Correct Answer: A

Rationale: A serum potassium level of 5.5 mEq/L is most concerning in a client receiving erythropoietin therapy as it indicates hyperkalemia, requiring immediate intervention. High potassium levels can lead to severe cardiac arrhythmias and must be addressed promptly. The other laboratory values, though abnormal, do not present immediate life-threatening risks as hyperkalemia does.

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: B

Rationale: The correct answer is B: Liver function tests. Before administering methotrexate, it is crucial to review liver function tests due to the medication's potential hepatotoxic effects. Methotrexate can cause liver damage, so monitoring liver function is essential to prevent any serious complications. While white blood cell count, kidney function tests, and complete blood count are important parameters to monitor in certain situations, they are not the most critical before administering methotrexate.

Correct Answer: A

Rationale: The correct answer is to take alendronate on an empty stomach with a full glass of water. This instruction is essential to ensure proper absorption and prevent esophageal irritation. Taking alendronate with food, before bedtime with a light snack, or with milk can interfere with its absorption and effectiveness, leading to potential side effects or reduced therapeutic benefits.

Correct Answer: C

Rationale: The correct intervention when a nurse finds an irregular heart rate in a newborn is to document the finding in the infant's record. An irregular heart rate is a common occurrence in newborns and does not necessarily require immediate medical intervention. Notifying the pediatrician immediately is unnecessary unless there are other concerning symptoms. Teaching the parents about congenital heart defects is not the priority in this situation. Applying oxygen via nasal cannula at 3 L/min is not indicated for an irregular heart rate without further assessment or medical indication.