NSG 3100 Exam 4 – Fluid & Electrolyte Balance
100 multiple-choice questions with correct answers and detailed rationales.
Covers potassium, sodium, calcium, magnesium, phosphate, chloride imbalances,
acid-base disorders (metabolic/respiratory acidosis/alkalosis), IV fluid therapy,
diuretic effects, clinical manifestations, nursing interventions, and priority
assessments. Designed for nursing students to reinforce critical thinking,
lab value interpretation, and safe patient care. Updated with latest evidence -based
content. Ideal for exam preparation and remediation.
1. The nurse is providing teaching to clients regarding intake of dietary potassium. The nurse
recognizes that the client at risk of developing an electrolyte imbalance of potassium is the
client who
a. has fatty stools from taking an over-the-counter (OTC) weight loss product.
b. experiences anorexia.
c. has chronic heart failure (HF) that is being treated with diuretics.
d. takes very large doses of vitamin D as a chemotherapy supplement.
Correct Answer: c. has chronic heart failure (HF) that is being treated with diuretics.
Rationale: Clients with chronic heart failure are frequently prescribed loop or thiazide diuretics
to reduce fluid volume overload. These medications promote renal excretion of potassium,
which directly increases the risk of hypokalemia. Although anorexia can reduce potassium
intake, it is not as direct or common a cause as diuretic therapy. Fatty stools indicate fat
[1]
,malabsorption, which affects fat-soluble vitamins (A, D, E, K), not potassium. Large doses of
vitamin D can lead to hypercalcemia, not potassium imbalance. Therefore, the client on
diuretics is at the highest risk for a potassium imbalance.
2. The nurse is caring for a client who has had diarrhea for 48 hours and has developed fatigue,
muscle weakness, and an irregular pulse. Which of the following laboratory results should the
nurse correlate to these signs and symptoms?
a. Serum phosphate of 4 mEq/L.
b. Serum magnesium of 2 mEq/L.
c. Serum calcium of 9.5 mEq/L.
d. Serum potassium of 2.8 mEq/L.
Correct Answer: d. Serum potassium of 2.8 mEq/L.
Rationale: Prolonged diarrhea causes significant gastrointestinal losses of potassium, leading to
hypokalemia. The classic signs of hypokalemia include fatigue, muscle weakness, and cardiac
dysrhythmias such as premature ventricular contractions or atrial fibrillation due to altered
myocardial irritability and repolarization. A serum potassium of 2.8 mEq/L is below the normal
range of 3.5–5.0 mEq/L, confirming hypokalemia. The other lab values are within normal limits:
phosphate 2.5–4.5 mg/dL, magnesium 1.3–2.1 mEq/L, and calcium 8.5–10.5 mg/dL. Thus, the
potassium level directly correlates with the client's presentation.
3. The nurse is caring for a client who has multiple draining wounds and has been admitted for
hypovolemia. Which of the following assessment findings is consistent with hypovolemia?
a. Increased urine output.
b. Decreased skin turgor.
c. Hypertension.
d. Bounding peripheral pulses.
Correct Answer: b. Decreased skin turgor.
[2]
,Rationale: Hypovolemia is characterized by a deficit of intravascular fluid volume. Decreased
skin turgor, often assessed by tenting of the skin over the sternum or forehead, is a classic sign
because the skin loses its elasticity due to reduced interstitial fluid. In hypovolemia, urine
output typically decreases, not increases, as the kidneys attempt to conserve fluid. Blood
pressure is usually low (hypotension), not hypertensive. Peripheral pulses are weak and
thready, not bounding, because of reduced stroke volume and cardiac output. Therefore,
decreased skin turgor is the finding most consistent with hypovolemia.
4. The nurse is caring for assigned clients. The nurse should see the client with which of the
following symptoms first?
a. Serum potassium concentration is decreasing; abdominal distention, but denies any
difficulty breathing.
b. Serum calcium concentration is increasing; reports constipation; is alert and denies any
discomfort.
c. Serum potassium concentration is increasing; has developed cardiac dysrhythmias, but
denies any difficulty breathing.
d. Serum calcium concentration is decreasing; reports constipation; is alert and reports a pain
level of 3 on a scale of 0 (no pain) to 10 (severe pain).
Correct Answer: c. Serum potassium concentration is increasing; has developed cardiac
dysrhythmias, but denies any difficulty breathing.
Rationale: Hyperkalemia (increasing serum potassium) is a life-threatening electrolyte
imbalance because it can cause fatal cardiac dysrhythmias, including ventricular fibrillation and
asystole. The presence of cardiac dysrhythmias indicates that the hyperkalemia is already
affecting the heart, requiring immediate intervention regardless of the absence of respiratory
distress. Hypokalemia with abdominal distention (option a) is concerning but less immediately
life-threatening. Hypercalcemia with constipation (option b) and hypocalcemia with
constipation and mild pain (option d) are serious but do not carry the same immediate risk of
sudden cardiac death. Thus, the client with hyperkalemia and cardiac dysrhythmias must be
seen first.
[3]
, 5. The nurse is caring for the following clients. The nurse identifies which client as being at risk
for developing metabolic acidosis?
a. The client who is extremely anxious.
b. The client who has had diarrhea for over a week.
c. The client who has a nasogastric (NG) tube.
d. The client who has newly diagnosed pneumonia.
Correct Answer: b. The client who has had diarrhea for over a week.
Rationale: Prolonged diarrhea leads to excessive loss of bicarbonate-rich intestinal fluid,
resulting in metabolic acidosis. The normal GI tract secretes and reabsorbs bicarbonate; when
diarrhea occurs, this bicarbonate is lost, causing a decrease in serum pH. Extreme anxiety leads
to respiratory alkalosis due to hyperventilation, not metabolic acidosis. NG tube suctioning
removes gastric acid (HCl), leading to metabolic alkalosis, not acidosis. Pneumonia can cause
respiratory acidosis due to impaired gas exchange and CO2 retention, but it is a respiratory, not
metabolic, acid-base disturbance. Therefore, the client with prolonged diarrhea is at risk for
metabolic acidosis.
6. The nurse is assessing a client with severe vomiting for 3 days. Which acid-base imbalance is
this client most at risk for developing?
a. Metabolic acidosis.
b. Metabolic alkalosis.
c. Respiratory acidosis.
d. Respiratory alkalosis.
Correct Answer: b. Metabolic alkalosis.
[4]
100 multiple-choice questions with correct answers and detailed rationales.
Covers potassium, sodium, calcium, magnesium, phosphate, chloride imbalances,
acid-base disorders (metabolic/respiratory acidosis/alkalosis), IV fluid therapy,
diuretic effects, clinical manifestations, nursing interventions, and priority
assessments. Designed for nursing students to reinforce critical thinking,
lab value interpretation, and safe patient care. Updated with latest evidence -based
content. Ideal for exam preparation and remediation.
1. The nurse is providing teaching to clients regarding intake of dietary potassium. The nurse
recognizes that the client at risk of developing an electrolyte imbalance of potassium is the
client who
a. has fatty stools from taking an over-the-counter (OTC) weight loss product.
b. experiences anorexia.
c. has chronic heart failure (HF) that is being treated with diuretics.
d. takes very large doses of vitamin D as a chemotherapy supplement.
Correct Answer: c. has chronic heart failure (HF) that is being treated with diuretics.
Rationale: Clients with chronic heart failure are frequently prescribed loop or thiazide diuretics
to reduce fluid volume overload. These medications promote renal excretion of potassium,
which directly increases the risk of hypokalemia. Although anorexia can reduce potassium
intake, it is not as direct or common a cause as diuretic therapy. Fatty stools indicate fat
[1]
,malabsorption, which affects fat-soluble vitamins (A, D, E, K), not potassium. Large doses of
vitamin D can lead to hypercalcemia, not potassium imbalance. Therefore, the client on
diuretics is at the highest risk for a potassium imbalance.
2. The nurse is caring for a client who has had diarrhea for 48 hours and has developed fatigue,
muscle weakness, and an irregular pulse. Which of the following laboratory results should the
nurse correlate to these signs and symptoms?
a. Serum phosphate of 4 mEq/L.
b. Serum magnesium of 2 mEq/L.
c. Serum calcium of 9.5 mEq/L.
d. Serum potassium of 2.8 mEq/L.
Correct Answer: d. Serum potassium of 2.8 mEq/L.
Rationale: Prolonged diarrhea causes significant gastrointestinal losses of potassium, leading to
hypokalemia. The classic signs of hypokalemia include fatigue, muscle weakness, and cardiac
dysrhythmias such as premature ventricular contractions or atrial fibrillation due to altered
myocardial irritability and repolarization. A serum potassium of 2.8 mEq/L is below the normal
range of 3.5–5.0 mEq/L, confirming hypokalemia. The other lab values are within normal limits:
phosphate 2.5–4.5 mg/dL, magnesium 1.3–2.1 mEq/L, and calcium 8.5–10.5 mg/dL. Thus, the
potassium level directly correlates with the client's presentation.
3. The nurse is caring for a client who has multiple draining wounds and has been admitted for
hypovolemia. Which of the following assessment findings is consistent with hypovolemia?
a. Increased urine output.
b. Decreased skin turgor.
c. Hypertension.
d. Bounding peripheral pulses.
Correct Answer: b. Decreased skin turgor.
[2]
,Rationale: Hypovolemia is characterized by a deficit of intravascular fluid volume. Decreased
skin turgor, often assessed by tenting of the skin over the sternum or forehead, is a classic sign
because the skin loses its elasticity due to reduced interstitial fluid. In hypovolemia, urine
output typically decreases, not increases, as the kidneys attempt to conserve fluid. Blood
pressure is usually low (hypotension), not hypertensive. Peripheral pulses are weak and
thready, not bounding, because of reduced stroke volume and cardiac output. Therefore,
decreased skin turgor is the finding most consistent with hypovolemia.
4. The nurse is caring for assigned clients. The nurse should see the client with which of the
following symptoms first?
a. Serum potassium concentration is decreasing; abdominal distention, but denies any
difficulty breathing.
b. Serum calcium concentration is increasing; reports constipation; is alert and denies any
discomfort.
c. Serum potassium concentration is increasing; has developed cardiac dysrhythmias, but
denies any difficulty breathing.
d. Serum calcium concentration is decreasing; reports constipation; is alert and reports a pain
level of 3 on a scale of 0 (no pain) to 10 (severe pain).
Correct Answer: c. Serum potassium concentration is increasing; has developed cardiac
dysrhythmias, but denies any difficulty breathing.
Rationale: Hyperkalemia (increasing serum potassium) is a life-threatening electrolyte
imbalance because it can cause fatal cardiac dysrhythmias, including ventricular fibrillation and
asystole. The presence of cardiac dysrhythmias indicates that the hyperkalemia is already
affecting the heart, requiring immediate intervention regardless of the absence of respiratory
distress. Hypokalemia with abdominal distention (option a) is concerning but less immediately
life-threatening. Hypercalcemia with constipation (option b) and hypocalcemia with
constipation and mild pain (option d) are serious but do not carry the same immediate risk of
sudden cardiac death. Thus, the client with hyperkalemia and cardiac dysrhythmias must be
seen first.
[3]
, 5. The nurse is caring for the following clients. The nurse identifies which client as being at risk
for developing metabolic acidosis?
a. The client who is extremely anxious.
b. The client who has had diarrhea for over a week.
c. The client who has a nasogastric (NG) tube.
d. The client who has newly diagnosed pneumonia.
Correct Answer: b. The client who has had diarrhea for over a week.
Rationale: Prolonged diarrhea leads to excessive loss of bicarbonate-rich intestinal fluid,
resulting in metabolic acidosis. The normal GI tract secretes and reabsorbs bicarbonate; when
diarrhea occurs, this bicarbonate is lost, causing a decrease in serum pH. Extreme anxiety leads
to respiratory alkalosis due to hyperventilation, not metabolic acidosis. NG tube suctioning
removes gastric acid (HCl), leading to metabolic alkalosis, not acidosis. Pneumonia can cause
respiratory acidosis due to impaired gas exchange and CO2 retention, but it is a respiratory, not
metabolic, acid-base disturbance. Therefore, the client with prolonged diarrhea is at risk for
metabolic acidosis.
6. The nurse is assessing a client with severe vomiting for 3 days. Which acid-base imbalance is
this client most at risk for developing?
a. Metabolic acidosis.
b. Metabolic alkalosis.
c. Respiratory acidosis.
d. Respiratory alkalosis.
Correct Answer: b. Metabolic alkalosis.
[4]
