1. Fluid and Electrolytes: Balance and Disturbance Dr. Abdul-Monim Batiha

2. Fluid and Electrolyte Balance
Necessary for life, homeostasis
Nursing role: help prevent, treat fluid, electrolyte disturbances

3. Fluid Approximately 60% of typical adult is fluid
Varies with age, body size, gender
Intracellular fluid
Extracellular fluid
Intravascular: the fluid within the blood vessels e.g. plazma
Interstitial: fluid surrounds the cell (e.g. lymph
Transcellular: cerebrospinal, pericardial, synovial, intraocular, pleural, sweat and digestive secretion
“Third spacing”: loss of ECF into space that does not contribute to equilibrium

6. Electrolytes
Active chemicals that carry positive (cations), negative (anions) electrical charges
Major cations: sodium, potassium, calcium, magnesium, hydrogen ions
Major anions: chloride, bicarbonate, phosphate, sulfate, and proteinate ions
Electrolyte concentrations differ in fluid compartments

7. Regulation of Fluid
Movement of fluid through capillary walls depends on
Hydrostatic pressure: exerted on walls of blood vessels
Osmotic pressure: exerted by protein in plasma
Direction of fluid movement depends on differences of hydrostatic, osmotic pressure

8. Regulation of Fluid
Osmosis: area of low solute concentration to area of high solute concentration
Diffusion: solutes move from area of higher concentration to one of lower concentration
Filtration: movement of water, solutes occurs from area of high hydrostatic pressure to area of low hydrostatic pressure
Active transport: physiologic pump that moves fluid from area of lower concentration of one of higher concentration

11. Active Transport
Physiologic pump that moves fluid from area of lower concentration to one of higher concentration
Movement against concentration gradient
Sodium-potassium pump: maintains higher concentration of extracellular sodium, intracellular potassium
Requires adenosine (ATP) for energy

13. Question Tell whether the following statement is true or false:
Osmosis is the movement of a substance from an area of higher concentration to one of lower concentration.

14. Answer
False.
Rationale: Diffusion is the movement of a substance from an area of higher concentration to one of lower concentration. The concentration of dissolved substances draws fluid in that direction. Osmosis is the movement of fluid, through a semipermeable membrane, from an area of low solute concentration to an area of high solute concentration until the solutions are of equal concentration.

15. Routes of Gains and Losses
Dietary intake of fluid, food or enteral feedingIngested fluid (60%) and solid food (30%)
Metabolic water or water of oxidation (10%)
Parenteral fluids

16. Routes of Gains and Losses (cont’d)
Kidney: urine output
Skin loss: sensible, insensible losses
Lungs
GI tract
Other
Urine (60%) and feces (4%)
Insensible losses (28%), sweat (8%)

17. Water Intake and Output
Figure 26.4
Chapter 26: Fluid, Electrolyte, and Acid-Base Balance

18. Question What is the average daily urinary output in an adult? 0.5 L

19. Answer
C. 1.5 L
Rationale: Vital to the regulation of fluid and electrolyte balance, the kidneys normal filter 170 L of plasma every day in the adult, while excreting only 1.5 L of urine.

20. Regulation of Water Intake
The hypothalamic thirst center is stimulated:
By a decline in plasma volume of 10%–15%
By increases in plasma osmolality of 1–2%
Via baroreceptor input, angiotensin II, and other stimuli

21. Thirst is reduced as soon as we begin to drink water
Feedback signals that inhibit the thirst centers include:
Moistening of the mucosa of the mouth and throat
Activation of stomach and intestinal stretch receptors

22. Regulation of Water Output
Obligatory water losses include:
Insensible water losses from lungs and skin
Water that accompanies undigested food residues in feces
Obligatory water loss reflects the fact that:
Kidneys excrete mOsm of solutes to maintain blood homeostasis
Urine solutes must be flushed out of the body in water

23. Influence and Regulation of ADH
Water reabsorption in collecting ducts is proportional to ADH release
Low ADH levels produce dilute urine and reduced volume of body fluids
High ADH levels produce concentrated urine
Hypothalamic osmoreceptors trigger or inhibit ADH release
Factors that specifically trigger ADH release include prolonged fever; excessive sweating, vomiting, or diarrhea; severe blood loss; and traumatic burns

24. Mechanisms and Consequences of ADH Release
Figure 26.6

26. Fluid Volume Imbalances
Fluid volume deficit (FVD): hypovolemia
Fluid volume excess (FVE): hypervolemia

27. Fluid Volume Deficit
Loss of extracellular fluid exceeds intake ratio of water
Electrolytes lost in same proportion as they exist in normal body fluids
Dehydration: loss of water along with increased serum sodium level
May occur in combination with other imbalances

28. Fluid Volume Deficit (cont’d)
Dehydration
Causes: fluid loss from vomiting, diarrhea, GI suctioning, sweating, decreased intake, inability to gain access to fluid
Risk factors: diabetes insipidus, adrenal insufficiency, osmotic diuresis, hemorrhage, coma,

29. Fluid Volume Deficit (cont’d)
Manifestations: rapid weight loss, decreased skin turgor, oliguria, concentrated urine, postural hypotension, rapid weak pulse, increased temperature, cool clammy skin due to vasoconstriction, lethargy, thirst, nausea, muscle weakness, cramps
Laboratory data: elevated BUN in relation to serum creatinine, increased hematocrit
Serum electrolyte changes may occur

30. Fluid Volume Deficit (cont’d)
Medical management: provide fluids to meet body needs
Oral fluids
IV solutions (isotonic electrolytes solution; e.g. ringer lactate solution or 0.9 sodium chloride)

31. Fluid Volume Deficit - Nursing Management
I&O, VS
Monitor for symptoms: skin and tongue turgor, mucosa, UO, mental status
Measures to minimize fluid loss
Oral care
Administration of oral fluids
Administration of parenteral fluids

32. Question What is a major indicator of extracellular FVD?
Full and bounding pulse
Drop in postural blood pressure
Elevated temperature
Pitting edema of lower extremities

33. Answer B. Drop in postural blood pressure
Rationale: FVD signs and symptoms include acute weight loss; decreased skin turgor; oliguria; concentrated urine; orthostatic hypotension due to volume depletion; a weak, rapid heart rate; flattened neck veins; increased temperature; thirst; decreased or delayed capillary refill; decreased central venous pressure; cool, clammy, pale skin related to peripheral vasoconstriction; anorexia; nausea; lassitude; muscle weakness; and cramps. Clinical manifestations of FVE result from expansion of the ECF and include edema, distended neck veins, and crackles (abnormal lung sounds).

34. Fluid Volume Excess
Due to fluid overload or diminished homeostatic mechanisms
Risk factors: heart failure, renal failure, cirrhosis of liver
Contributing factors: excessive dietary sodium or sodium-containing IV solutions
Manifestations: edema, distended neck veins, abnormal lung sounds (crackles), tachycardia, increased BP, pulse pressure and CVP, increased weight, increased UO, shortness of breath and wheezing
Medical management: directed at cause, restriction of fluids and sodium, administration of diuretics

36. Disorders of Water Balance: Edema
Atypical accumulation of fluid in the interstitial space, leading to tissue swelling
Caused by anything that increases flow of fluids out of the bloodstream or hinders their return
Factors that accelerate fluid loss include:
Increased blood pressure, capillary permeability
Incompetent venous valves, localized blood vessel blockage
Congestive heart failure, hypertension, high blood volume

37. Edema
Hindered fluid return usually reflects an imbalance in colloid osmotic pressures
Hypoproteinemia – low levels of plasma proteins
Forces fluids out of capillary beds at the arterial ends
Fluids fail to return at the venous ends
Results from protein malnutrition, liver disease, or glomerulonephritis

38. Edema Chapter 26: Fluid, Electrolyte, and Acid-Base Balance
Blocked (or surgically removed) lymph vessels:
Cause leaked proteins to accumulate in interstitial fluid
Exert increasing colloid osmotic pressure, which draws fluid from the blood
Interstitial fluid accumulation results in low blood pressure and severely impaired circulation
Chapter 26: Fluid, Electrolyte, and Acid-Base Balance

39. Fluid Volume Excess - Nursing Management
I&O and daily weights; assess lung sounds, edema, other symptoms; monitor responses to medications- diuretics
Promote adherence to fluid restrictions, patient teaching related to sodium and fluid restrictions
Monitor, avoid sources of excessive sodium, including medications
Promote rest
Semi-Fowler’s position for orthopnea
Skin care, positioning/turning

40. Electrolyte Imbalances
Sodium: hyponatremia, hypernatremia
Potassium: hypokalemia, hyperkalemia
Calcium: hypocalcemia, hypercalcemia
Magnesium: hypomagnesemia, hypermagnesemia
Phosphorus: hypophosphatemia, hyperphosphatemia
Chloride: hypochloremia, hyperchloremia

41. Hyponatremia Serum sodium less than 135 mEq/L
Causes: adrenal insufficiency, water intoxication, SIADH (Syndrome of inappropriate ADH secretion) or losses by vomiting, diarrhea, sweating, diuretics
Manifestations: poor skin turgor, dry mucosa, headache, decreased salivation, decreased BP, nausea, abdominal cramping, neurologic changes
Medical management: water restriction, sodium replacement
Nursing management: assessment and prevention, dietary sodium and fluid intake, identify and monitor at- risk patients, effects of medications (diuretics, lithium)

42. Hypernatremia Serum sodium greater than 145mEq/L
Causes: excess water loss, excess sodium administration, diabetes insipidus, heat stroke, hypertonic IV solutions
Manifestations: thirst; elevated temperature; dry, swollen tongue; sticky mucosa; neurologic symptoms; restlessness; weakness
Note: thirst may be impaired in elderly or the ill
Medical management: hypotonic electrolyte solution or D5W
Nursing management: assessment and prevention, assess for OTC (Over the counter drugs) sources of sodium, offer and encourage fluids to meet patient needs, provide sufficient water with tube feedings

44. Hypokalemia
Below-normal serum potassium (<3.5 mEq/L), may occur with normal potassium levels with alkalosis due to shift of serum potassium into cells
Causes: GI losses, medications, alterations of acid-base balance, hyperaldosterism, poor dietary intake
Manifestations: fatigue, anorexia, nausea, vomiting, dysrhythmias, muscle weakness and cramps, paresthesias, glucose intolerance, decreased muscle strength and DTRs
Medical management: increased dietary potassium, potassium replacement, IV for severe deficit
Nursing management: assessment, severe hypokalemia is life-threatening, monitor ECG and ABGs, dietary potassium, nursing care related to IV potassium administration

45. Hyperkalemia Serum potassium greater than 5.0 mEq/L
Causes: usually treatment related, impaired renal function, hypoaldosteronism, tissue trauma, acidosis
Manifestations: cardiac changes and dysrhythmias, muscle weakness with potential respiratory impairment, paresthesias, anxiety, GI manifestations
Medical management: monitor ECG, limitation of dietary potassium, cation-exchange resin (Kayexalate), IV sodium bicarbonate , IV calcium gluconate, regular insulin and hypertonic dextrose IV, -2 agonists, dialysis

46. Hyperkalemia (cont’d)
Nursing management: assessment of serum potassium levels, mix IVs containing K+ well, monitor medication affects, dietary potassium restriction/dietary teaching for patients at risk
Hemolysis of blood specimen or drawing of blood above IV site may result in false laboratory result
Salt substitutes, medications may contain potassium
Potassium-sparing diuretics may cause elevation of potassium
Should not be used in patients with renal dysfunction

47. Question Tell whether the following statement is true or false:
The ECG change that is specific to hyperkalemia is a peaked T wave.

48. Answer
True.
Rationale: The ECG changes that are specific to hyperkalemia are peaked T wave; wide, flat P wave; and wide QRS complex. The ECG changes that are specific to hypokalemia are flatted T wave and the appearance of a U wave.

49. Hypocalcemia
Serum level less than 8.5 mg/dL, must be considered in conjunction with serum albumin level
Causes: hypoparathyroidism, malabsorption, pancreatitis, alkalosis, massive transfusion of citrated blood, renal failure, medications, other
Manifestations: tetany, circumoral numbness, paresthesias, hyperactive DTRs, Trousseau’s sign, Chovstek's sign, seizures, respiratory symptoms of dyspnea and laryngospasm, abnormal clotting, anxiety

50. Hypocalcemia (cont’d)
Medical management: IV of calcium gluconate, calcium and vitamin D supplements; diet
Nursing management: assessment, severe hypocalcemia is life-threatening, weight-bearing exercises to decrease bone calcium loss, patient teaching related to diet and medications, and nursing care related to IV calcium administration

51. Trousseau’s Sign

52. Hypercalcemia 9-11 Serum level above 11 mg/dL
Causes: malignancy and hyperparathyroidism, bone loss related to immobility
Manifestations: muscle weakness, incoordination, anorexia, constipation, nausea and vomiting, abdominal and bone pain, polyuria, thirst, ECG changes, dysrhythmias
Medical management: treat underlying cause, fluids, furosemide, phosphates, calcitonin, biphosphonates
Nursing management: assessment, hypercalcemic crisis has high mortality, encourage ambulation, fluids of 3 to 4 L/d, provide fluids containing sodium unless contraindicated, fiber for constipation, ensure safety

53. Hypomagnesemia ( normal 1.8-3)
Serum level less than 1.8 mg/dL, evaluate in conjunction with serum albumin
Causes: alcoholism, GI losses, enteral or parenteral feeding deficient in magnesium, medications, rapid administration of citrated blood; contributing causes include diabetic ketoacidosis, sepsis, burns, hypothermia
Manifestations: neuromuscular irritability, muscle weakness, tremors, ECG changes and dysrhythmias, alterations in mood and level of consciousness
Medical management: diet, oral magnesium, magnesium sulfate IV

54. Hypomagnesemia (cont’d)
Nursing management: assessment, ensure safety, patient teaching related to diet, medications, alcohol use, and nursing care related to IV magnesium sulfate
Hypomagnesemia often accompanied by hypocalcemia
Need to monitor, treat potential hypocalcemia
Dysphasia common in magnesium-depleted patients
Assess ability to swallow with water before administering food or medications

55. Hypermagnesemia Serum level more than 2.7 mg/dL
Causes: renal failure, diabetic ketoacidosis, excessive administration of magnesium
Manifestations: flushing, lowered BP, nausea, vomiting, hypoactive reflexes, drowsiness, muscle weakness, depressed respirations, ECG changes, dysrhythmias
Medical management: IV calcium gluconate, loop diuretics, IV NS of RL, hemodialysis
Nursing management: assessment, do not administer medications containing magnesium, patient teaching regarding magnesium containing Over-the-counter drug.

56. Hypophosphatemia (normal 3-4.5)
Serum level below 2.5 mg/DL
Causes: alcoholism, refeeding of patients after starvation, pain, heat stroke, respiratory alkalosis, hyperventilation, diabetic ketoacidosis, hepatic encephalopathy, major burns, hyperparathyroidism, low magnesium, low potassium, diarrhea, vitamin D deficiency, use of diuretic and antacids
Manifestations: neurologic symptoms, confusion, muscle weakness, tissue hypoxia, muscle and bone pain, increased susceptibility to infection
Medical management: oral or IV phosphorus replacement
Nursing management: assessment, encourage foods high in phosphorus, gradually introduce calories for malnourished patients receiving parenteral nutrition

57. Hyperphosphatemia Serum level above 4.5 mg/DL
Causes: renal failure, excess phosphorus, excess vitamin D, acidosis, hypoparathyroidism, chemotherapy
Manifestations: few symptoms; soft-tissue calcifications, symptoms occur due to associated hypocalcemia
Medical management: treat underlying disorder, vitamin- D preparations, calcium-binding antacids, phosphate- binding gels or antacids, loop diuretics, NS IV, dialysis
Nursing management: assessment, avoid high- phosphorus foods; patient teaching related to diet, phosphate-containing substances, signs of hypocalcemia

58. Hypochloremia Serum level less than 96 mEq/L
Causes: Addison’s disease, reduced chloride intake, GI loss, diabetic ketoacidosis, excessive sweating, fever, burns, medications, metabolic alkalosis
Loss of chloride occurs with loss of other electrolytes, potassium, sodium
Manifestations: agitation, irritability, weakness, hyperexcitability of muscles, dysrhythmias, seizures, coma
Medical management: replace chloride-IV NS or 0.45% NS
Nursing management: assessment, avoid free water, encourage high-chloride foods, patient teaching related to high-chloride foods

59. Hyperchloremia (96-109) Serum level more than 108 mEq/L
Causes: excess sodium chloride infusions with water loss, head injury, hypernatremia, dehydration, severe diarrhea, respiratory alkalosis, metabolic acidosis, hyperparathyroidism, medications
Manifestations: tachypnea, lethargy, weakness, rapid, deep respirations, hypertension, cognitive changes
Normal serum anion gap
Medical management: restore electrolyte and fluid balance, LR, sodium bicarbonate, diuretics
Nursing management: assessment, patient teaching related to diet and hydration

60. Maintaining Acid-Base Balance
Normal plasma pH : hydrogen ion concentration
Major extracellular fluid buffer system; bicarbonate-carbonic acid buffer system
Kidneys regulate bicarbonate in ECF
Lungs under control of medulla regulate CO2, carbonic acid in ECF

61. Maintaining Acid-Base Balance (cont’d)
Other buffer systems
ECF: inorganic phosphates, plasma proteins
ICF: proteins, organic, inorganic phosphates
Hemoglobin

62. Question What is the most common buffer system in the body?
Plasma protein
Hemoglobin
Phosphate
Bicarbonate-carbonic acid

63. Answer D. Bicarbonate-carbonic acid
Rationale: The body’s major extracellular buffer system is the bicarbonate–carbonic acid buffer system, which is assessed when arterial blood gases are measured.

64. Metabolic Acidosis Low pH <7.35 Low bicarbonate <22 mEq/L
Most commonly due to renal failure
Manifestations: headache, confusion, drowsiness, increased respiratory rate and depth, decreased blood pressure, decreased cardiac output, dysrhythmias, shock; if decrease is slow, patient may be asymptomatic until bicarbonate is 15 mEq/L or less
Correct underlying problem, correct imbalance
Bicarbonate may be administered

65. Metabolic Acidosis (cont’d)
With acidosis, hyperkalemia may occur as potassium shifts out of cell
As acidosis is corrected, potassium shifts back into cell, potassium levels decrease
Monitor potassium levels
Serum calcium levels may be low with chronic metabolic acidosis
Must be corrected before treating acidosis

66. Metabolic Alkalosis High pH >7.45 High bicarbonate >26 mEq/L
Most commonly due to vomiting or gastric suction
May also be due to medications, especially long-term diuretic use
Hypokalemia will produce alkalosis
Manifestations: symptoms related to decreased calcium, respiratory depression, tachycardia, symptoms of hypokalemia

67. Metabolic Alkalosis (cont’d)
Correct underlying disorder, supply chloride to allow excretion of excess bicarbonate, restore fluid volume with sodium chloride solutions

68. Respiratory Acidosis Low pH <7.35 PaCO2 >42 mm Hg
Always due to respiratory problem with inadequate excretion of CO2
With chronic respiratory acidosis, body may compensate, may be asymptomatic
Symptoms may be suddenly increased pulse, respiratory rate and BP, mental changes, feeling of fullness in head

69. Respiratory Acidosis (cont’d)
Potential increased intracranial pressure
Treatment aimed at improving ventilation

70. Respiratory Alkalosis
High pH >7.45
PaCO2 <35 mm Hg
Always due to hyperventilation
Manifestations: lightheadedness, inability to concentrate, numbness and tingling, sometimes loss of consciousness
Correct cause of hyperventilation

71. Arterial Blood Gases pH 7.35 - (7.4) - 7.45 PaCO2 35 - (40) - 45 mm Hg
HCO3ˉ 22 - (24) - 26 mEq/L
Assumed average values for ABG interpretation
PaO2 80 to 100 mm Hg
Oxygen saturation >94%
Base excess/deficit ±2 mEq/L

72. Parenteral fluid therapy
Purpose:
1- to provide water, electrolytes, and nutrition to meet daily requirements.
2- to replace water and correct electrolytes imbalance
3- to administer medication and blood products

73. Types
Isotonic fluids: which have a total osmolality close to that of the ECF and does not effect on RBC. 1 lit of these solutions expand the ECF by 1 lit and the plasma by lit
1- D5W: used for supply water and increase serum osmolality; don't administer it during fluid resuscitation bcz of hyperglycemia
About 1lit of D5W provides fewer than 200 kcal
2- normal saline: (0.9%): used to correct the EC volume defect, within blood administration, to replace sodium losses in case of burn.
- Not used for HF, PE, Renal impairment, sodium retention

74. Types (cont…)
3- other solutions: Lactated Ringers; contains potassium, calcium, and sodium chloride.
Used to correct dehydration, sodium depletion, and replace GI losses
Hypotonic fluids: used to replace cellular fluid, provide free water to excrete the body wastes, treat hypernatremia and other hyperosmolar conditions.
1- half strength saline (0.45% sodium chloride)
SE of the excessive use of hypotonic solutions leads to intravascular fluids depletion, decrease BP, cellular edema, and cell damage

75. Hypertonic fluids: when normal saline and Lactated ringer’s contains 5% dextrose, the total osmolality exceed that the ECF
Other IV substances:
When the patient is unable to tolerate food, nutritional requirements are often met using IV route
- e.g. 50% dextrose in water. Protein, or fat,

76. hypertonic
A solution that exerts a higher osmotic pressure than that of blood plasma. Administration of this fluid increases the solute concentration of plasma, drawing water out of the cells and into the extracellular compartment to restore osmotic equilibrium; cells will then shrink.
1. D5W in normal saline solution.
2. D5W in half normal saline solution (only slightly hypertonic
because dextrose is rapidly metabolized and renders only temporary osmotic pressure).

77. 3. Dextrose 10% in water.
4. Dextrose 20% in water.
5. 3% or 5% sodium chloride solution.
6. Hyperalimentation solutions.
7. D5W in lactated Ringer’s solution.
8. Albumin 25%.

78. IV Site Selection

79. Complications of IV Therapy
Fluid overload, Air embolism
Septicemia, other infections
Infiltration: is the unintentional administration of nonvesicant solutions or medication into surrounding tissue as a result of dislodges or perforates the wall of the veins ,

80. extravasation: similar to Infiltration with an inadvertent administration of vesicant or irritant solution
Phlebitis
Thrombophlebitis
Hematoma
Clotting, obstruction

81. Composition of Fluids
1. Saline solutions—water and electrolytes (Na+, Cl−).
2. Dextrose solutions—water or saline and calories.
3. Lactated Ringer’s solution—water and electrolytes (Na+, K+,Cl−, Ca++, lactate).
4. Balanced isotonic solution—varies; water, some calories, electrolytes(Na+, K+, Mg++, Cl−, HCO3−, gluconate).

82. 5. Whole blood and blood components.
6. Plasma expanders—albumin, mannitol, dextran, plasma protein fraction 5%, hetastarch; exert increased oncotic pressure, pulling fluid from interstitium into the circulation and temporarily increasing blood volume.
7. Parenteral hyperalimentation—fluid, electrolytes, amino acids, and calories.

83. Uses and Precautions with Common Types of Infusions
1. D5W
a. Used to replace water (hypotonic fluid) losses, supply
some caloric intake, or administer as carrying solution for numerous medications.
b. Should be used cautiously in patients with water intoxication (hyponatremia, syndrome of inappropriate antidiuretic hormone release). Should not be used as concurrent solution infusion with blood or blood components.

84. 2. Normal saline solution
a. Used to replace saline (isotonic fluid) losses, administer with blood components, or treat patients in hemodynamic shock.
b. Should be used cautiously in patients with isotonic volume excess (heart failure, renal failure).
3. Lactated Ringer’s solution
a. Used to replace isotonic fluid losses, replenish specific
electrolyte losses, and moderate metabolic acidosis. Use
cautiously in patients with liver failure.