A 72-year-old man with chronic kidney disease presents to the emergency department with altered mental status. His labs show potassium 7.1 mEq/L, creatinine 4.5 mg/dL. ECG shows peaked T waves. What is the most appropriate immediate intervention to stabilize the cardiac membrane?

The correct answer to the question "A 72-year-old man with chronic kidney disease presents to the emergency department with altered mental status. His labs show potassium 7.1 mEq/L, creatinine 4.5 mg/dL. ECG shows peaked T waves. What is the most appropriate immediate intervention to stabilize the cardiac membrane?" is Option B: Intravenous calcium gluconate.

The other options — A) Intravenous insulin and dextrose, C) Sodium polystyrene sulfonate, D) Furosemide — are incorrect for this USMLE Exam Prep question. As explained above: In hyperkalemia with EKG changes (e.g., peaked T waves), intravenous calcium gluconate is the immediate first-line treatment. It stabilizes the cardiac membrane, preventing life-threatening arrhythmi…