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: B

Rationale: Nitroglycerin is a rapid-acting medication used to relieve angina pain by dilating blood vessels. The correct administration is to take one tablet every 5 minutes as needed, up to three doses. If chest pain persists after three doses, the client should seek emergency medical attention as it can indicate a more serious cardiac issue.

Correct Answer: D

Rationale: Rotating the application site every 24 hours is essential to prevent skin irritation and ensure consistent absorption of the medication. This practice helps to maintain the effectiveness of the nitroglycerin patch and reduce the risk of local skin reactions.

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: Taking warfarin at the same time each day is crucial to maintain consistent blood levels and ensure the effectiveness of the medication in preventing clot formation. Consistent timing helps in monitoring and adjusting the dosage as needed to keep the international normalized ratio (INR) within the therapeutic range to prevent clotting events or excessive bleeding.