Chapter 42 Fluid, Electrolyte, and Acid-Base Balance Fundamentals of Nursing 11th Edition (Potter & Perry) 50 NCLEX-Style Exam Questions with Detailed Rationale

1. A patient with severe vomiting is at risk for which acid-base imbalance? A. Respiratory acidosis B. Respiratory alkalosis C. Metabolic alkalosis D. Metabolic acidosis Correct Answer: C Rationale: Vomiting leads to the loss of hydrochloric acid from the stomach, causing a metabolic alkalosis. ________________________________________ 2. Which electrolyte imbalance is most likely to cause cardiac dysrhythmias? A. Hypernatremia B. Hypokalemia C. Hypocalcemia D. Hypermagnesemia Correct Answer: B Rationale: Potassium plays a vital role in cardiac conduction. Low potassium levels (hypokalemia) can result in dysrhythmias. ________________________________________ 3. A patient with heart failure is receiving IV 0.9% sodium chloride at 125 mL/hr. Which assessment requires immediate action? A. BP 118/76 mm Hg B. Urine output 30 mL/hr C. Crackles in bilateral lung bases D. Skin turgor normal Correct Answer: C Rationale: Crackles indicate fluid volume overload and pulmonary edema, requiring immediate nursing intervention. ________________________________________ 4. A patient has a serum sodium level of 127 mEq/L. Which clinical manifestation is most likely? A. Constipation B. Abdominal pain C. Confusion and lethargy D. Muscle cramping Correct Answer: C Rationale: Hyponatremia often affects neurological function, resulting in confusion, lethargy, and potentially seizures. ________________________________________ 5. Which patient is at highest risk for developing dehydration? A. A 60-year-old on a low-sodium diet B. A 45-year-old with a BMI of 30 C. An 85-year-old with dementia D. A 30-year-old marathon runner Correct Answer: C Rationale: Older adults with cognitive impairment may not recognize or communicate thirst, increasing dehydration risk. ________________________________________ 6. The nurse suspects fluid volume deficit. Which finding supports this suspicion? A. Full, bounding pulses B. Neck vein distention C. Postural hypotension D. Weight gain overnight Correct Answer: C Rationale: A hallmark of fluid volume deficit is orthostatic hypotension due to decreased circulating blood volume. ________________________________________ 7. Which fluid should the nurse expect to administer for a patient with hyponatremia due to fluid overload? A. 0.9% sodium chloride B. 3% sodium chloride C. D5W D. Lactated Ringer’s solution Correct Answer: B Rationale: Hypertonic saline (3% NaCl) is used cautiously to correct severe hyponatremia and reduce cerebral edema. ________________________________________ 8. Which sign indicates hypocalcemia? A. Negative Chvostek’s sign B. Bradycardia C. Muscle twitching D. Hypoactive reflexes Correct Answer: C Rationale: Hypocalcemia increases neuromuscular excitability, causing muscle twitching, cramps, and positive Chvostek’s sign. ________________________________________ 9. A patient with prolonged diarrhea is likely to develop which acid-base imbalance? A. Respiratory alkalosis B. Metabolic alkalosis C. Metabolic acidosis D. Respiratory acidosis Correct Answer: C Rationale: Diarrhea causes loss of bicarbonate from the intestines, leading to metabolic acidosis.