A 65-year-old male with ESRD on hemodialysis presents to the ED with weakness. ECG shows peaked T waves and a widened QRS complex. His serum potassium is 7.5 mEq/L. Which of the following is the most appropriate initial pharmacological agent to stabilize the cardiac membrane?

The correct answer to the question "A 65-year-old male with ESRD on hemodialysis presents to the ED with weakness. ECG shows peaked T waves and a widened QRS complex. His serum potassium is 7.5 mEq/L. Which of the following is the most appropriate initial pharmacological agent to stabilize the cardiac membrane?" is Option B: Calcium gluconate.

The other options — A) Intravenous insulin with glucose, C) Sodium polystyrene sulfonate, D) Furosemide — are incorrect for this USMLE Exam Prep question. As explained above: In severe hyperkalemia with ECG changes (peaked T waves, widened QRS), intravenous calcium gluconate is the most appropriate initial step. It directly antagonizes the cardiac effects of hyperkalemia,…