Correct Answer: B

Rationale: Obtaining an ECG is crucial in this situation because it helps in assessing for potential complications, such as a recurrent MI or ongoing ischemia. This diagnostic test provides valuable information to guide further interventions and treatment. Administering morphine, oxygen, or nitroglycerin may be necessary but obtaining an ECG takes precedence to evaluate the cardiac status and determine the appropriate course of action.

Correct Answer: B

Rationale: The correct answer is serum potassium. Monitoring serum potassium levels is crucial when a client is receiving digoxin (Lanoxin) because low potassium levels can increase the risk of digoxin toxicity. Digoxin and low potassium levels can lead to serious cardiac complications, such as arrhythmias. Therefore, close monitoring of serum potassium is essential to prevent adverse effects and ensure the safe administration of digoxin in clients with heart failure.

Correct Answer: A

Rationale: Shortness of breath and frothy sputum are indicative of pulmonary edema, a serious condition that requires immediate intervention to improve oxygenation. Administering oxygen is the priority action to support the client's respiratory function and prevent further deterioration. Oxygen therapy helps increase the oxygen levels in the blood, alleviate respiratory distress, and support vital organ function. Prompt intervention with oxygen can help stabilize the client while further assessments and treatments are initiated.

Correct Answer: A

Rationale: The correct instruction is to take aspirin with food to prevent gastrointestinal upset. Aspirin can irritate the stomach lining, leading to potential gastrointestinal issues. Taking it with food helps reduce this risk by providing a protective layer in the stomach. This is a common recommendation to minimize the risk of gastrointestinal side effects when taking aspirin.

Correct Answer: C

Rationale: Atenolol is a beta-blocker that commonly causes hypotension by lowering blood pressure. Therefore, monitoring for hypotension is crucial to prevent potential complications in the client receiving this medication.