Potter-Perry Chapter 42 Electrolytes and Fluid
Balance UPDATED ACTUAL Questions and
CORRECT Answers
1. Approximately two thirds of the body's total water volume exists in the _____ fluid.
a. Intracellular
b. Interstitial
c. Intravascular
d. Transcellular - CORRECT ANSWER A
(Intracellular fluid accounts for approximately two thirds of the fluids in the body—about 42% of total body weight.
Interstitial fluid, intravascular fluid, and transcellular fluid constitute extra-cellular fluid, which is the fluid outside a cell.)
2. The process of passively moving water from an area of lower particle concentration to an area of higher particle
concentration is known as
a. Hydrolysis.
b. Osmosis.
c. Filtration.
d. Active transport. - CORRECT ANSWER B
(The process of moving water from an area of low particle concentration to an area of higher par-ticle concentration is
known as osmosis. Hydrolysis is not a term related to fluid and electrolyte balance. Filtration is mediated by fluid
pressure from an area of higher pressure to an area of lower pressure. Active transport requires metabolic activity and is
not passive.)
3. The nurse knows that edema in a patient who has venous congestion from right heart failure is facilitated by an
imbalance with regard to _____ pressure.
a. Hydrostatic
b. Osmotic
c. Oncotic
d. Concentration - CORRECT ANSWER A
(Venous congestion increases capillary hydrostatic pressure. Increased hydrostatic pressure causes edema by causing
increased movement of fluid into the interstitial area. Osmotic and oncotic pressures involve the concentrations of solutes
and can contribute to edema in other situations. Concentration pressure is not a nursing term.)
4. The nurse understands that administering a hypertonic solution to a patient will shift wa-ter from the _____ to the
_____ space.
a. Intracellular; extracellular
b. Extracellular; intracellular
c. Intravascular; intracellular
d. Intravascular; interstitial - CORRECT ANSWER A
(A hypertonic solution has a concentration greater than normal body fluids, so water will shift out of cells because of the
osmotic pull of the extra particles. Movement of water into cells occurs when hypotonic fluids are administered.
Distribution of fluid between intravascular and intersti-tial spaces occurs by filtration, the net sum of hydrostatic and
osmotic pressures.)
5. Which patient is most at risk for sensible water loss?
a. A 7-year-old child with asthma
b. A 24-year-old adult with constipation
c. A 56-year-old patient with gastroenteritis
d. An 80-year-old patient with pneumonia - CORRECT ANSWER D
(Sensible water loss consists of fluids lost from the skin through visible perspiration, such as with a resolving fever
related to pneumonia. Asthma would be insensible water loss through respira-tion. Gastroenteritis causes diarrhea with its
large volume loss. Constipation does not affect fluid loss.)
6. The nurse knows that the most abundant cation in the blood is
a. Sodium.
b. Potassium.
c. Chloride.
d. Magnesium. - CORRECT ANSWER A
, (Sodium is the most abundant cation in the blood. Potassium is the predominant intracellular cat-ion. Chloride is an anion
-negatively charged- rather then a cation -positively charged-. Magne-sium is found predominantly inside cells and in
bone.)
7. The nurse receives the patient's most recent blood work results. Which laboratory value is of greatest concern?
a. Sodium of 145 mEq/L
b. Calcium of 17.5 mg/dL
c. Potassium of 3.5 mEq/L
d. Chloride of 100 mEq/L - CORRECT ANSWER B
(Normal calcium range is 8.5 mg/dL to 10.5 mg/dL; therefore, a value of 17.5 mg/dL is abnormal-ly high and of concern.
The rest of the laboratory values are within their normal ranges: sodium 135 to 145 mEq/L; potassium 3.5 to 5.0 mEq/L;
chloride 98 to 106 mEq/L.)
8. The nurse would expect a patient with increased levels of serum calcium to also have _____ levels.
a. Increased potassium
b. Decreased phosphate
c. Decreased sodium
d. Increased magnesium - CORRECT ANSWER B
(Serum calcium and phosphate have an inverse relationship. When one is elevated, the other de-creases, except in some
patients with end-stage renal disease. Increased serum calcium would not necessarily cause changes in levels of
potassium, sodium, or magnesium.)
9. The nurse knows that an imbalance of which ion causes acid-base impairment?
a. Hydrogen
b. Calcium
c. Magnesium
d. Sodium - CORRECT ANSWER A
(The concentration of hydrogen ions determines pH. Low pH designates an acidic environment. High pH designates an
alkaline environment. Calcium, magnesium, and sodium are ions, but their imbalances are not direct acid-base
impairments.)
10. The nurse would expect a patient with respiratory acidosis to have an excessive amount of
a. Carbon dioxide.
b. Bicarbonate.
c. Oxygen.
d. Phosphate. - CORRECT ANSWER A
(Respiratory acidosis occurs when the lungs are not able to excrete enough carbon dioxide. Car-bon dioxide and water
create carbonic acid. A buildup of carbonic acid causes the ECF to be-come more acidic, decreasing the pH. Bicarbonate
is normal with uncompensated respiratory ac-idosis or elevated with compensated respiratory acidosis. Excessive oxygen
and phosphate are not characteristic of respiratory acidosis.)
11. A 2-year-old child was brought into the emergency department after ingesting several morphine tablets from a bottle
in his mother's purse. The nurse knows that the child is at greatest risk for which acid-base imbalance?
a. Respiratory acidosis
b. Respiratory alkalosis
c. Metabolic acidosis
d. Metabolic alkalosis - CORRECT ANSWER A
(Morphine overdose can cause respiratory depression and hypoventilation. Hypoventilation results in retention of CO2
and respiratory acidosis. Respiratory alkalosis would result from hyperventi-lation, causing a decrease in CO2 levels.
Metabolic acid-base imbalance would be a result of kid-ney dysfunction, vomiting, diarrhea, or other conditions that
affect metabolic acids.)
12. A patient was admitted for a bowel obstruction and has had a nasogastric tube set to low intermittent suction for the
past 3 days. The patient's respiratory rate has decreased to 12 breaths per minute. The nurse would expect the patient to
have which of the following arterial blood gas values?
a. pH 7.78, PaCO2 40 mm Hg, HCO3- 30 mEq/L
b. pH 7.52, PaCO2 48 mm Hg, HCO3- 28 mEq/L
c. pH 7.35, PaCO2 35 mm Hg, HCO3- 26 mEq/L
d. pH 7.25, PaCO2 47 mm Hg, HCO3- 29 mEq/L - CORRECT ANSWER B
(Compensated metabolic alkalosis should show alkalosis pH and HCO3- -metabolic- values, with a slightly acidic CO2 -
compensatory respiratory acidosis-. In this case, pH 7.52 is alkaline -normal = 7.35 to 7.45-, PaCO2 is acidic -normal 35
Balance UPDATED ACTUAL Questions and
CORRECT Answers
1. Approximately two thirds of the body's total water volume exists in the _____ fluid.
a. Intracellular
b. Interstitial
c. Intravascular
d. Transcellular - CORRECT ANSWER A
(Intracellular fluid accounts for approximately two thirds of the fluids in the body—about 42% of total body weight.
Interstitial fluid, intravascular fluid, and transcellular fluid constitute extra-cellular fluid, which is the fluid outside a cell.)
2. The process of passively moving water from an area of lower particle concentration to an area of higher particle
concentration is known as
a. Hydrolysis.
b. Osmosis.
c. Filtration.
d. Active transport. - CORRECT ANSWER B
(The process of moving water from an area of low particle concentration to an area of higher par-ticle concentration is
known as osmosis. Hydrolysis is not a term related to fluid and electrolyte balance. Filtration is mediated by fluid
pressure from an area of higher pressure to an area of lower pressure. Active transport requires metabolic activity and is
not passive.)
3. The nurse knows that edema in a patient who has venous congestion from right heart failure is facilitated by an
imbalance with regard to _____ pressure.
a. Hydrostatic
b. Osmotic
c. Oncotic
d. Concentration - CORRECT ANSWER A
(Venous congestion increases capillary hydrostatic pressure. Increased hydrostatic pressure causes edema by causing
increased movement of fluid into the interstitial area. Osmotic and oncotic pressures involve the concentrations of solutes
and can contribute to edema in other situations. Concentration pressure is not a nursing term.)
4. The nurse understands that administering a hypertonic solution to a patient will shift wa-ter from the _____ to the
_____ space.
a. Intracellular; extracellular
b. Extracellular; intracellular
c. Intravascular; intracellular
d. Intravascular; interstitial - CORRECT ANSWER A
(A hypertonic solution has a concentration greater than normal body fluids, so water will shift out of cells because of the
osmotic pull of the extra particles. Movement of water into cells occurs when hypotonic fluids are administered.
Distribution of fluid between intravascular and intersti-tial spaces occurs by filtration, the net sum of hydrostatic and
osmotic pressures.)
5. Which patient is most at risk for sensible water loss?
a. A 7-year-old child with asthma
b. A 24-year-old adult with constipation
c. A 56-year-old patient with gastroenteritis
d. An 80-year-old patient with pneumonia - CORRECT ANSWER D
(Sensible water loss consists of fluids lost from the skin through visible perspiration, such as with a resolving fever
related to pneumonia. Asthma would be insensible water loss through respira-tion. Gastroenteritis causes diarrhea with its
large volume loss. Constipation does not affect fluid loss.)
6. The nurse knows that the most abundant cation in the blood is
a. Sodium.
b. Potassium.
c. Chloride.
d. Magnesium. - CORRECT ANSWER A
, (Sodium is the most abundant cation in the blood. Potassium is the predominant intracellular cat-ion. Chloride is an anion
-negatively charged- rather then a cation -positively charged-. Magne-sium is found predominantly inside cells and in
bone.)
7. The nurse receives the patient's most recent blood work results. Which laboratory value is of greatest concern?
a. Sodium of 145 mEq/L
b. Calcium of 17.5 mg/dL
c. Potassium of 3.5 mEq/L
d. Chloride of 100 mEq/L - CORRECT ANSWER B
(Normal calcium range is 8.5 mg/dL to 10.5 mg/dL; therefore, a value of 17.5 mg/dL is abnormal-ly high and of concern.
The rest of the laboratory values are within their normal ranges: sodium 135 to 145 mEq/L; potassium 3.5 to 5.0 mEq/L;
chloride 98 to 106 mEq/L.)
8. The nurse would expect a patient with increased levels of serum calcium to also have _____ levels.
a. Increased potassium
b. Decreased phosphate
c. Decreased sodium
d. Increased magnesium - CORRECT ANSWER B
(Serum calcium and phosphate have an inverse relationship. When one is elevated, the other de-creases, except in some
patients with end-stage renal disease. Increased serum calcium would not necessarily cause changes in levels of
potassium, sodium, or magnesium.)
9. The nurse knows that an imbalance of which ion causes acid-base impairment?
a. Hydrogen
b. Calcium
c. Magnesium
d. Sodium - CORRECT ANSWER A
(The concentration of hydrogen ions determines pH. Low pH designates an acidic environment. High pH designates an
alkaline environment. Calcium, magnesium, and sodium are ions, but their imbalances are not direct acid-base
impairments.)
10. The nurse would expect a patient with respiratory acidosis to have an excessive amount of
a. Carbon dioxide.
b. Bicarbonate.
c. Oxygen.
d. Phosphate. - CORRECT ANSWER A
(Respiratory acidosis occurs when the lungs are not able to excrete enough carbon dioxide. Car-bon dioxide and water
create carbonic acid. A buildup of carbonic acid causes the ECF to be-come more acidic, decreasing the pH. Bicarbonate
is normal with uncompensated respiratory ac-idosis or elevated with compensated respiratory acidosis. Excessive oxygen
and phosphate are not characteristic of respiratory acidosis.)
11. A 2-year-old child was brought into the emergency department after ingesting several morphine tablets from a bottle
in his mother's purse. The nurse knows that the child is at greatest risk for which acid-base imbalance?
a. Respiratory acidosis
b. Respiratory alkalosis
c. Metabolic acidosis
d. Metabolic alkalosis - CORRECT ANSWER A
(Morphine overdose can cause respiratory depression and hypoventilation. Hypoventilation results in retention of CO2
and respiratory acidosis. Respiratory alkalosis would result from hyperventi-lation, causing a decrease in CO2 levels.
Metabolic acid-base imbalance would be a result of kid-ney dysfunction, vomiting, diarrhea, or other conditions that
affect metabolic acids.)
12. A patient was admitted for a bowel obstruction and has had a nasogastric tube set to low intermittent suction for the
past 3 days. The patient's respiratory rate has decreased to 12 breaths per minute. The nurse would expect the patient to
have which of the following arterial blood gas values?
a. pH 7.78, PaCO2 40 mm Hg, HCO3- 30 mEq/L
b. pH 7.52, PaCO2 48 mm Hg, HCO3- 28 mEq/L
c. pH 7.35, PaCO2 35 mm Hg, HCO3- 26 mEq/L
d. pH 7.25, PaCO2 47 mm Hg, HCO3- 29 mEq/L - CORRECT ANSWER B
(Compensated metabolic alkalosis should show alkalosis pH and HCO3- -metabolic- values, with a slightly acidic CO2 -
compensatory respiratory acidosis-. In this case, pH 7.52 is alkaline -normal = 7.35 to 7.45-, PaCO2 is acidic -normal 35
