1. Fluids and Electrolytes
Chapter 29
Fluids and Electrolytes
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2. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Fluid Balance
Total body water
Composed of:
Intracellular fluid (ICF)
Interstitial fluid (ISF)
Plasma volume (PV)
60% of adult human body is water
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3. Fluid Balance (cont’d)
Intravascular fluid (IVF)
Fluid inside blood vessels
Extravascular fluid (EVF)
Fluid outside blood vessels
Lymph, cerebrospinal fluid
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4. Fluid Balance (cont’d)
Extravascular volume
Plasma
Interstitial fluid (ISF): fluid in space between cells, tissues, and organs
Extracellular volume
ISF (interstitial fluid)
ICF (intracellular fluid)
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5. Distribution of Total Body Water
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6. Fluid Balance (cont’d)
Plasma proteins exert constant osmotic pressure
Colloid oncotic pressure (COP)
Normally 24 mm Hg
ISF exerts hydrostatic pressure (HP)
Normally 17 mm Hg
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7. Colloid Osmotic Pressure
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8. Fluid Balance (cont’d)
Edema
Dehydration and fluid loss
Acid-base balance
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9. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Crystalloids
Solutions containing fluids and electrolytes that are normally found in the body
Do not contain proteins (colloids)
No risk for viral transmission, anaphylaxis, or alteration in coagulation profile
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10. Crystalloids (cont’d)
Better for treating dehydration rather than expanding plasma volume
Used as maintenance fluids to:
Compensate for insensible fluid losses
Replace fluids
Manage specific fluid and electrolyte disturbances
Promote urinary flow
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11. Crystalloids (cont’d)
Normal saline (0.9% sodium chloride)
Half normal saline (0.45% sodium chloride)
Hypertonic saline (3% sodium chloride)
Lactated Ringer’s
D5W
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12. Crystalloids (cont’d)
Indications include:
Acute liver failure
Acute nephrosis
Adult respiratory distress syndrome
Burns
Cardiopulmonary bypass
Hypoproteinemia
Renal dialysis
Reduction of the risk for DVT
Shock
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13. Crystalloids (cont’d)
Adverse effects
May cause edema, especially peripheral or pulmonary
May dilute plasma proteins, reducing COP
Effects may be short-lived
Prolonged infusions may worsen alkalosis or acidosis
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Colloids
Protein substances
Increase COP
Move fluid from interstitial compartment to plasma compartment (when plasma protein levels are low)
Albumin 5% and 25% (from human donors)
Dextran 40, 70, or 75 (a glucose solution)
Hetastarch (synthetic, derived from cornstarch)
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15. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Colloids (cont’d)
Adverse effects
Usually safe
May cause altered coagulation, resulting in bleeding
Have no clotting factors or oxygen-carrying capacity
Rarely, dextran therapy causes anaphylaxis or renal failure
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16. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Blood Products
Only class of fluids that are able to carry oxygen
Increase tissue oxygenation
Increase plasma volume
Most expensive and least available fluid because they require human donors
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17. Blood Products (cont’d)
Increase COP and PV
Pull fluid from extravascular space into intravascular space (plasma expanders)
RBC products also carry oxygen
Increase body’s supply of various products (such as clotting factors, hemoglobin)
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18. Blood Products (cont’d)
Indications
Cryoprecipitate and plasma protein factors (PPF)
Management of acute bleeding (greater than 50% slow blood loss or 20% acutely)
Fresh frozen plasma (FFP)
Increase clotting factor levels in patients with demonstrated deficiency
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19. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Blood Products
Indications (cont’d)
Packed red blood cells (PRBCs)
To increase oxygen-carrying capacity in patients with anemia, in patients with substantial hemoglobin deficits, and in patients who have lost up to 25% of their total blood volume
Whole blood
Same as for PRBCs, except that whole blood is more beneficial in cases of extreme (greater than 25%) loss of blood volume because whole blood also contains plasma
Contains plasma proteins, which help draw fluid back into blood vessels from surrounding tissues
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20. Classroom Response Question
A patient is taken to the trauma unit after a motorcycle accident. It is estimated that he has lost 30% of his blood volume and he is in hypovolemic shock. The nurse anticipates a transfusion with which blood product?
Packed red blood cells
Whole blood
Cryoprecipitate
Fresh frozen plasma
Correct answer: B
Rationale: Whole blood is more beneficial in cases of extreme loss of blood volume (over 25%).
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21. Blood Products (cont’d)
Adverse effects
Incompatibility with recipient’s immune system
Crossmatch testing
Transfusion reaction
Anaphylaxis
Transmission of pathogens to recipient (hepatitis, HIV)
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22. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Electrolytes
Principal ECF electrolytes
Sodium cations (Na+)
Chloride anions (Cl−)
Principal ICF electrolyte
Potassium (K+)
Others
Calcium, magnesium, phosphorus
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23. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Potassium
Most abundant positively charged electrolyte inside cells
95% of body’s potassium is intracellular
Potassium content outside of cells ranges from 3.5 to 5 mEq/L
Potassium levels are critical to normal body function
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24. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Potassium (cont’d)
Potassium obtained from foods
Fruit and fruit juices (bananas, oranges, apricots, dates, raisins, broccoli, green beans, potatoes, tomatoes), meats, fish, wheat bread, and legumes
Excess dietary potassium excreted via kidneys
Impaired kidney function leads to higher serum levels, possibly toxicity
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25. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Potassium (cont’d)
Hyperkalemia: excessive serum potassium; serum potassium level over 5.5 mEq/L
Potassium supplements
ACE inhibitors
Renal failure
Excessive loss from cells
Potassium-sparing diuretics
Burns
Trauma
Metabolic acidosis
Infections
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26. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Potassium (cont’d)
Hypokalemia: deficiency of potassium; serum potassium level less than 3.5 mEq/L
Excessive potassium loss (rather than poor dietary intake)
Alkalosis
Corticosteroids
Diarrhea
Ketoacidosis
Laxative misuse
Hyperaldosteronism
Increased secretion of mineralocorticoids
Burns
Thiazide, thiazide-like, and loop diuretics
Vomiting
Malabsorption
Others
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27. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Potassium (cont’d)
Hypokalemia, in the presence of digoxin therapy, can cause digoxin toxicity, resulting in serious ventricular dysrhythmias
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28. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Potassium (cont’d)
Potassium is responsible for:
Muscle contraction
Transmission of nerve impulses
Regulation of heartbeat
Maintenance of acid-base balance
Isotonicity
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29. Classroom Response Question
Which condition does the nurse identify as a late manifestation of hypokalemia?
Muscle weakness
Hypotension
Palpitations
Lethargy
Correct answer: C
Rationale: Palpitations are a late manifestation of hypokalemia. Early manifestations of hypokalemia include muscle weakness, lethargy, and hypotension.
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30. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Potassium (cont’d)
Main indication
Treatment or prevention of potassium depletion when dietary means are inadequate
Other therapeutic uses
Stop irregular heartbeats
Management of tachydysrhythmias that can occur after cardiac surgery
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31. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Potassium (cont’d)
Adverse effects
Oral preparations
Diarrhea, nausea, vomiting, GI bleeding, ulceration
IV administration
Pain at injection site
Phlebitis
Excessive administration
Hyperkalemia
Toxic effects
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32. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Potassium (cont’d)
Hyperkalemia manifestations
Muscle weakness, paresthesia, paralysis, cardiac rhythm irregularities (leading to possible ventricular fibrillation and cardiac arrest)
Treatment of severe hyperkalemia
IV sodium bicarbonate, calcium gluconate or calcium chloride, dextrose with insulin
Sodium polystyrene sulfonate (Kayexalate) or hemodialysis to remove excess potassium
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33. Classroom Response Question
A patient is hypokalemic and will be receiving intravenous potassium. The patient is not on a heart monitor. How should the nurse administer the potassium replacement?
IV push
No more than 10 mEq/hr
No more than 20 mEq/hr
40 mEq/hr
Correct answer: B
Rationale: If IV potassium is administered too rapidly, cardiac arrest may occur. IV potassium should be given no faster than 10 mEq/hr to patients who are not on cardiac monitors. For critically ill patients on cardiac monitors, rates of 20 mEq/hr or more may be used.
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34. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Sodium
Most abundant positively charged electrolyte outside cells
Normal concentration outside cells is 135 to 145 mEq/L
Maintained through dietary intake of sodium chloride
Salt, fish, meats, foods flavored or preserved with salt
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35. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Sodium (cont’d)
Hyponatremia: sodium loss or deficiency; serum levels below 135 mEq/L
Symptoms
Lethargy, stomach cramps, hypotension, vomiting, diarrhea, seizures
Causes
Same causes as hypokalemia; also excessive perspiration (during hot weather or physical work), prolonged diarrhea or vomiting, or renal disorders
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36. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Sodium (cont’d)
Hypernatremia: sodium excess; serum levels over 145 mEq/L
Symptoms
Water retention (edema), hypertension
Red, flushed skin; dry, sticky mucous membranes; increased thirst; elevated temperature; decreased urine output
Causes
Poor renal excretion stemming from kidney malfunction; inadequate water consumption and dehydration
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37. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Sodium (cont’d)
Sodium is responsible for:
Control of water distribution
Fluid and electrolyte balance
Osmotic pressure of body fluids
Participation in acid-base balance
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38. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Sodium (cont’d)
Main indication
Treatment or prevention of sodium depletion when dietary measures are inadequate
Mild
Treated with oral sodium chloride and/or fluid restriction
Severe
Treated with intravenous normal saline or lactated Ringer’s solution
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39. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Sodium (cont’d)
Adverse effects
Oral administration
Nausea, vomiting, cramps
IV administration
Venous phlebitis
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40. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Nursing Implications
Assess baseline fluid volume and electrolyte status
Assess baseline vital signs
Assess skin, mucous membranes, daily weights, I&O
Before giving potassium, assess ECG
Assess for contraindications to therapy
Assess transfusion history
Establish venous access as needed
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41. Nursing Implications (cont’d)
Monitor serum electrolyte levels during therapy
Monitor infusion rate, appearance of fluid or solution, infusion site
Observe for infiltration, other complications of IV therapy
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42. Nursing Implications (cont’d)
Parenteral infusions of potassium must be monitored closely
IV potassium must not be given at a rate faster than 10 mEq/hr to patients who are not on cardiac monitors. For critically ill patients on cardiac monitors, rates of 20 mEq/hr or more may be used.
NEVER give as an IV bolus or undiluted
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43. Nursing Implications (cont’d)
Oral forms of potassium
Must be diluted in water or fruit juice to minimize GI distress or irritation
Monitor for complaints of nausea, vomiting, GI pain, or GI bleeding
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44. Classroom Response Question
A patient with a serum potassium of 6.0 mEq/L is ordered polystyrene sulfonate (Kayexalate) via the NG. When administering the medication the nurse should
administer the drug with sorbitol.
administer the drug with water.
administer the drug with an antacid.
administer the drug with a laxative.
Correct answer: B
Rationale: Polystyrene should be administered with water based on the dose. The nurse should administer each dose as a suspension in a small quantity of water for improved palatability. Follow directions regarding the amount of water to use; it generally ranges from 20 to 100 mL, depending on the dose. The drug should not be administered with sorbitol, antacids, or laxatives.
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Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.

45. Nursing Implications (cont’d)
Administer colloids slowly
Monitor for fluid overload and possible heart failure
For blood products, follow administration procedures closely
Monitor closely for signs of transfusion reactions
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46. Classroom Response Question
Which solution should the nurse administer with packed red blood cells?
Lactated Ringer’s
0.9% sodium chloride
D5W
0.45% sodium chloride
Correct answer: B
Rationale: Blood products must be given only with normal saline (0.9% sodium chloride), because the solution of D5W results in hemolysis of red blood cells.
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Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.

47. Nursing Implications (cont’d)
Monitor for therapeutic response
Normal lab values
RBCs, WBC, H&H, electrolyte levels
Improved fluid volume status
Increased tolerance to activities
Monitor for adverse effects
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