Session 7

NURSING AND MEDICAL APPROACHES TO 

ELECTROLYTE DISTURBANCES

Sodium Imbalances

Disturbances in sodium balance occur frequently in clinical situations and can manifest itself under simple and complex circumstances. Because sodium is the most abundant electrolyte in the ECF it is the primary determinant of the ECF osmolarity. Sodium is the primary regulator of the ECF volume because it is the controlling factor of water distribution. Sodium also functions in regulating the muscle and nerve impulses.

Sodium Deficit (Hyponatremia)

Medical Approach

Etiology

1.     The condition of hyponatremia exists when the serium sodium level is below 135mEq/L.

2.    Sodium is the major cation of the ECF and is the primary determinant of ECF osmolarity; therefore imbalances of sodium usually are associated with imbalances of fluid volume.

3.    Plasma sodium concentration represents the ratio of total body sodium to total body water.

4.    Hyponatremia is one of the most common electrolyte imbalances that occurs in hospitalized clients.

Causes

1.    Causes of hyponatremia are categorized on the basis the effect on the ECF volume.

·      Increased ECF volume hyponatremia is caused by cardiac failure, hepatic failure, near-drowning in fresh water, and tap water enemas, or irrigation of gastric tubes with water instead of  normal saline (NS).

·      Decreased ECF volume hyponatremia is caused by blood loss, excessive wound drainage, diarrhea, use of diuretics, and adrenal insufficiency (Addison’s disease).

·      Normal ECF volume hyponatremia is caused by excessive diaphoresis replaced only with water, hyperglycemia, hyperlipidemia, and the syndrome of inappropriate antidiuretic hormone (SIADH).

 2.  SIADH is a type of hyponatremia associated with overproduction of ADH. Associated disturbances      

of  this condition are:

·  Excessive ADH activity with water retention and dilutional hyponatremia.

·  Inappropriate urinary excretion of sodium in the presence of hyponatremia.

·  SIADH is caused by either over secretion of ADH by the hypothalamus or production of an ADH-like substance from a tumor such as oat-cell lung tumors, head injuries, endocrine and pulmonary disorders, and use of certain medications.

Clinical Manifestations of Hyponatremia

1.    Clinical manifestation of hyponatremia depend on the cause, magnitude, and speed with which the deficit occurs. In general, the more acute the decrease in serum sodium level, the more severe the symptoms with an associated higher mortality rate than with a more slowly developed hyponatremia.

2.    Signs and symptoms of mild hyponatremia include nausea, abdominal cramps, muscle weakness, and behavioral changes. Clients at risk for mild hyponatremia include athletes, individuals who perform heavy labor or strenuous physical activity, and individuals exposed to high environmental temperatures for extended period of time.

3.    Signs and symptoms of more severe hyponatremia are related to the cellular swelling and cerebral edema caused by acute pulling of water into the cells secondary to a dense concentration of sodium present. As the serum sodium level drops below 115 mEq/L, signs of increasing ICP, such as lethargy, confusion, muscular twitching, focal weakness, hemiparesis, papilledema, and seizures may occur.

Management of Hyponatremia

1.    Sodium replacement is the obvious treatment for hyponatremia. This is accomplished orally, by nasogastric tube (NG tube), or parenterally (IV).

2.    In SIADH, hypertonic saline alone cannot change the plasma sodium concentration because the excess sodium would be rapidly excreted in the highly concentrated urine. With the addition of a diuretic such as furosemide (Lasix), urine is not concentrated and isotonic urine can be excreted achieving a change in water balance.

3.    Water restriction is the treatment of choice when normal or excess fluid volume is present. It is also much safer than the treatment of sodium administration and is usually quite effective.

Nursing Approach

Nursing Assessment

It is important to identify clients at risk for hyponatremia so that they can be monitored. Early detection and treatment are important in order to prevent serious consequences.

1.    For clients at risk, the nurse monitors fluid intake and output as well as daily body weight. Abnormal losses of sodium or gains of water are noted.

2.    Gastrointestinal manifestations are also monitored and noted, such as anorexia, nausea, vomiting and abdominal cramping.

3.    Particular attention needs to be given to central nervous system changes., such as lethargy, confusion, muscular twitching, and seizures.

4.    It is important to monitor serium sodium levels closely for client at risk for hyponatremia, as well as monitoring urinary sodium levels and specific gravity.

5.    The elderly are at increased risk for hyponatremia due to changes in renal function and a relative decreased ability to excrete excessive water loads. Hyponatremia is a frequently overlooked cause of confusion in elderly clients.

Nursing Diagnosis

1.    Altered thought processes related to changes in CNS activity

2.    Pain (headache) related to increased intracranial pressure

Additional Nursing Diagnoses

1.    Fluid volume excess related to excessive water intake

2.    Altered nutrition: less than body requirements related to inadequate sodium intake

3.    Potential for injury related to postural hypotension or skeletal muscle weakness

4.    Total self-care deficit related to muscle weakness

5.    Pain related to abdominal cramping secondary to increased GI peristalsis

6.    Potential impaired skin integrity related to excesses or deficiencies of interstitial fluid

7.    Body image disturbance related to weight gain

8.    Knowledge deficit related to treatment regimen

9.    Impaired physical mobility related to muscle weakness

Nursing Plan and Interventions

The plan of care aims to:

1.    Restore normal sodium and fluid balance

2.    Provide supportive care for altered physiologic function and to prevent associated complications.

3.    Prevent future sodium imbalances.

Goals

1.    The client will have serum sodium levels restored to normal

2.    The client will accurately interpret environmental stimuli

3.    The client will remain in a safe environment 

4.    The client will achieve an acceptable level of headache relief.

Interventions

1.    The focus of nursing interventions is to prevent further decreases in serum sodium levels, increase below-normal serum sodium levels, and to provide a safe environment

2.    The nurse assesses the client’s CNS functional activity at least during every shift to evaluate the effectiveness of current interventions and to determine whether a sodium imbalance continues to exist.

3.    Changes to be assessed include the LOC, orientation, memory the ability to concentrate and cognitive function.

4.    Drug therapy focuses on restoration of normal serum sodium levels.

5.    The therapy is dependent on the cause and can include either the addition or the retention of sodium.

6.    IV saline infusions are useful in restoring both sodium content and fluid volume.The rate of infusion should be regulated by the rate of the sodium or fluid loss. If replaced too rapidly the nurse would expect to fine signs of CNS excitablility.

7.    When hyponatremia is accompanied by fluid excess, drug therapy includes the administration of diuretics that are water excreting rather than sodium secreting.

8.    When cerebral edema is profound, drugs that specifically promote CNS fluid loss may be prescribed. The nurse administers these agents with care and assesses the client every 2 hours for signs that indicate excessive loss of fluids or potassium or for increases in sodium levels.

9.    Drug therapy used for the inappropriate or excessive secretion of ADH may include agents that disturb or prevent ADH. The nurse must be aware of their actions, expected side effects, and potential adverse reactions.

10. When the cause of hyponatremia is due to an underlying pathological change, drug therapy focuses on the treatment of the underlying condition;

11. For mild hyponatremia, diet therapy can be of benefit in restoring normal sodium balance, usually consisting of increasing oral sodium intake and restricting oral intake of fluids.

12. When overhydration with oral hypotonic fluids is the underlying cause of the hyponatremia or when renal fluid excretion is impaired, fluid restriction may be a long-term therapy.

13. The nurse accurately measures fluid intake and output.

14. Dietary changes of sodium have little effect on severe hyponatrimia or hyponatremia due to non-renal chronic pathologic conditions.

15. Changes in CNS functions and responses are expected in the client with hyponatremia. These changes vary from mild anxiety to psychosis and from drowsiness to coma or convulsions.

16. Maintaining a safe environment for the client is an important nursing function.

17. The nurse orients the client to time and place at every interaction and reminds the client of who the nurse is and what the nurse is doing.

18. The nurse reduces excessive environmental stimuli to deep the client from becoming confused. The telephone and television volumes are adjusted to keep a quiet and peaceful environment.

19. The nurse must provide assistance if the client is ambulatory to prevent falls.

20. Side rails should be kept up at all times and the bed kept close to the floor.

21. Intracranial pressure (ICP) can be increased through position changes and other body pressure changes within the client’s voluntary control, such as the valsalva maneuver (holding one’s breath and forcefully contracting specific muscle groups) increases intracranial pressure. This maneuver is uses during defecating, urinating, coughing, nose blowing, lifting, and intercourse.

22. Drug therapy is aimed at decreasing the frequency and intensity of the Valsalva maneuver for these clients. Treatment of the underlying causes for increased use of the Valsalva is administered such as stool softeners, laxatives, and remedies for colds and coughs.

23. Drug therapy is also aimed at helping to reduce the client’s perception of pain by administering analgesic medications.

24. Specific positions and position changes can increase intracranial pressure.

25. Any time the head is on the same level as the heart or is lower that the heart, ICP is increased due to reduced venous return.

26. The nurse explains this phenomenon to the client and cautions the client to avoid activities that involve bending over.

27. The head of the bed is placed at a minimum of a 15-degree angle, and the client is never permitted to be in a flat position.

28. Nursing actions that may help to relieve pain due to headache and increase client comfort include reducing of environmental stimuli, the use of ice packs, and avoidance of activities and procedures that upset the client.

29. Reducing environment stimuli such as noises from telephones, television and visitors are implemented.

30. The nurse examines the client’s medication schedule and activities to determine which ones can be combined to provide the least amount of disturbance and which activities can be avoided if not absolutely necessary.

Evaluation

The nurse evaluates the care for the client on the basis of the identified nursing diagnoses. The expected outcomes for the client include that the client

1.    Restores and maintains normal serum sodium levels

2.    Identifies actions to take when the signs and symptoms of hyponatremia occur

3.    Achieves an acceptable level of comfort related to decreased in headache and abdominal cramping

4.    Maintains or increases the current level of participation in self-care activities

5.    Interprets accurately environmental stimuli, as evidenced by correct orientation to time, place, and person.

6.    Avoids injury

7.    Maintains an adequate intake of foods and fluids

8.    Maintains skin integrity

9.    Verbalizes knowledge of the prescribed medical regimen

10. Complies with the prescribed medical regimen

Sodium Excess (Hypernatremia)

Medical Approach

Etiology

1.    Hypernatremia occurs when the serum sodium level is greater than 145 mEq/L.

2.    Hypernatremia can be caused by either a gain of sodium in excess of water or by a loss of water in excess of sodium.

3.    It can occur in clients with normal fluid volume or in those with FVD or FVE.

Causes

1.    A common cause of hypernatremia in a hospitalized client is deprivation of water in unconscious clients who are unable to verbalize thirst.

2.    Most often affected are the very old and the very young, who unable to verbalize their thirst.

3.    Clients also affected are those receiving hypertonic tube feedings without adequate water supplements.

4.    Other causes are watery diarrhea and greatly increased insensible water loss such as in hyperventilation and effects of severe burns.

5.    Intravenous administration of hypertonic saline or excessive use of sodium bicarbonate will also cause hypernatremia.

Clinical Manifestations of Hypernatremia

1.    The clinical manifestations of hypernatremia are primarily neurologic and are caused by cellular dehydration.

2.    In moderate hypernatremia, the signs and symptoms include restless and weakness.

3.    With severe hypernatremia, disorientation, delusions, and hallucinations are present.

4.    Dehydration, resulting in dehydration, is often overlooked as the primary reason for behavioral changes in the elderly.

5.    If hypernatremia is severe, permanent brain damage can occur, especially in children. Damage to the brain is due to subarachnoid hemorrhages caused by brain contraction.

6.    The primary characteristic of hypernatremia is thirst, although this indicator is diminished in ill persons and absent in the unconscious client.

7.    Other signs include dry, swollen tongue, sticky mucous membranes, flushed skin, elevated temperature, peripheral and pulmonary edema, postural hypotension and increased muscle tone.

8.    Mild hypernatremia may induce erratic muscle twitches and irregular contractions. As the degree of hypernatremia increases, the ability of skeletal muscle cells and nerves to respond to stimulus diminishes. Muscles become progressively weaker and may demonstrate rigid paralysis.

Management of Hypernatremia

1.    Treatment of hypernatremia consists of a gradual lowering of the serum sodium level by the infusion of a hypotonic electrolyte solution (0.3% NaCl) or an isotonic solution (D5W).

2.    A rapid reduction in the serum sodium level decreases the plasma osmolarity below that of the fluid in the brain tissue, causing dangerous cerebral edema.

3.    Diuretics are also used to treat elevated sodium levels.

Nursing Approach

Nursing Assessment

1.    The nurse should assess for abnormal losses of water or low water intake and for large gains of sodium, as from food or some medications that are high in sodium.

2.    Monitoring of the intake and output and the disproportion between them are noted. The urine is usually greatly decreased in amount and concentrated with a dark amber color.

3.    Also assessment of thirst and elevated body temperature is noted.

4.    Clients should be monitored for changes in behavior, such as restlessness, disorientation, and lethargy.

5.    The nurse assesses neuromuscular status by observing for the presence of isolated twitching in muscle groups.

6.    Muscle strength is also measured by having the client squeeze the nurse’s hands, and by pushing his feet against a flat surface.

7.    The nurse assesses the cardiac status by taking the blood pressure and measuring the rate and quality of the apical and peripheral pulses. Pulse rate and BP vary according to ECF volumes.

·        Normal ECF volumes during hypernatremia usually have normal pulse rates and BP that do not significantly change with position variations.

• Decreased ECF volumes during hypernatremia cause increased pulse rates, decreased blood pressure with pronounced postural hypotension, and the pulse pressure is greatly diminished. Also peripheral pulses can be difficult to palpate and are easily obliterated with mild pressure.

• Increased ECF volumes during hypernatremia can cause slow to normal bounding pulses. Peripheral pulses are  full and difficult to obliterate. Neck veins may be distended, even when sitting upright. Blood pressure, especially the diastolic pressure, is increased.

8.    Skin condition changes often are good indicators of what specific type of ECF volume change      accompanies the hypernatremia. The skin is assessed for integrity, moisture, and the presence of edema. The skin may be dry and flaky.

9.    Decreased ECF volumes in hypernatremia leaves the skin firm or rubbery. No depressions remain in the skin after pressure in applied. When the skin over the back of the hand is pinched to indicate skin turgor, it immediately returns to its normal position when released.

10. Excessive ECF volumes in hypernatremia makes the skin color range from pale to flushed. Skin turgor is increased. It may be difficult or impossible to pinch the skin up. Depressions appear in the skin in response to light pressure and remain for many minutes after pressure is removed.

Nursing Diagnosis

1.    Altered nutrition: greater than body requirements related to excessive sodium intake

2.    Altered oral mucous membrane related to inadequate oral secretions

3.    Anxiety related to increased CNS irritability

Additional Nursing Diagnoses

1.    Potential for injury (fall) related to postural hypotension and neuromuscular changes

2.    Decreased cardiac output related to decreased ventricular contractility

3.    Potential impaired skin integrity related to excesses or deficiencies of interstitial fluid

4.    Knowledge deficit related to treatment regimen

5.    Impaired physical mobility related to skeletal muscle weakness

6.    Total self-care deficit related to generalized skeletal muscle weakness

Nursing Plan and Interventions

The nurse must remember that the plan of care is aimed at:

1.    Restoration of normal sodium and fluid balances

2.    Prevention of future sodium imbalances

3.    Providing supportive care for altered body functions

Goals

1.      The client will have serum sodium levels restored to normal

2.      The client will comply with prescribed sodium restrictions

3.      The client will experience less discomfort

4.      Maintain normal oral mucosal integrity

5.      Maintain an adequate nutritional intake

Interventions

1.    The nursing interventions are aimed at preventing further increases in serum sodium levels and decreasing elevated serum sodium level

2.    Drug therapy focuses on restoring fluid balance when hypernatremia is caused by fluid loss by infusing IV solutions of glucose and water (D₅W).

3.    When hypernatremia is caused by fluid and sodium losses, it is necessary to replace the fluid with IV solutions of isotonic NaCl.

4.    When hypernatremia is caused by inadequate renal excretion of sodium, drug therapy includes the use of diuretics which enhance sodium loss.

5.    Dietary restrictions of sodium are very useful in preventing hypernatremia and preventing an existing hypernatremic condition from becoming worse.

6.    Dietary restriction of sodium is ineffective if rapid reduction of excess serum sodium is needed.

7.    The nurse provide frequent oral hygiene to prevent tissue breakdowns and the development of sores

8.    The nurse minimizes the environmental stimuli of the client, providing less stimuli to keep the client in a less excitable state

9.    Muscle relaxants or tranquilizers may be prescribed and the nurse monitors for their effect and their adverse reactions

10. The nurse provides opportunities for the client to ask questions in order to relieve his anxiety

Evaluation

1.      Restores and maintains normal serum sodium level

2.      Identifies actions to take when signs and symptoms occur

3.      Reduction or alleviation of oral mucous membrane discomfort

4.      Maintains adequate oral intake

5.      Describes restrictions enforced in diet

6.      Maintain good skin integrity

7.      Describes regimen of medications and their potential side effects

Potassium Imbalances

Potassium is the major intracellular electrolyte, it contains 98% of the body’s potassium. The remaining 2% is in the ECF. It is this 2% that is important in neuromuscular function (skeletal and cardiac muscle activity). Because the extracellular amount is so small, even the smallest variation of potassium there causes major changes in cell membrane excitability.

Potassium Deficit (Hypokalemia)

Medical Approach

Etiology

  1.  Hypokalemia exists when the serum potassium level falls below 3.5 mEq/L.

  2.  Hypokalemia is a common imbalance.

  3.  Total body potassium is lost as a result of excessive renal excretion of potassium or more commonly, by excessive potassium loss through the gastrointestinal (GI) tract.

Causes

1.    Vomiting and gastric suction usually lead to hypokalemia partly because potassium is actually lost when gastric fluid is lost, but more so because potassium is lost through the kidneys in the associated metabolic alkalosis.

2.    Hypokalemia occurs from diarrhea, prolonged intestinal suctioning, recent ileostomy, and villous adenoma (a tumor of the intestinal tract).

3.    The use of some diuretics or any state in which aldosterone secretion in increased promotes excessive renal excretion of potassium.

4.    Hypokalemia can also occur without actual loss of potassium from the body. This condition is caused when potassium is moved from the ECF to the ICF.

5.    Conditions that tend to cause this intracellular uptake of potassium include metabolic alkalosis and the presence of excess amounts of insulin in the blood, such as during hyperalimentation infusions or during treatment of uncontrolled diabetes.

6.    Individuals who take nothing by mouth for several days are at risk for hypokalemia. These clients would include debilitated elderly people, alcoholics, and those clients with anorexia. Clients with bulimia frequently suffer with hypokalemia due to the self-induced vomiting and abuse of laxatives and diuretics.

Clinical Manifestations of Hypokalemia

1.    Clinical signs rarely develop until the serum potassium level falls below 3mEq/L.

2.  &