MEDICAL-SURGICAL NURSING: FLUID &
ELECTROLYTES — 2026/2027 | 75 QUESTIONS AND
CORRECT ANSWERS | GRADED A+ | 100% VERIFIED
Medical-Surgical Nursing Fluid & Electrolyte Balance Examination | Core Domains: Sodium,
Potassium, Calcium, Magnesium, Phosphorus Imbalances, Fluid Volume Deficit/Excess, Third-Spacing,
IV Fluid Types, Acid-Base Balance, ABG Interpretation, and Nursing Interventions.
Exam Structure
Medical-Surgical Nursing Fluid & Electrolyte Examination is commonly structured as follows:
75 multiple-choice questions
Single-best-answer format
Application-, analysis-, and clinical judgment–focused items
Integrated case-based scenarios with electrolyte imbalance presentations
Questions incorporating NCLEX-style priority, safety, and medication administration frameworks
ABG interpretation questions
ECG rhythm identification related to electrolyte imbalances
Pharmacology questions specific to electrolyte replacement and management
Introduction
This Medical-Surgical Nursing Fluid & Electrolytes examination preparation resource for the 2026/2027
academic cycle reflects undergraduate nursing curriculum standards emphasizing comprehensive
understanding of fluid, electrolyte, and acid-base balance. Fluid and electrolyte imbalances are among
the most common clinical problems encountered in medical-surgical nursing practice, affecting virtually
every body system and requiring astute assessment, critical thinking, and prompt intervention.
Answer Format
All questions must be presented in bold text for clear distinction and readability.
All correct answers must be presented in bold and lime green, followed by clearly defined, clinically
focused rationales in italic format that reinforce fluid and electrolyte principles, pathophysiology,
nursing assessments, evidence-based interventions, pharmacological reasoning, and clinical judgment
required for optimal patient outcomes.
,Section A: Potassium Imbalances (Hypokalemia & Hyperkalemia)
1. A patient with heart failure has been receiving furosemide (Lasix) 40 mg IV twice
daily. The patient reports weakness and muscle cramps. Vital signs: BP 110/70, HR
102 and irregular, RR 18, O2 saturation 95%. Which laboratory value should the
nurse assess first?
A. Serum sodium
B. Serum potassium
C. Serum calcium
D. Serum magnesium
Correct Answer: B
Rationale: Loop diuretics such as furosemide cause significant potassium loss, leading to
hypokalemia. The patient's symptoms of weakness, muscle cramps, and irregular heart rate are
classic manifestations of hypokalemia. Hypokalemia increases the risk of life-threatening
dysrhythmias, particularly in patients with underlying cardiac conditions.
2. A patient with chronic kidney disease presents with muscle weakness, peaked T
waves on ECG, and a heart rate of 48 bpm. Which medication should the nurse
prepare to administer first?
A. Sodium polystyrene sulfonate (Kayexalate)
B. Regular insulin and dextrose 50%
C. Calcium gluconate
D. Sodium bicarbonate
Correct Answer: C
Rationale: The patient's symptoms and ECG findings indicate severe hyperkalemia. Calcium
gluconate should be administered first to stabilize the cardiac membrane and prevent life-
threatening dysrhythmias. While Kayexalate, insulin/dextrose, and sodium bicarbonate all help
lower serum potassium, they do not provide immediate cardiac protection. Calcium gluconate
works within minutes to antagonize the cardiac effects of hyperkalemia, making it the priority
intervention.
3. The nurse is caring for a patient receiving IV furosemide and digoxin. Which
electrolyte imbalance increases the patient's risk for digoxin toxicity?
A. Hyponatremia
B. Hypokalemia
C. Hypercalcemia
D. Hypomagnesemia
, Correct Answer: B
Rationale: Hypokalemia potentiates the effects of digoxin by increasing the binding of digoxin to
the sodium-potassium ATPase pump, leading to digoxin toxicity even at therapeutic serum levels.
Furosemide causes potassium loss, placing the patient at risk. Signs of digoxin toxicity include
nausea, vomiting, visual disturbances (yellow-green halos), and dysrhythmias.
4. A patient with renal failure has a serum potassium of 6.8 mEq/L. The nurse
administers intravenous insulin and dextrose. Which best describes the mechanism of
action for this intervention?
A. Insulin binds to potassium, neutralizing its cardiac effects.
B. Insulin and dextrose promote potassium excretion through the kidneys.
C. Insulin drives potassium into cells along with glucose.
D. Dextrose dilutes serum potassium concentration.
Correct Answer: C
Rationale: Insulin promotes cellular uptake of glucose and simultaneously drives potassium into
cells via stimulation of the sodium-potassium ATPase pump. This temporarily shifts potassium from
extracellular to intracellular compartments, lowering serum potassium levels. This is a temporary
measure while awaiting more definitive treatment such as Kayexalate or dialysis.
5. Which ECG change is characteristic of hypokalemia?
A. Peaked T waves
B. Prolonged PR interval
C. U waves
D. Widened QRS complex
Correct Answer: C
Rationale: Hypokalemia classically presents with U waves (extra deflection after the T wave), ST
depression, and flattened T waves. Peaked T waves are characteristic of hyperkalemia. Prolonged
PR interval and widened QRS complex can occur with various electrolyte imbalances but are not
specific to hypokalemia. U waves are the hallmark ECG finding of hypokalemia.
6. A patient receiving hydrochlorothiazide for hypertension reports fatigue, weakness,
and constipation. Vital signs are stable. Which laboratory value would the nurse
expect to be decreased?
A. Sodium
B. Potassium
C. Calcium
ELECTROLYTES — 2026/2027 | 75 QUESTIONS AND
CORRECT ANSWERS | GRADED A+ | 100% VERIFIED
Medical-Surgical Nursing Fluid & Electrolyte Balance Examination | Core Domains: Sodium,
Potassium, Calcium, Magnesium, Phosphorus Imbalances, Fluid Volume Deficit/Excess, Third-Spacing,
IV Fluid Types, Acid-Base Balance, ABG Interpretation, and Nursing Interventions.
Exam Structure
Medical-Surgical Nursing Fluid & Electrolyte Examination is commonly structured as follows:
75 multiple-choice questions
Single-best-answer format
Application-, analysis-, and clinical judgment–focused items
Integrated case-based scenarios with electrolyte imbalance presentations
Questions incorporating NCLEX-style priority, safety, and medication administration frameworks
ABG interpretation questions
ECG rhythm identification related to electrolyte imbalances
Pharmacology questions specific to electrolyte replacement and management
Introduction
This Medical-Surgical Nursing Fluid & Electrolytes examination preparation resource for the 2026/2027
academic cycle reflects undergraduate nursing curriculum standards emphasizing comprehensive
understanding of fluid, electrolyte, and acid-base balance. Fluid and electrolyte imbalances are among
the most common clinical problems encountered in medical-surgical nursing practice, affecting virtually
every body system and requiring astute assessment, critical thinking, and prompt intervention.
Answer Format
All questions must be presented in bold text for clear distinction and readability.
All correct answers must be presented in bold and lime green, followed by clearly defined, clinically
focused rationales in italic format that reinforce fluid and electrolyte principles, pathophysiology,
nursing assessments, evidence-based interventions, pharmacological reasoning, and clinical judgment
required for optimal patient outcomes.
,Section A: Potassium Imbalances (Hypokalemia & Hyperkalemia)
1. A patient with heart failure has been receiving furosemide (Lasix) 40 mg IV twice
daily. The patient reports weakness and muscle cramps. Vital signs: BP 110/70, HR
102 and irregular, RR 18, O2 saturation 95%. Which laboratory value should the
nurse assess first?
A. Serum sodium
B. Serum potassium
C. Serum calcium
D. Serum magnesium
Correct Answer: B
Rationale: Loop diuretics such as furosemide cause significant potassium loss, leading to
hypokalemia. The patient's symptoms of weakness, muscle cramps, and irregular heart rate are
classic manifestations of hypokalemia. Hypokalemia increases the risk of life-threatening
dysrhythmias, particularly in patients with underlying cardiac conditions.
2. A patient with chronic kidney disease presents with muscle weakness, peaked T
waves on ECG, and a heart rate of 48 bpm. Which medication should the nurse
prepare to administer first?
A. Sodium polystyrene sulfonate (Kayexalate)
B. Regular insulin and dextrose 50%
C. Calcium gluconate
D. Sodium bicarbonate
Correct Answer: C
Rationale: The patient's symptoms and ECG findings indicate severe hyperkalemia. Calcium
gluconate should be administered first to stabilize the cardiac membrane and prevent life-
threatening dysrhythmias. While Kayexalate, insulin/dextrose, and sodium bicarbonate all help
lower serum potassium, they do not provide immediate cardiac protection. Calcium gluconate
works within minutes to antagonize the cardiac effects of hyperkalemia, making it the priority
intervention.
3. The nurse is caring for a patient receiving IV furosemide and digoxin. Which
electrolyte imbalance increases the patient's risk for digoxin toxicity?
A. Hyponatremia
B. Hypokalemia
C. Hypercalcemia
D. Hypomagnesemia
, Correct Answer: B
Rationale: Hypokalemia potentiates the effects of digoxin by increasing the binding of digoxin to
the sodium-potassium ATPase pump, leading to digoxin toxicity even at therapeutic serum levels.
Furosemide causes potassium loss, placing the patient at risk. Signs of digoxin toxicity include
nausea, vomiting, visual disturbances (yellow-green halos), and dysrhythmias.
4. A patient with renal failure has a serum potassium of 6.8 mEq/L. The nurse
administers intravenous insulin and dextrose. Which best describes the mechanism of
action for this intervention?
A. Insulin binds to potassium, neutralizing its cardiac effects.
B. Insulin and dextrose promote potassium excretion through the kidneys.
C. Insulin drives potassium into cells along with glucose.
D. Dextrose dilutes serum potassium concentration.
Correct Answer: C
Rationale: Insulin promotes cellular uptake of glucose and simultaneously drives potassium into
cells via stimulation of the sodium-potassium ATPase pump. This temporarily shifts potassium from
extracellular to intracellular compartments, lowering serum potassium levels. This is a temporary
measure while awaiting more definitive treatment such as Kayexalate or dialysis.
5. Which ECG change is characteristic of hypokalemia?
A. Peaked T waves
B. Prolonged PR interval
C. U waves
D. Widened QRS complex
Correct Answer: C
Rationale: Hypokalemia classically presents with U waves (extra deflection after the T wave), ST
depression, and flattened T waves. Peaked T waves are characteristic of hyperkalemia. Prolonged
PR interval and widened QRS complex can occur with various electrolyte imbalances but are not
specific to hypokalemia. U waves are the hallmark ECG finding of hypokalemia.
6. A patient receiving hydrochlorothiazide for hypertension reports fatigue, weakness,
and constipation. Vital signs are stable. Which laboratory value would the nurse
expect to be decreased?
A. Sodium
B. Potassium
C. Calcium
