Which electrolyte disturbance is specifically monitored due to risk of dysrhythmias and muscle weakness after CABG?

• A. Hyperkalemia
• B. Hypokalemia
• C. Hypercalcemia
• D. Hyponatremia

Answer: (B)

Potassium balance is crucial for normal heart rhythm and skeletal muscle function. After CABG, patients commonly lose potassium through urine and other routes, and shifts into cells can occur because of metabolic alkalosis, insulin use, and catecholamines in the perioperative period. This makes low potassium a frequent and serious postoperative issue. Hypokalemia destabilizes the cardiac cell membrane and delays repolarization, increasing the risk of dysrhythmias, and it also weakens skeletal muscles, including those needed for breathing. Because preventing rhythm problems and muscle weakness is a priority during recovery, potassium levels are closely monitored and corrected as needed after CABG.