,NU 158 Medical-Surgical Nursing I
Exam Prep — Comprehensive Review +
Practice MCQs — Galen College of
Nursing 2025/2026
1. A patient has a serum potassium level of 6.8 mEq/L. Which ECG change is the nurse most likely to observe
first?
A. Flattened T waves and a prominent U wave
B. A widened QRS complex and prolonged PR interval
C. Tall, peaked (tented) T waves
D. ST-segment depression and T-wave inversion
Correct Answer: C
Rationale: Hyperkalemia (>5.0 mEq/L) causes a classic early ECG change of tall, peaked T waves. Flattened T
waves and U waves are associated with hypokalemia. Widened QRS and prolonged PR occur with severe
hyperkalemia but are not the earliest sign .
2. The nurse is caring for a patient with a serum sodium level of 118 mEq/L. Which clinical manifestation is the
priority to monitor?
A. Muscle twitching and tetany
B. Changes in level of consciousness
C. Polyuria and polydipsia
D. Bounding peripheral pulses
,Correct Answer: B
Rationale: Serum sodium of 118 mEq/L indicates severe hyponatremia, which can lead to cerebral edema and
increased intracranial pressure. The priority is monitoring neurological changes (confusion, lethargy, seizures,
coma). Muscle twitching is associated with hypocalcemia .
3. Which finding in a patient with heart failure is the most sensitive indicator of worsening fluid status?
A. Crackles auscultated in the lung bases
B. A 2-lb weight gain in 24 hours
C. Dyspnea on exertion
D. Presence of peripheral edema
Correct Answer: B
Rationale: Daily weight is the most sensitive and reliable indicator of fluid balance. A sudden weight gain of 2–
3 lbs in 24 hours reflects fluid accumulation before physical signs like crackles, dyspnea, or edema become
apparent (1 L of fluid weighs approximately 2.2 lbs) .
4. An IV bolus of 0.9% normal saline is prescribed for a patient with hypovolemia. Which assessment finding
indicates fluid resuscitation is effective?
A. Heart rate decreases from 110 to 80 beats/min
B. Blood pressure decreases from 140/90 to 110/70 mmHg
C. Urine output decreases from 60 to 30 mL/hr
D. The patient reports feeling more thirsty
, Correct Answer: A
Rationale: In hypovolemia, tachycardia is a compensatory mechanism. A decrease in heart rate toward normal
is a key indicator that intravascular volume is being restored. Decreased BP, decreased urine output, or
increased thirst indicate worsening condition .
5. The nurse is caring for a patient with a magnesium level of 1.0 mEq/L. Which assessment finding is most
consistent with this electrolyte imbalance?
A. Hypotension and bradycardia
B. Hyperactive deep tendon reflexes
C. Muscle weakness and lethargy
D. Prolonged QT interval on ECG
Correct Answer: B
Rationale: Magnesium 1.0 mEq/L indicates hypomagnesemia. This condition increases neuromuscular
irritability, leading to hyperactive deep tendon reflexes, tremors, and positive Chvostek's sign. Hypotension,
bradycardia, muscle weakness, and lethargy are signs of hypermagnesemia .
6. A patient is admitted with severe diarrhea and vomiting for three days. Which acid-base imbalance is the
patient most at risk for developing?
A. Metabolic alkalosis
B. Metabolic acidosis
C. Respiratory acidosis
D. Respiratory alkalosis
Exam Prep — Comprehensive Review +
Practice MCQs — Galen College of
Nursing 2025/2026
1. A patient has a serum potassium level of 6.8 mEq/L. Which ECG change is the nurse most likely to observe
first?
A. Flattened T waves and a prominent U wave
B. A widened QRS complex and prolonged PR interval
C. Tall, peaked (tented) T waves
D. ST-segment depression and T-wave inversion
Correct Answer: C
Rationale: Hyperkalemia (>5.0 mEq/L) causes a classic early ECG change of tall, peaked T waves. Flattened T
waves and U waves are associated with hypokalemia. Widened QRS and prolonged PR occur with severe
hyperkalemia but are not the earliest sign .
2. The nurse is caring for a patient with a serum sodium level of 118 mEq/L. Which clinical manifestation is the
priority to monitor?
A. Muscle twitching and tetany
B. Changes in level of consciousness
C. Polyuria and polydipsia
D. Bounding peripheral pulses
,Correct Answer: B
Rationale: Serum sodium of 118 mEq/L indicates severe hyponatremia, which can lead to cerebral edema and
increased intracranial pressure. The priority is monitoring neurological changes (confusion, lethargy, seizures,
coma). Muscle twitching is associated with hypocalcemia .
3. Which finding in a patient with heart failure is the most sensitive indicator of worsening fluid status?
A. Crackles auscultated in the lung bases
B. A 2-lb weight gain in 24 hours
C. Dyspnea on exertion
D. Presence of peripheral edema
Correct Answer: B
Rationale: Daily weight is the most sensitive and reliable indicator of fluid balance. A sudden weight gain of 2–
3 lbs in 24 hours reflects fluid accumulation before physical signs like crackles, dyspnea, or edema become
apparent (1 L of fluid weighs approximately 2.2 lbs) .
4. An IV bolus of 0.9% normal saline is prescribed for a patient with hypovolemia. Which assessment finding
indicates fluid resuscitation is effective?
A. Heart rate decreases from 110 to 80 beats/min
B. Blood pressure decreases from 140/90 to 110/70 mmHg
C. Urine output decreases from 60 to 30 mL/hr
D. The patient reports feeling more thirsty
, Correct Answer: A
Rationale: In hypovolemia, tachycardia is a compensatory mechanism. A decrease in heart rate toward normal
is a key indicator that intravascular volume is being restored. Decreased BP, decreased urine output, or
increased thirst indicate worsening condition .
5. The nurse is caring for a patient with a magnesium level of 1.0 mEq/L. Which assessment finding is most
consistent with this electrolyte imbalance?
A. Hypotension and bradycardia
B. Hyperactive deep tendon reflexes
C. Muscle weakness and lethargy
D. Prolonged QT interval on ECG
Correct Answer: B
Rationale: Magnesium 1.0 mEq/L indicates hypomagnesemia. This condition increases neuromuscular
irritability, leading to hyperactive deep tendon reflexes, tremors, and positive Chvostek's sign. Hypotension,
bradycardia, muscle weakness, and lethargy are signs of hypermagnesemia .
6. A patient is admitted with severe diarrhea and vomiting for three days. Which acid-base imbalance is the
patient most at risk for developing?
A. Metabolic alkalosis
B. Metabolic acidosis
C. Respiratory acidosis
D. Respiratory alkalosis
