NACE Fluid and Electrolyte Balance 1 — Questions and Answers
Question 1: A patient's serum sodium is 128 mEq/L. Which symptom would the nurse most likely assess?
- Muscle cramps and irritability (Correct answer)
- Extreme thirst and dry mucous membranes
- Decreased deep tendon reflexes and bradycardia
- Hypertension and flushed skin
Correct answer: Muscle cramps and irritability
Hyponatremia (sodium <135 mEq/L) causes neurological symptoms including confusion, headache, muscle cramps, and irritability due to osmotic fluid shifts into brain cells.
Question 2: Which IV solution is classified as isotonic?
- 0.45% sodium chloride
- 0.9% sodium chloride (Correct answer)
- 3% sodium chloride
- 5% dextrose in 0.45% sodium chloride
Correct answer: 0.9% sodium chloride
0.9% sodium chloride (normal saline) is isotonic with an osmolality of approximately 308 mOsm/L, close to plasma osmolality, so it does not cause fluid shifts into or out of cells.
Question 3: A patient with chronic renal failure has a serum potassium of 6.2 mEq/L. Which ECG change would the nurse anticipate first?
- Prolonged PR interval only
- Peaked T waves (Correct answer)
- Flattened T waves with prominent U waves
- ST-segment depression
Correct answer: Peaked T waves
Hyperkalemia initially produces tall, narrow (peaked) T waves on ECG due to altered cardiac repolarization; this may progress to widened QRS complexes and ventricular fibrillation.
Question 4: A postoperative patient receiving 3 L of IV fluids daily develops a new respiratory finding. Which assessment finding indicates fluid overload?
- Urine output of 50 mL/hr
- Blood pressure 88/60 mmHg
- Bilateral crackles at the lung bases (Correct answer)
- Serum sodium 138 mEq/L
Correct answer: Bilateral crackles at the lung bases
Bilateral crackles at the lung bases indicate pulmonary edema from fluid overload, as excess fluid accumulates in the alveoli and interstitial lung tissue.
Question 5: Which clinical finding is most consistent with severe dehydration in an adult patient?
- Bradycardia and hypertension
- Bounding pulse and jugular vein distension
- Poor skin turgor and concentrated urine (Correct answer)
- Peripheral edema and ascites
Correct answer: Poor skin turgor and concentrated urine
Poor skin turgor (tenting) and dark, concentrated urine (high specific gravity) are classic signs of severe dehydration reflecting significant fluid deficit.
Question 6: A patient's serum potassium is 2.9 mEq/L. Which intervention is the priority nursing action?
- Administer IV potassium chloride via rapid IV push
- Place the patient on continuous cardiac monitoring (Correct answer)
- Restrict dietary potassium intake
- Administer sodium polystyrene sulfonate (Kayexalate)
Correct answer: Place the patient on continuous cardiac monitoring
Hypokalemia can cause life-threatening dysrhythmias; continuous cardiac monitoring is the priority to detect and respond to arrhythmias early before or during potassium replacement.
Question 7: Which patient is at greatest risk for developing hypernatremia?
- A 70-year-old with advanced dementia who cannot request fluids independently (Correct answer)
- A 45-year-old receiving furosemide therapy for heart failure
- A 30-year-old diagnosed with SIADH
- A 60-year-old with fluid overload from cirrhosis
Correct answer: A 70-year-old with advanced dementia who cannot request fluids independently
Patients with dementia who cannot communicate thirst or independently access water are at high risk for hypernatremia due to inadequate free water intake relative to sodium.
NACE Fluid and Electrolyte Balance 1
A patient's serum sodium is 128 mEq/L.
Which symptom would the nurse most likely assess?