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: 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: 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: The correct laboratory test result that the LPN/LVN should monitor to ensure the client is receiving a therapeutic dose of heparin therapy is the activated partial thromboplastin time (aPTT). The aPTT test is specifically used to monitor heparin therapy, ensuring that the dose administered is within the therapeutic range. Monitoring aPTT helps to prevent complications such as bleeding or clot formation by maintaining the appropriate anticoagulant effect of heparin.

Correct Answer: B

Rationale: Removing the nitroglycerin patch at night is essential to prevent the development of tolerance. Tolerance can occur when the body gets used to a constant level of the medication, reducing its effectiveness. By removing the patch at night, the client has a drug-free period, which helps prevent tolerance and maintains the effectiveness of the nitroglycerin for angina relief.