A 75-year-old male with a history of CKD presents with weakness. His EKG shows peaked T waves and a widened QRS complex. Labs reveal potassium 7.8 mEq/L. Which of the following is the most immediate intervention to stabilize the cardiac membrane?

The correct answer to the question "A 75-year-old male with a history of CKD presents with weakness. His EKG shows peaked T waves and a widened QRS complex. Labs reveal potassium 7.8 mEq/L. Which of the following is the most immediate intervention to stabilize the cardiac membrane?" is Option C: Calcium gluconate intravenous..

The other options — A) Furosemide intravenous., B) Intravenous insulin and dextrose., D) Sodium polystyrene sulfonate orally. — are incorrect for this USMLE Exam Prep question. As explained above: With EKG changes (peaked T waves, widened QRS) in severe hyperkalemia, calcium gluconate is the most immediate intervention to stabilize the cardiac membrane and reduce arrhythmia risk.