Chapter 05: Fluids and Electrolytes, Acids and Bases

Chapter 05: Fluids and Electrolytes, Acids and Bases

MULTIPLE CHOICE

1.   A nurse is reviewing lab reports. The nurse recalls blood plasma is located in which of the following fluid compartments?

a.   Intracellular fluid (ICF)

b.   Extracellular fluid (ECF)

c.   Interstitial fluid

d.   Intravascular fluid

ANS: D

Blood plasma is the intravascular fluid. ICF is fluid in the cells. ECF is all the fluid outside the cells. Interstitial fluid is fluid between the cells and outside the blood vessels.

REF:   p. 114

2.   A 35-year-old male weighs 70 kg. Approximately how much of this weight is considered the total volume of body water?

a.   5 L b.   10 L c.   28 L d.   42 L

ANS: D

The total volume of body waNteUr fRoSr aI7N0G-kTgBpe.rsCoOn Mis about 42 L or two thirds of 70 kg.

REF:   p. 114

3.   While planning care for elderly individuals, the nurse remembers the elderly are at a higher risk for developing dehydration because they have:

a.   a higher total body water volume.

b.   decreased muscle mass.

c.   increased thirst.

d.   an increased tendency toward developing edema.

ANS: B

The elderly are at higher risk for dehydration due to a decrease in muscle mass. The elderly have a decrease in total body water and thirst. The increased tendency to develop edema is not related to dehydration.

REF:   p. 131, Geriatric Considerations

4.   Which of the following patients should the nurse assess for decreased oncotic pressure in the capillaries? A patient with:

a.   a high-protein diet.

b.   liver failure.

c.   low blood pressure.

d.   low blood glucose.

ANS: B

Liver failure leads to lost or diminished plasma albumin production, and this contributes to decreased plasma oncotic pressure. A high-protein diet would provide albumin for the maintenance of oncotic pressure. Low blood pressure would lead to decreased hydrostatic pressure. Decreased glucose does not affect oncotic pressure.

REF:   p. 116

5.   Water movement between the ICF and ECF compartments is determined by:

a.   osmotic forces.

b.   plasma oncotic pressure.

c.   antidiuretic hormone.

d.   buffer systems.

ANS: A

Osmotic forces determine water movement between the ECF and ICF compartments. Oncotic pressure pulls water at the end of the capillary, which makes it move between intra and extra as interstitial is considered extra. The antidiuretic hormone regulates water balance,which would make water move between the intra- and extracellular spaces. Buffer systems help regulate acid balance.

REF:   p. 115

6.   An experiment was designed to test the effects of the Starling forces on fluid movement.

Which of the following alterations would result in fluid moving into the interstitial space?

a.   Increased capillary oncotic pressure.

b.   Increased interstitial hydrostatic pressure.

c.   Decreased capillary hydrNosUtaRticSpIreNsGsuTreB. .COM

d.   Increased interstitial oncotic pressure.

ANS: D

Increased interstitial oncotic pressure would attract water from the capillary into the interstitial space. Increased capillary oncotic pressure would attract water from the interstitial space back into the capillary. Increased interstitial hydrostatic pressure would attract movement of water from the interstitial spaces into the capillary. Decreased capillary hydrostatic pressure would move water into the capillaries.

REF:   p. 115

7.   When planning care for a dehydrated patient, the nurse remembers that the principle of water balance is closely related to the balance of:

a.   potassium.

b.   chloride.

c.   bicarbonate.

d.   sodium.

ANS: D

Because water follows the osmotic gradients established by changes in salt concentration, water balance is tied to sodium balance, not that of potassium, chloride, or bicarbonate.

REF:   pp. 116-117 | p. 118, Figure 5-5

8.   A 70-year-old male with chronic renal failure presents with edema. Which of the following is the most likely cause of this condition?

a.   Increased capillary oncotic pressure.

b.   Decreased interstitial oncotic pressure.

c.   Increased capillary hydrostatic pressure.

d.   Increased interstitial hydrostatic pressure.

ANS: C

Increased capillary hydrostatic pressure would facilitate increased movement from the capillary to the interstitial space, leading to edema. Increased capillary (plasma) oncotic pressure attracts water from the interstitial space back into the capillary. Decreased interstitial oncotic pressure would keep water in the capillary. Increased interstitial hydrostatic pressure would facilitate increased water movement from the interstitial space into the capillary.

REF:   pp. 115-116

9.   A 10-year-old male is brought to the emergency room (ER) incoherent and semiconscious. CT

scan reveals that he is suffering from cerebral edema. This type of edema is referred to as:

a.   localized edema.

b.   generalized edema.

c.   pitting edema.

d.   lymphedema.

ANS: A

Cerebral edema is a form of localized edema. Generalized edema is manifested by a more uniform distribution of fluid in interstitial spaces. When pressure is applied, pitting edema results in an indention in the skin. Lymphedema is due to swelling in interstitial spaces, primarily in the extremities.

REF:   p. 116

10.   A nurse is teaching the staff about antidiuretic hormone (ADH). Which information should the nurse include? Secretion of ADH is stimulated by:

a.   increased serum potassium.

b.   increased plasma osmolality.

c.   decreased renal blood flow.

d.   generalized edema.

ANS: B

ADH is secreted when plasma osmolality increases or circulating blood volume decreases and blood pressure drops. ADH is not secreted by an increase in potassium, a decrease in renal blood flow, or the presence of generalized edema.

REF:   p. 118

11.   Which statement by the staff indicates teaching was successful concerning aldosterone?

Secretion of aldosterone results in:

a.   decreased plasma osmolality.

b.   increased serum potassium levels.

c.   increased blood volume.

d.   localized edema.

ANS: C

Aldosterone promotes renal sodium and water reabsorption and excretion of potassium, thus increasing blood volume. Aldosterone secretion would cause increased plasma osmolality but it does not promote the development of localized edema; it affects blood volume.

REF:   p. 117

12.   A 25-year-old male is diagnosed with a hormone-secreting tumor of the adrenal cortex. Which finding would the nurse expect to see in the lab results?

a.   Decreased blood volume

b.   Decreased blood K+ levels c.   Increased urine Na+ levels d.   Increased white blood cells

ANS: B

Aldosterone is secreted from the adrenal cortex. It promotes renal sodium and water reabsorption and excretion of potassium, leading to decreased potassium levels. Blood volume actually increases with aldosterone secretion. Aldosterone promotes sodium reabsorption, leading to normal or decreased Na+ levels, and is not associated with white blood cells.

REF:   p. 117

13.   A patient has been searching on the Internet about natriuretic hormones. When the patient asks the nurse what these hormones do, how should the nurse respond? Natriuretic hormones affect the balance of:

a.   calcium.

b.   sodium.

c.   magnesium.

d.   potassium.

ANS: B

Natriuretic hormones are sometimes called a “third factor” in sodium regulation but have no influence on calcium, magnesium, or potassium balance.

REF:   p. 117

14.   A 5-year-old male presents to the ER with delirium and sunken eyes. After diagnosing him with severe dehydration, the primary care provider orders fluid replacement. The nurse administers a hypertonic intravenous solution. Which of the following would be expected? a.        Symptoms subside quickly

b.   Increased ICF volume

c.   Decreased ECF volume

d.   Intracellular dehydration

ANS: D

A hypertonic solution would cause fluid to move into the extracellular space, leading to intracellular dehydration. With this solution, his symptoms will not subside quickly because his cells will lose fluid. His intracellular volume will decrease and his extracellular volume will increase.

REF:   p. 120

15.   Which of the following patients is the most at risk for developing hypernatremia? A patient with:

a.   vomiting.

b.   diuretic use.

c.   dehydration.

d.   hypoaldosteronism.

ANS: C

Dehydration leads to hypernatremia because an increase in sodium occurs with a net loss in water. Vomiting and diuretic use leads to hyponatremia. Hypoaldosteronism leads to hyponatremia.

REF:   p. 119

16.   Which of the following conditions would cause the nurse to monitor for hyperkalemia?

a.   Excess aldosterone

b.   Acute acidosis

c.   Insulin usage

d.   Metabolic alkalosis

ANS: B

In acidosis, ECF hydrogen ions shift into the cells in exchange for ICF potassium and sodium; hyperkalemia and acidosis therefore often occur together. Acidosis does not cause excess aldosterone. Insulin would help treat hyperkalemia, not cause it.

Alkalosis does not lead to hyperkalemia.

REF:   p. 124

17.   Which organ system should the nurse monitor when the patient has long-term potassium

deficits?

a.   Central nervous system (CNS)

b.   Lungs

c.   Kidneys

d.   Gastrointestinal tract

ANS: C

Long-term potassium deficits lasting more than 1 month may damage renal tissue, with interstitial fibrosis and tubular atrophy. Long-term potassium deficits are not associated with damage to the CNS, GI tract, or lungs.

REF:   pp. 123-124

18.   A 42-year-old female presents to her primary care provider reporting muscle weakness and cardiac abnormalities. Laboratory tests indicate that she is hypokalemic. Which of the following could be the cause of her condition?

a.   Respiratory acidosis

b.   Constipation

c.   Hypoglycemia

d.   Laxative abuse

ANS: D

Losses of potassium from body stores are usually caused by gastrointestinal and renal disorders. Diarrhea, intestinal drainage tubes or fistulae, and laxative abuse also result in hypokalemia. Acidosis is related to hyperkalemia, not hypokalemia. Constipation can occur with hypokalemia but does not cause it. Hypoglycemia is not related to muscle weakness.

REF:   p. 123

19.   A 19-year-old male presents to his primary care provider reporting restlessness, muscle cramping, and diarrhea. Lab tests reveal that he is hyperkalemic. Which of the followingcould have caused his condition?

a.   Primary hyperaldosteronism

b.   Acidosis

c.   Insulin secretion

d.   Diuretic use

ANS: B

During acute acidosis, hydrogen ions accumulate in the ICF and potassium shifts out of the cell to the ECF, causing hyperkalemia. Primary hyperaldosteronism is associated with hypokalemia, not hyperkalemia. Insulin secretion helps reduce potassium levels in the cell; it does not cause hyperkalemia. Diuretics would cause hypokalemia, not hyperkalemia.

REF:   p. 122

20.   A 60-year-old female is diagnosed with hyperkalemia. Which assessment finding should the nurse expect to observe?

a.   Weak pulse

b.   Excessive thirst

c.   Oliguria

d.   Constipation

ANS: C

Hyperkalemia is manifested by oliguria. Hypokalemia is manifested by a weak pulse; it is not caused by hyperkalemia. Hypokalemia is manifested by excessive thirst. Diarrhea, not constipation, is a manifestation of hyperkalemia.

REF:   p. 124, Table 5-6

21.   Which of the following buffer pairs is considered the major plasma buffering system?

a.   Protein/fat

b.   Carbonic acid/bicarbonate

c.   Sodium/potassium

d.   Amylase/albumin

ANS: B

The carbonic acid/bicarbonate buffer pair operates in both the lung and the kidney and is a major extracellular buffer. Protein and fat are nutrients not related to the buffering system. Sodium and potassium are electrolytes for fluid and electrolyte balance, not the major plasma buffering system for acid-base balance. Amylase is a carbohydrate enzyme, and albumin is a protein; neither is a buffering system.

REF:   p. 125

22.   A nurse recalls that regulation of acid-base balance through removal or retention of volatile acids is accomplished by the:

a.   buffer systems.

b.   skin.

c.   lungs.

d.   liver.

ANS: C

The volatile acid is carbonic acid (H2CO3), which readily dissociates into carbon dioxide (CO2) and water (H2O). The CO2 is then eliminated by the lungs. Buffer systems are throughout the body and operate in the extracellular and intracellular systems. Neither the liver nor the skin regulates acid-base balance.

REF:   p. 125

23.   Which patient is most prone to metabolic alkalosis? A patient with:

a.   retention of metabolic acids.

b.   hypoaldosteronism.

c.   excessive loss of chloride (Cl).

d.   hyperventilation.

ANS: C

When acid loss is caused by vomiting, renal compensation is not very effective because loss of Cl stimulates renal retention of bicarbonate, leading to alkalosis. Retention of metabolic acids would lead to acidosis, not alkalosis. Hypoaldosteronism leads to hyponatremia and does not cause alkalosis. Hyperventilation leads to respiratory alkalosis, not metabolic alkalosis.

REF:   p. 127

24.   Which patient should the nurse assess for both hyperkalemia and metabolic acidosis? A

patient diagnosed with:

a.   diabetes insipidus.

b.   pulmonary disorders.

c.   Cushing syndrome.

d.   renal failure.

ANS: D

Renal failure is associated with hyperkalemia and metabolic acidosis. Diabetes insipidus results in hypernatremia. Pulmonary disorders are a cause of respiratory acidosis or alkalosis but do not affect hyperkalemia. Cushing syndrome results in hypernatremia.

REF:   p. 124 | p. 127

25.   For a patient experiencing metabolic acidosis, the body will compensate by:

a.   excreting H+ through the kidneys.

b.   hyperventilating.

c.   retaining CO2  in the lungs.

d.   secreting aldosterone.

ANS: B

It is the lungs hyperventilating that would compensate for metabolic acidosis by blowing off CO2, not any function associated with the kidneys. CO2 retention would increase the acidotic state. Aldosterone would conserve water but does not help compensate for acidosis.

REF:   p. 127

26.   Which finding would support the diagnosis of respiratory acidosis?

a.   Vomiting

b.   Hyperventilation

c.   Pneumonia

d.   An increase in noncarbonic acids

ANS: C

Respiratory acidosis occurs with hypoventilation, and pneumonia leads to hypoventilation. Vomiting leads to loss of acids and then to alkalosis. Hyperventilation leads to respiratory alkalosis. Metabolic acidosis is caused by an increase in noncarbonic acids.

REF:   pp. 128-129

27.   A 54-year-old male with a long history of smoking complains of excessive tiredness, shortness of breath, and overall ill feelings. Lab results reveal decreased pH, increased CO2,and normal bicarbonate ion. These findings help to confirm the diagnosis of:

a.   respiratory alkalosis.

b.   metabolic acidosis. c.   respiratory acidosis. d.   metabolic alkalosis.

ANS: C

A decreased pH indicates acidosis. With increased CO2, it is respiratory acidosis. The bicarbonate is normal, so it cannot be metabolic acidosis.

REF:   pp. 128-129

28.   For a patient with respiratory acidosis, chronic compensation by the body will include:

a.   kidney excretion of H+.

b.   kidney excretion of HCO3.

c.   prolonged exhalations to blow off CO2.

d.   protein buffering.

ANS: A

The kidneys excrete H+ to compensate for respiratory acidosis. The kidneys do not excrete

HCO3 to compensate; this would increase acidosis. Prolonged exhalations would not be effective for compensation, especially in a chronic state. Protein buffering is intracellular and would not be effective enough to compensate for respiratory acidosis.

REF:   pp. 128-130

29.   A 55-year-old female presents to her primary care provider and reports dizziness, confusion, and tingling in the extremities. Blood tests reveal an elevated pH, decreased PCO2, and slightly decreased HCO3. Which of the following is the most likely diagnosis?

a.   Respiratory alkalosis with renal compensation

b.   Respiratory acidosis with renal compensation

c.   Metabolic alkalosis with respiratory compensation

d.   Metabolic acidosis with respiratory compensation

ANS: A

With an elevated pH, the diagnosis must be alkalosis. Since the PCO2  is low, it is likely respiratory, with a slight decrease in HCO3  indicating renal compensation.

REF:   p. 130

MULTIPLE RESPONSE

1.   A 60-year-old male with a 30-year history of smoking is diagnosed with a hormone-secreting lung tumor. Further testing indicates that the tumor secretes ADH. Which of the following assessment findings should the nurse expect? (select all that apply)

a.   Confusion

b.   Weakness

c.   Nausea

d.   Muscle twitching

e.   Increased reflexes

ANS: A, B, C, D

Secretion of ADH leads to water intoxication with symptoms of cerebral edema, including confusion, convulsions, weakness, nausea, and muscle twitching. Depressed reflexes are associated with water intoxication.