• Testing of the blood and urine can differentiate hyponatremia from hypernatremia, determine the severity of the dysnatremia, and guide appropriate therapy.

• Altered cerebral function

• agitation, confusion, seizure

• lethargy, stupor, coma

CLINICAL MANIFESTATION

• Central Nervous System

  • -

  • Normovolemia/hypovolemia

  • Hypervolemia:

• Dry skin and tongue

• Presence/absence of edema

CLINICAL MANIFESTATION

• Integumentary

145 mEq/L

Increased

CLINICAL MANIFESTATION

• Integumentary

  • Serum sodium: <____

  • _____ urine specific gravity

Hypotonic Solution (0.45% NaCl)

Isotonic non-saline (Dextrose 5% in water)

Hypotonic sodium chloride solution

Desmopressin acetate

MEDICAL MANAGEMENT

• Gradual lowering of the serum sodium level by the infusion of a _______ (e.g.,______) or an _________(e.g., _______).

2. _____ can be used when water needs to be replaced without sodium. However, 0.45% NaCl is thought to be safer than D5W because it allows a gradual reduction in the serum sodium level.

3. _________ is the IV solution of choice in severe hyperglycemia with hypernatremia.

4. Diuretics can be prescribed to treat the excess sodium.

5. ________, a synthetic ADH, may be prescribed to treat diabetes insipidus if it is the cause of hypernatremia.

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NURSING MANAGEMENT: PREVENTING HYPERNATREMIA 

1. Provide oral fluids at regular intervals, particularly in patients who are unable to perceive or respond to thirst.

2. If enteral feedings are used as an alternative route for intake, sufficient water should be given to keep the serum sodium and BUN within normal limits.

3. Some herbal medications can also increase serum sodium levels.

4. Adequate water intake must be ensured for patients with DI.

5. If the patient is alert and has an intact thirst mechanism, merely providing access to water may be sufficient.

6. If the patient has a decreased LOC or other disability interfering with adequate fluid intake, parenteral fluid replacement may be prescribed.

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NURSING MANAGEMENT: CORRECTING HYPERNATREMIA 

• Monitor the patient’s response to the infusion of fluids by reviewing serial sodium levels and by observing for changes in neurologic status, such as confusion, disorientation, and possible decreased LOC.

• A gradual decrease in the serum sodium level will improve neurologic status.

• Rapid reduction in the serum sodium level renders the plasma temporarily hypoosmotic compared to the intracellular fluid within the brain cells.