RASMUSSEN NUR2502 MDC III EXAM
1: 220 Practice Questions with
Complete Rationales & Answer Key
(Newest 2026 Update)/Instant
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Section 1: Fluid, Electrolyte & Acid-Base Balance (Questions 1-30)
1. A patient has a serum sodium level of 155 mEq/L. Which IV fluid
would the nurse expect to be prescribed?
A) 0.9% normal saline
B) 0.45% normal saline (half-normal saline)
C) 3% normal saline
D) D5W
Correct Answer: B
Rationale: Hypernatremia (>145 mEq/L) indicates water deficit or sodium
excess. Hypotonic fluid (0.45% NS) provides free water to dilute serum
sodium. 3% NS is hypertonic and used only for severe hyponatremia. 0.9%
NS would worsen hypernatremia.
,2. A patient with heart failure has a serum potassium of 2.9 mEq/L.
Which EKG change should the nurse anticipate?
A) Peaked T waves
B) U waves
C) Wide QRS complex
D) Absent P waves
Correct Answer: B
Rationale: Hypokalemia (<3.5 mEq/L) causes flattened T waves, prominent
U waves, and ST depression. Peaked T waves indicate hyperkalemia. Wide
QRS complex occurs with severe hyperkalemia or certain dysrhythmias.
3. The nurse is caring for a patient with a potassium level of 7.0 mEq/L.
Which intervention should the nurse implement first?
A) Administer sodium polystyrene sulfonate (Kayexalate)
B) Prepare for hemodialysis
C) Administer IV calcium gluconate
D) Give IV insulin and dextrose
Correct Answer: C
Rationale: Severe hyperkalemia (>6.5 mEq/L) requires cardiac membrane
stabilization with IV calcium gluconate first to prevent life-threatening
arrhythmias. Then insulin with dextrose shifts K⁺ into cells, Kayexalate
removes K⁺ via the GI tract, and dialysis is the definitive treatment.
,4. A patient presents with muscle twitching, a positive Chvostek's sign,
and a prolonged QT interval on EKG. Which electrolyte imbalance is
most likely?
A) Hypercalcemia
B) Hypocalcemia
C) Hypermagnesemia
D) Hyperkalemia
Correct Answer: B
Rationale: Hypocalcemia causes neuromuscular irritability (muscle
twitching, positive Chvostek's and Trousseau's signs) and a prolonged QT
interval. Hypercalcemia shortens the QT interval. Hypermagnesemia causes
hyporeflexia and sedation.
5. A patient with a nasogastric tube to continuous suction is at risk for
which acid-base disorder?
A) Metabolic acidosis
B) Metabolic alkalosis
C) Respiratory acidosis
D) Respiratory alkalosis
Correct Answer: B
Rationale: NG suction removes gastric acid (HCl). Loss of hydrogen ions
leads to metabolic alkalosis (increased HCO₃⁻, increased pH).
, 6. Which EKG finding is characteristic of hypercalcemia?
A) Shortened QT interval
B) Prolonged QT interval
C) Peaked T waves
D) U waves
Correct Answer: A
Rationale: Hypercalcemia shortens the QT interval by speeding
repolarization. Hypocalcemia prolongs the QT interval. U waves indicate
hypokalemia. Peaked T waves indicate hyperkalemia.
7. A patient has a magnesium level of 0.9 mg/dL (normal 1.5-2.5).
Which assessment finding correlates?
A) Hyperreflexia and muscle tremors
B) Hyporeflexia and lethargy
C) Flaccid paralysis
D) Respiratory depression
Correct Answer: A
Rationale: Hypomagnesemia (<1.5 mg/dL) causes neuromuscular
irritability (tremors, hyperreflexia, seizures, torsades de pointes).
Hypermagnesemia causes hyporeflexia, sedation, and respiratory
depression.
1: 220 Practice Questions with
Complete Rationales & Answer Key
(Newest 2026 Update)/Instant
Download PDF
Section 1: Fluid, Electrolyte & Acid-Base Balance (Questions 1-30)
1. A patient has a serum sodium level of 155 mEq/L. Which IV fluid
would the nurse expect to be prescribed?
A) 0.9% normal saline
B) 0.45% normal saline (half-normal saline)
C) 3% normal saline
D) D5W
Correct Answer: B
Rationale: Hypernatremia (>145 mEq/L) indicates water deficit or sodium
excess. Hypotonic fluid (0.45% NS) provides free water to dilute serum
sodium. 3% NS is hypertonic and used only for severe hyponatremia. 0.9%
NS would worsen hypernatremia.
,2. A patient with heart failure has a serum potassium of 2.9 mEq/L.
Which EKG change should the nurse anticipate?
A) Peaked T waves
B) U waves
C) Wide QRS complex
D) Absent P waves
Correct Answer: B
Rationale: Hypokalemia (<3.5 mEq/L) causes flattened T waves, prominent
U waves, and ST depression. Peaked T waves indicate hyperkalemia. Wide
QRS complex occurs with severe hyperkalemia or certain dysrhythmias.
3. The nurse is caring for a patient with a potassium level of 7.0 mEq/L.
Which intervention should the nurse implement first?
A) Administer sodium polystyrene sulfonate (Kayexalate)
B) Prepare for hemodialysis
C) Administer IV calcium gluconate
D) Give IV insulin and dextrose
Correct Answer: C
Rationale: Severe hyperkalemia (>6.5 mEq/L) requires cardiac membrane
stabilization with IV calcium gluconate first to prevent life-threatening
arrhythmias. Then insulin with dextrose shifts K⁺ into cells, Kayexalate
removes K⁺ via the GI tract, and dialysis is the definitive treatment.
,4. A patient presents with muscle twitching, a positive Chvostek's sign,
and a prolonged QT interval on EKG. Which electrolyte imbalance is
most likely?
A) Hypercalcemia
B) Hypocalcemia
C) Hypermagnesemia
D) Hyperkalemia
Correct Answer: B
Rationale: Hypocalcemia causes neuromuscular irritability (muscle
twitching, positive Chvostek's and Trousseau's signs) and a prolonged QT
interval. Hypercalcemia shortens the QT interval. Hypermagnesemia causes
hyporeflexia and sedation.
5. A patient with a nasogastric tube to continuous suction is at risk for
which acid-base disorder?
A) Metabolic acidosis
B) Metabolic alkalosis
C) Respiratory acidosis
D) Respiratory alkalosis
Correct Answer: B
Rationale: NG suction removes gastric acid (HCl). Loss of hydrogen ions
leads to metabolic alkalosis (increased HCO₃⁻, increased pH).
, 6. Which EKG finding is characteristic of hypercalcemia?
A) Shortened QT interval
B) Prolonged QT interval
C) Peaked T waves
D) U waves
Correct Answer: A
Rationale: Hypercalcemia shortens the QT interval by speeding
repolarization. Hypocalcemia prolongs the QT interval. U waves indicate
hypokalemia. Peaked T waves indicate hyperkalemia.
7. A patient has a magnesium level of 0.9 mg/dL (normal 1.5-2.5).
Which assessment finding correlates?
A) Hyperreflexia and muscle tremors
B) Hyporeflexia and lethargy
C) Flaccid paralysis
D) Respiratory depression
Correct Answer: A
Rationale: Hypomagnesemia (<1.5 mg/dL) causes neuromuscular
irritability (tremors, hyperreflexia, seizures, torsades de pointes).
Hypermagnesemia causes hyporeflexia, sedation, and respiratory
depression.
