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NUR 170 – Complete Practice Test (2026) Questions and Answers with
100% Verified Correct Rationales | 2026 Updated | 100% correct
Detailed rationales are provided to reinforce clinical reasoning.
EXAM 1: Fluid & Electrolytes, Acid-Base Balances, and Perioperative Nursing
1. A patient is admitted with severe vomiting and diarrhea for 3 days. The nurse
suspects the patient is experiencing which type of fluid volume deficit?
A) Hypervolemia
B) Hypovolemia (isotonic dehydration)
C) Hypernatremia
D) Hyperkalemia
Answer: B
Rationale: Vomiting and diarrhea cause the loss of water and electrolytes in equal
proportions, leading to isotonic dehydration (hypovolemia). The body loses both
sodium and water, so the serum sodium remains normal, but total blood volume
drops.
2. The nurse is assessing a patient with severe dehydration. Which of the
following findings is a late sign of hypovolemic shock?
A) Tachycardia
B) Hypotension and decreased level of consciousness
C) Dry mucous membranes
D) Oliguria (decreased urine output)
Answer: B
Rationale: Tachycardia, dry mucous membranes, and oliguria are early
compensatory signs of hypovolemia. Hypotension and decreased level of
consciousness are late signs indicating that the body can no longer compensate,
and the patient is in decompensated shock.
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3. The nurse is caring for a patient who has a nasogastric (NG) tube to low
intermittent suction. The patient is at highest risk for which electrolyte
imbalance?
A) Hyperkalemia
B) Hypokalemia (due to loss of gastric acids and potassium)
C) Hypercalcemia
D) Hyponatremia
Answer: B
Rationale: NG tube suction removes gastric juices, which are rich in hydrochloric
acid (HCl) and potassium. Prolonged suction leads to metabolic alkalosis (loss of
acid) and hypokalemia (loss of potassium).
4. A patient is prescribed 0.9% Normal Saline (NS) IV. The nurse understands
that this fluid is:
A) Hypotonic
B) Isotonic (expands intravascular volume without shifting fluid into cells)
C) Hypertonic
D) A colloid
Answer: B
Rationale: 0.9% Normal Saline has an osmolarity of 308 mOsm/L, which is close to
the normal serum osmolarity (275-295 mOsm/L). It is an isotonic fluid used to
expand the intravascular volume.
5. A patient's arterial blood gas (ABG) results show: pH 7.30, PaCO₂ 50 mmHg,
HCO₃⁻ 24 mEq/L. What is the acid-base disturbance?
A) Metabolic acidosis
B) Respiratory acidosis (the pH is low, PaCO₂ is high, and HCO₃⁻ is normal)
C) Metabolic alkalosis
D) Respiratory alkalosis
Answer: B
Rationale: The pH is low (acidemia). The PaCO₂ is high (> 45 mmHg), indicating a
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respiratory cause. The HCO₃⁻ is normal (22-26 mEq/L). This is respiratory acidosis,
likely due to hypoventilation.
6. The nurse is caring for a patient with respiratory acidosis. Which of the
following nursing interventions is a priority?
A) Administer sodium bicarbonate IV.
B) Encourage the patient to breathe slowly.
C) Improve the patient's ventilation and airway clearance (e.g., reposition,
stimulate coughing, or prepare for mechanical ventilation).
D) Administer a sedative.
Answer: C
Rationale: Respiratory acidosis is caused by CO₂ retention due to hypoventilation.
The priority is to improve ventilation by repositioning the patient, encouraging
deep breathing, suctioning secretions, or preparing for mechanical ventilation.
7. A patient with diabetic ketoacidosis (DKA) presents with deep, rapid
respirations (Kussmaul respirations). The ABG shows pH 7.25, PaCO₂ 30 mmHg,
HCO₃⁻ 12 mEq/L. What is the acid-base disturbance?
A) Respiratory acidosis
B) Metabolic acidosis with respiratory compensation (the low HCO₃⁻ indicates
metabolic acidosis; the low PaCO₂ indicates the lungs are blowing off CO₂ to
compensate)
C) Metabolic alkalosis
D) Respiratory alkalosis
Answer: B
Rationale: The pH is low (acidemia). The HCO₃⁻ is low (< 22 mEq/L), indicating a
metabolic acidosis. The PaCO₂ is low (< 35 mmHg), indicating respiratory
compensation (hyperventilation to blow off CO₂ and raise the pH).
8. The nurse is preparing a patient for surgery. Which of the following is the
primary purpose of the preoperative "time-out" protocol?
A) To verify the patient's identity, the correct surgical site, and the correct
procedure before the incision.
NUR 170 – Complete Practice Test (2026) Questions and Answers with
100% Verified Correct Rationales | 2026 Updated | 100% correct
Detailed rationales are provided to reinforce clinical reasoning.
EXAM 1: Fluid & Electrolytes, Acid-Base Balances, and Perioperative Nursing
1. A patient is admitted with severe vomiting and diarrhea for 3 days. The nurse
suspects the patient is experiencing which type of fluid volume deficit?
A) Hypervolemia
B) Hypovolemia (isotonic dehydration)
C) Hypernatremia
D) Hyperkalemia
Answer: B
Rationale: Vomiting and diarrhea cause the loss of water and electrolytes in equal
proportions, leading to isotonic dehydration (hypovolemia). The body loses both
sodium and water, so the serum sodium remains normal, but total blood volume
drops.
2. The nurse is assessing a patient with severe dehydration. Which of the
following findings is a late sign of hypovolemic shock?
A) Tachycardia
B) Hypotension and decreased level of consciousness
C) Dry mucous membranes
D) Oliguria (decreased urine output)
Answer: B
Rationale: Tachycardia, dry mucous membranes, and oliguria are early
compensatory signs of hypovolemia. Hypotension and decreased level of
consciousness are late signs indicating that the body can no longer compensate,
and the patient is in decompensated shock.
, Page |2
3. The nurse is caring for a patient who has a nasogastric (NG) tube to low
intermittent suction. The patient is at highest risk for which electrolyte
imbalance?
A) Hyperkalemia
B) Hypokalemia (due to loss of gastric acids and potassium)
C) Hypercalcemia
D) Hyponatremia
Answer: B
Rationale: NG tube suction removes gastric juices, which are rich in hydrochloric
acid (HCl) and potassium. Prolonged suction leads to metabolic alkalosis (loss of
acid) and hypokalemia (loss of potassium).
4. A patient is prescribed 0.9% Normal Saline (NS) IV. The nurse understands
that this fluid is:
A) Hypotonic
B) Isotonic (expands intravascular volume without shifting fluid into cells)
C) Hypertonic
D) A colloid
Answer: B
Rationale: 0.9% Normal Saline has an osmolarity of 308 mOsm/L, which is close to
the normal serum osmolarity (275-295 mOsm/L). It is an isotonic fluid used to
expand the intravascular volume.
5. A patient's arterial blood gas (ABG) results show: pH 7.30, PaCO₂ 50 mmHg,
HCO₃⁻ 24 mEq/L. What is the acid-base disturbance?
A) Metabolic acidosis
B) Respiratory acidosis (the pH is low, PaCO₂ is high, and HCO₃⁻ is normal)
C) Metabolic alkalosis
D) Respiratory alkalosis
Answer: B
Rationale: The pH is low (acidemia). The PaCO₂ is high (> 45 mmHg), indicating a
, Page |3
respiratory cause. The HCO₃⁻ is normal (22-26 mEq/L). This is respiratory acidosis,
likely due to hypoventilation.
6. The nurse is caring for a patient with respiratory acidosis. Which of the
following nursing interventions is a priority?
A) Administer sodium bicarbonate IV.
B) Encourage the patient to breathe slowly.
C) Improve the patient's ventilation and airway clearance (e.g., reposition,
stimulate coughing, or prepare for mechanical ventilation).
D) Administer a sedative.
Answer: C
Rationale: Respiratory acidosis is caused by CO₂ retention due to hypoventilation.
The priority is to improve ventilation by repositioning the patient, encouraging
deep breathing, suctioning secretions, or preparing for mechanical ventilation.
7. A patient with diabetic ketoacidosis (DKA) presents with deep, rapid
respirations (Kussmaul respirations). The ABG shows pH 7.25, PaCO₂ 30 mmHg,
HCO₃⁻ 12 mEq/L. What is the acid-base disturbance?
A) Respiratory acidosis
B) Metabolic acidosis with respiratory compensation (the low HCO₃⁻ indicates
metabolic acidosis; the low PaCO₂ indicates the lungs are blowing off CO₂ to
compensate)
C) Metabolic alkalosis
D) Respiratory alkalosis
Answer: B
Rationale: The pH is low (acidemia). The HCO₃⁻ is low (< 22 mEq/L), indicating a
metabolic acidosis. The PaCO₂ is low (< 35 mmHg), indicating respiratory
compensation (hyperventilation to blow off CO₂ and raise the pH).
8. The nurse is preparing a patient for surgery. Which of the following is the
primary purpose of the preoperative "time-out" protocol?
A) To verify the patient's identity, the correct surgical site, and the correct
procedure before the incision.
