A 72-year-old client with a history of heart failure is prescribed furosemide 40 mg orally daily. Which finding in the client's morning lab results would require the nurse to hold the medication and notify the primary healthcare provider?

Question: A 72-year-old client with a history of heart failure is prescribed furosemide 40 mg orally daily. Which finding in the client's morning lab results would require the nurse to hold the medication and notify the primary healthcare provider?

Answer options:

• Sodium 138 mmol/L ✅ Potassium 2.8 mmol/L
• Creatinine 100 µmol/L
• Glucose 6.5 mmol/L

Correct answer: Potassium 2.8 mmol/L

Explanation: Furosemide is a loop diuretic that causes potassium excretion. A potassium level of 2.8 mmol/L is profoundly hypokalemic and could lead to cardiac dysrhythmias, necessitating immediate intervention before administering the diuretic.