Correct Answer: A

Rationale: The correct answer is A: International Normalized Ratio (INR). The INR should be closely monitored in a client receiving warfarin (Coumadin) to assess the effectiveness and safety of anticoagulation therapy. Monitoring the INR helps ensure that the client is within the therapeutic range to prevent both bleeding and clotting events. Choices B, C, and D are incorrect because while PT is used to monitor warfarin therapy, INR is a more precise indicator of therapeutic levels. Serum sodium level and hemoglobin level are not directly related to monitoring warfarin therapy.

Correct Answer: A

Rationale: The correct answer is A: Serum potassium level. In clients receiving erythropoietin therapy for chronic kidney disease, monitoring serum potassium levels is crucial due to the risk of developing hyperkalemia. Erythropoietin therapy can stimulate red blood cell production, leading to an increase in potassium levels. Monitoring potassium levels helps prevent complications associated with hyperkalemia, such as cardiac arrhythmias. Choices B, C, and D are incorrect because while hemoglobin levels are relevant for assessing the effectiveness of erythropoietin therapy, monitoring potassium levels is more critical due to the potential adverse effects of elevated potassium levels in CKD patients on this therapy.

Correct Answer: C

Rationale: To calculate the infusion rate, convert 1 mg to 1,000 mcg (1 mg = 1,000 mcg) and then use the formula D/H x Q, where D is the desired dose, H is the dose on hand, and Q is the quantity of solution. In this case, it would be 300 mcg/hour / 1,000 mcg x 250 ml = 75 ml/hour. Therefore, the nurse should program the infusion pump to deliver 75 ml/hour. Choice A (50 ml/hour), Choice B (25 ml/hour), and Choice D (100 ml/hour) are incorrect as they do not correspond to the calculated rate of 75 ml/hour.

Correct Answer: A

Rationale: The correct answer is A. A 3-pound weight gain in two days indicates fluid retention and worsening heart failure, which requires immediate assessment. This could be a sign of decompensation in the client's condition, necessitating prompt evaluation and intervention. Choices B, C, and D do not present an immediate threat to the client's health and can be addressed after assessing the client with congestive heart failure.

Correct Answer: C

Rationale: The nurse uses the bell of the stethoscope to hear low-pitched sounds such as S3 and S4. To determine if an S3 heart sound is present, the nurse should listen at the same location using the bell first. This allows for the accurate identification of low-pitched sounds. Moving the stethoscope across the sternum (Choice A) or to the mitral site (Choice B) would not be the initial actions to assess for an S3 heart sound. Observing the cardiac telemetry monitor (Choice D) is not relevant for assessing S3 heart sounds, as it does not provide direct auscultation of heart sounds.