Correct Answer: A

Rationale: Prothrombin time (PT) and international normalized ratio (INR) are essential laboratory tests to monitor the effectiveness of anticoagulant therapy in clients with atrial fibrillation. These tests help ensure that the client is within the therapeutic range and are commonly used to assess the clotting ability of the blood. Monitoring PT and INR levels allows healthcare providers to adjust anticoagulant dosages as needed to prevent complications such as bleeding or thrombosis.

Correct Answer: A

Rationale: The correct answer is A: 'Report any weight gain of more than 2 pounds in a day.' Sudden weight gain of more than 2 pounds in a day may indicate fluid retention and worsening heart failure. This information is crucial for early intervention and monitoring of the client's condition. Weighing after eating breakfast (choice B) may not provide consistent results due to varying food and fluid intake. Using the same scale each day (choice C) ensures accuracy and consistency in weight measurements. Recording weight daily (choice D) is more frequent than necessary and may not be practical for all clients, making it important to focus on significant weight changes instead.

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: C

Rationale: Hypokalemia increases the risk of digoxin toxicity as low potassium levels enhance the effects of digoxin on the heart, leading to toxicity and potential adverse effects.

Correct Answer: B

Rationale: It is essential to rotate the application site of the nitroglycerin patch to prevent skin irritation and ensure consistent absorption of the medication. Applying it to the same site can lead to skin irritation and decreased effectiveness.