NACE Fluid and Electrolyte Balance 5 — Questions and Answers
Question 1: A client taking furosemide reports muscle cramps and weakness. The nurse checks the lab results and finds a serum potassium of 3.1 mEq/L. Which action is the priority?
- Administer the next furosemide dose as scheduled
- Hold the furosemide and notify the provider (Correct answer)
- Encourage the client to eat more protein
- Document and reassess in 4 hours
Correct answer: Hold the furosemide and notify the provider
Hypokalemia (K+ < 3.5 mEq/L) with symptoms requires holding a potassium-wasting diuretic and notifying the provider to prevent life-threatening dysrhythmias.
Question 2: Which arterial blood gas result indicates metabolic alkalosis with respiratory compensation?
- pH 7.28, PaCO2 30, HCO3 14
- pH 7.50, PaCO2 48, HCO3 36 (Correct answer)
- pH 7.32, PaCO2 55, HCO3 28
- pH 7.48, PaCO2 30, HCO3 22
Correct answer: pH 7.50, PaCO2 48, HCO3 36
pH 7.50 (alkalotic), elevated HCO3 36 (metabolic cause), and elevated PaCO2 48 (respiratory compensation by retaining CO2) indicate compensated metabolic alkalosis.
Question 3: A client presents with confusion, muscle twitching, and a serum sodium of 122 mEq/L. What is the most likely cause of these neurological symptoms?
- Cells shrinking due to hyperosmolar state
- Cerebral edema from hypotonic fluid shifting into brain cells (Correct answer)
- Increased ADH suppression
- Hyperchloremia-induced nerve conduction changes
Correct answer: Cerebral edema from hypotonic fluid shifting into brain cells
Severe hyponatremia causes water to shift into brain cells, leading to cerebral edema and neurological symptoms such as confusion and seizures.
Question 4: Which client is at greatest risk for developing hypermagnesemia?
- A 25-year-old with Crohn's disease on TPN
- A 70-year-old with chronic kidney disease taking magnesium-containing antacids (Correct answer)
- A postpartum client receiving oxytocin
- A client with nasogastric suction for 3 days
Correct answer: A 70-year-old with chronic kidney disease taking magnesium-containing antacids
Impaired renal excretion combined with magnesium intake from antacids places clients with chronic kidney disease at highest risk for hypermagnesemia.
Question 5: The nurse assesses a client and notes weak, irregular pulse, flat T waves on ECG, and abdominal distension. Which electrolyte imbalance is most likely?
- Hyperkalemia
- Hypomagnesemia
- Hypokalemia (Correct answer)
- Hypercalcemia
Correct answer: Hypokalemia
Flat or inverted T waves, U waves, weak pulse, and decreased GI motility (distension) are classic ECG and clinical signs of hypokalemia.
Question 6: A client is prescribed 3% hypertonic saline for severe hyponatremia. Which complication should the nurse monitor for during infusion?
- Hypoglycemia
- Osmotic demyelination syndrome if corrected too rapidly (Correct answer)
- Acute respiratory alkalosis
- Hyperkalemia
Correct answer: Osmotic demyelination syndrome if corrected too rapidly
Correcting chronic hyponatremia too quickly with hypertonic saline can cause osmotic demyelination syndrome (central pontine myelinolysis), a severe neurological complication.
Question 7: Which finding indicates that fluid resuscitation for a client in hypovolemic shock is effective?
- Heart rate increases from 110 to 130 bpm
- Urine output increases from 10 mL/hr to 40 mL/hr (Correct answer)
- Blood pressure drops from 90/60 to 80/50 mmHg
- Skin becomes cool and clammy
Correct answer: Urine output increases from 10 mL/hr to 40 mL/hr
Urine output of 30–50 mL/hr indicates adequate renal perfusion and is a key indicator of effective fluid resuscitation.
NACE Fluid and Electrolyte Balance 5
A client taking furosemide reports muscle cramps and weakness.
The nurse checks the lab results and finds a serum potassium of 3.1 mEq/L.
Which action is the priority?