A nurse is assessing a 68-year-old patient who has been receiving furosemide therapy for heart failure. Which assessment finding would be the priority concern indicating a serious electrolyte imbalance?

Scenario: A 68-year-old patient with heart failure on furosemide therapy presents with new-onset cardiac arrhythmias on telemetry.

• Assess the Patient: Immediately evaluate the patient's level of consciousness, airway, breathing, and circulation (ABCs). Check vital signs, including pulse rate and rhythm, blood pressure, and oxygen saturation.
• Verify the Rhythm: Confirm the arrhythmia on the monitor is real and not artifact. Obtain a 12-lead ECG if ordered and time permits, but do not delay treatment for a symptomatic, unstable patient.
• Activate Emergency Response: If the patient is unstable (e.g., hypotensive, chest pain, altered mental status), call the Rapid Response Team or activate the facility's emergency protocol immediately.

• STAT Labs: Prioritize a basic metabolic panel (BMP) to check serum potassium, sodium, creatinine, and BUN. A serum potassium level should be obtained urgently.
• Interpret Potassium Levels:
  • Hypokalemia (<3.5 mEq/L): Commonly expected with furosemide. Can cause U waves, flattened T waves, and ST depression on ECG.
  • Hyperkalemia (>5.0 mEq/L): Can occur with acute kidney injury or over-supplementation. ECG changes include peaked T waves, loss of P waves, and widened QRS complex, which can deteriorate into ventricular fibrillation or asystole.
• Other Labs: Check magnesium levels, as hypomagnesemia often coexists with hypokalemia and can exacerbate arrhythmias.

• For Unstable Hyperkalemia: Prepare to administer IV calcium gluconate or calcium chloride to stabilize the cardiac membrane. Anticipate orders for IV insulin with dextrose, IV sodium bicarbonate, or a beta-agonist (e.g., albuterol) to shift potassium intracellularly. Prepare for emergent hemodialysis if ordered.
• For Unstable Hypokalemia: Anticipate orders for IV potassium chloride replacement with continuous cardiac monitoring. Never administer IV potassium as a bolus.
• Hold Furosemide: The diuretic will likely be held until the electrolyte imbalance is corrected and the patient is stable.

• Continuous Telemetry: Maintain continuous cardiac monitoring to observe for rhythm changes during treatment.
• Frequent Vital Signs: Monitor blood pressure and heart rate every 5-15 minutes during an acute event.
• Fall Risk Precautions: Patients with arrhythmias or muscle weakness from electrolyte shifts are at high risk for falls. Keep the bed in the lowest position and the call light within reach.
• Documentation: Document the time of arrhythmia onset, the patient's symptoms, nursing actions taken, provider notifications, and the patient's response to interventions.

Reference: Priority setting follows the ABC (Airway, Breathing, Circulation) framework. A cardiac arrhythmia represents a direct threat to circulation and is the highest priority assessment finding in a patient with a potential electrolyte imbalance.