© 2026/27 Qs & Ans
Fluid and Electrolyte Balance Assessment
Questions And 100% Correct Answers With
Verified Rationales | Instant Pdf Download
1. Which electrolyte is the major extracellular cation?
A. Potassium
B. Sodium
C. Calcium
D. Magnesium
Answer: B. Sodium
Rationale: Sodium is the primary extracellular cation responsible for fluid
balance and osmotic pressure.
2. Which electrolyte is the major intracellular cation?
A. Sodium
B. Calcium
C. Potassium
D. Chloride
Answer: C. Potassium
Rationale: Potassium is primarily found inside cells and is critical for
cardiac and muscle function.
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, © 2026/27 Qs & Ans
3. Which assessment finding suggests fluid volume excess?
A. Crackles in lungs
B. Dry mucous membranes
C. Hypotension
D. Tachycardia only
Answer: A. Crackles in lungs
Rationale: Fluid overload leads to pulmonary congestion and crackles.
4. Which symptom is most consistent with dehydration?
A. Dry mucous membranes
B. Edema
C. Hypertension
D. Bounding pulse
Answer: A. Dry mucous membranes
Rationale: Fluid loss reduces tissue hydration.
5. Which vital sign change is expected in hypovolemia?
A. Tachycardia
B. Bradycardia
C. Hypertension
D. Increased urine output
Answer: A. Tachycardia
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, © 2026/27 Qs & Ans
Rationale: Heart rate increases to compensate for low circulating volume.
6. Which lab value indicates dehydration?
A. Elevated hematocrit
B. Low sodium
C. Low potassium
D. Low hemoglobin only
Answer: A. Elevated hematocrit
Rationale: Plasma volume decreases, concentrating red blood cells.
7. Which fluid is isotonic?
A. 0.9% Normal Saline
B. 0.45% Normal Saline
C. D5W after metabolism
D. Sterile water
Answer: A. 0.9% Normal Saline
Rationale: Isotonic fluids have equal osmolarity to plasma.
8. Which fluid is hypotonic?
A. 0.45% Normal Saline
B. 0.9% Normal Saline
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, © 2026/27 Qs & Ans
C. Lactated Ringer’s
D. D5NS
Answer: A. 0.45% Normal Saline
Rationale: Hypotonic solutions shift fluid into cells.
9. Which fluid is hypertonic?
A. 3% Normal Saline
B. 0.9% Normal Saline
C. D5W
D. Sterile water
Answer: A. 3% Normal Saline
Rationale: Hypertonic solutions draw fluid into vascular space.
10. Which electrolyte imbalance is life-threatening in cardiac patients?
A. Hyperkalemia
B. Hypernatremia
C. Hypercalcemia
D. Hypomagnesemia only
Answer: A. Hyperkalemia
Rationale: Can cause fatal cardiac arrhythmias.
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Fluid and Electrolyte Balance Assessment
Questions And 100% Correct Answers With
Verified Rationales | Instant Pdf Download
1. Which electrolyte is the major extracellular cation?
A. Potassium
B. Sodium
C. Calcium
D. Magnesium
Answer: B. Sodium
Rationale: Sodium is the primary extracellular cation responsible for fluid
balance and osmotic pressure.
2. Which electrolyte is the major intracellular cation?
A. Sodium
B. Calcium
C. Potassium
D. Chloride
Answer: C. Potassium
Rationale: Potassium is primarily found inside cells and is critical for
cardiac and muscle function.
1
, © 2026/27 Qs & Ans
3. Which assessment finding suggests fluid volume excess?
A. Crackles in lungs
B. Dry mucous membranes
C. Hypotension
D. Tachycardia only
Answer: A. Crackles in lungs
Rationale: Fluid overload leads to pulmonary congestion and crackles.
4. Which symptom is most consistent with dehydration?
A. Dry mucous membranes
B. Edema
C. Hypertension
D. Bounding pulse
Answer: A. Dry mucous membranes
Rationale: Fluid loss reduces tissue hydration.
5. Which vital sign change is expected in hypovolemia?
A. Tachycardia
B. Bradycardia
C. Hypertension
D. Increased urine output
Answer: A. Tachycardia
2
, © 2026/27 Qs & Ans
Rationale: Heart rate increases to compensate for low circulating volume.
6. Which lab value indicates dehydration?
A. Elevated hematocrit
B. Low sodium
C. Low potassium
D. Low hemoglobin only
Answer: A. Elevated hematocrit
Rationale: Plasma volume decreases, concentrating red blood cells.
7. Which fluid is isotonic?
A. 0.9% Normal Saline
B. 0.45% Normal Saline
C. D5W after metabolism
D. Sterile water
Answer: A. 0.9% Normal Saline
Rationale: Isotonic fluids have equal osmolarity to plasma.
8. Which fluid is hypotonic?
A. 0.45% Normal Saline
B. 0.9% Normal Saline
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, © 2026/27 Qs & Ans
C. Lactated Ringer’s
D. D5NS
Answer: A. 0.45% Normal Saline
Rationale: Hypotonic solutions shift fluid into cells.
9. Which fluid is hypertonic?
A. 3% Normal Saline
B. 0.9% Normal Saline
C. D5W
D. Sterile water
Answer: A. 3% Normal Saline
Rationale: Hypertonic solutions draw fluid into vascular space.
10. Which electrolyte imbalance is life-threatening in cardiac patients?
A. Hyperkalemia
B. Hypernatremia
C. Hypercalcemia
D. Hypomagnesemia only
Answer: A. Hyperkalemia
Rationale: Can cause fatal cardiac arrhythmias.
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