A nurse in an emergency department is caring for a client. Select the 4 actions the nurse should take.

A. Administer oxygen at 2 L/min via nasal cannula is correct because the client is showing signs of acute coronary syndrome (ACS) with worsening chest pain, tachycardia, tachypnea, and oxygen saturation dropping to 89%. Oxygen therapy helps improve myocardial oxygenation and reduces ischemia in hypoxic or unstable clients. B. Obtain arterial blood gases is not the priority action. While ABGs can provide information about oxygenation and acid-base status, the immediate priorities in suspected myocardial infarction are restoring coronary perfusion, improving oxygen delivery, and obtaining diagnostic confirmation via ECG and labs already trending positive for myocardial injury. C. Prepare to administer antiplatelet therapy is correct. The rising troponin levels and worsening symptoms indicate acute myocardial infarction. Antiplatelet therapy (such as aspirin or other platelet inhibitors) is essential to prevent further clot formation and limit myocardial damage. D. Perform a 12-lead ECG is correct. A 12-lead ECG is a key diagnostic tool for confirming myocardial infarction and identifying ST elevation or ischemic changes. It should be obtained immediately in a client with chest pain and elevated cardiac markers. E. Prepare the client for a cardiac catheterization is correct. Cardiac catheterization is indicated for definitive diagnosis and potential intervention (e.g., PCI/stent placement) in acute myocardial infarction, especially with rising troponins and worsening clinical status. F. Request a prescription for a sputum culture is incorrect because there is no indication of respiratory infection. The client’s symptoms are consistent with acute coronary syndrome, not pneumonia or infectious respiratory disease, so this intervention is not relevant or priority.