Correct Answer: B

Rationale: The correct instruction for a client prescribed levothyroxine is to take the medication at the same time every day. This consistency is important for maintaining stable thyroid hormone levels. Choice A is incorrect because levothyroxine should be taken on an empty stomach to ensure proper absorption. Choice C is important but not directly related to the administration of levothyroxine. Choice D is incorrect as antacids can interfere with the absorption of levothyroxine.

Correct Answer: C

Rationale: Corrected Rationale: The nurse should monitor the client's INR to determine the effectiveness of warfarin therapy. INR monitoring is crucial as it reflects the blood's ability to clot properly. Warfarin is commonly used as an anticoagulant, and maintaining the INR within the therapeutic range ensures that the client is protected from both clotting and bleeding events. Monitoring serum calcium levels, platelet count, or WBC count is not directly related to assessing the effectiveness of warfarin therapy.

Correct Answer: C

Rationale: Auscultating crackles in the lung bases indicates fluid in the lungs, which can be a sign of aspiration pneumonia or pulmonary edema and requires immediate intervention to prevent respiratory distress. Aspirating 100 mL of gastric residual is within the acceptable range and does not require immediate intervention. A gastric pH of 4 is normal for gastric contents. Checking residual every 6 hours is a routine nursing intervention and does not indicate an urgent issue like pulmonary complications.

Correct Answer: B

Rationale: An aPTT of 60 seconds indicates the client is receiving an effective dose of heparin. The activated partial thromboplastin time (aPTT) measures the time it takes for a clot to form, and a therapeutic range for heparin therapy is usually 1.5 to 2 times the control value, which is around 60-80 seconds. An INR of 1.5 is not related to heparin therapy, as it is commonly used to monitor warfarin therapy. Platelet count and potassium levels are not direct indicators of the effectiveness of heparin therapy.

Correct Answer: A

Rationale: The correct answer is A: Hypokalemia. Furosemide, a loop diuretic, can lead to potassium loss in the urine, resulting in hypokalemia. This electrolyte imbalance is commonly seen in patients taking furosemide and requires close monitoring. Choices B, C, and D are incorrect because furosemide does not typically cause hyponatremia, hyperkalemia, or hypercalcemia as frequently as it causes hypokalemia.