A 35-year-old man shows ECG signs of widening QRS complex and tall-tented T waves after a myocardial infarction. What is the most appropriate management?

In this scenario, the patient is exhibiting signs of hyperkalemia, which can occur following a myocardial infarction. The ECG findings of widened QRS complexes and tall, tented T-waves are classic indicators of elevated potassium levels that can lead to serious arrhythmias and other cardiac complications.

The most appropriate management in this case is intravenous calcium gluconate. Calcium plays a critical role in stabilizing the cardiac membrane and counteracting the effects of elevated potassium levels on cardiac electrical activity. By administering calcium gluconate intravenously, the risk of life-threatening arrhythmias is reduced, as calcium helps to stabilize the myocardium in the setting of hyperkalemia.

Other options listed, such as calcium resonium, are more suited for chronic management of hyperkalemia by promoting potassium excretion through the gastrointestinal tract, rather than immediate stabilization of cardiac function in acute scenarios. Oral calcium with vitamin D is not indicated in this acute setting and does not address the immediate risks associated with the life-threatening ECG changes caused by hyperkalemia. Intravenous sodium chloride could help with hydration and promote potassium excretion but does not directly counteract the cardiac effects of hyperkalemia as effectively as calcium does.

Therefore, the best and most immediate response to the