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.

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: 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.

Correct Answer: C

Rationale: When a client with heart failure is prescribed furosemide, the nurse should monitor for hypokalemia. Furosemide is a loop diuretic that can lead to potassium loss, which increases the risk of hypokalemia. Hypokalemia can have serious implications such as cardiac dysrhythmias. Therefore, it is essential to closely monitor the client's serum potassium levels while on furosemide to prevent complications.