Correct Answer: A

Rationale: In a client with chronic kidney disease (CKD) receiving erythropoietin therapy, the nurse should closely monitor the serum potassium level. Erythropoietin therapy can increase red blood cell production, leading to a higher demand for potassium. Monitoring potassium levels is crucial to prevent hyperkalemia, a potential risk associated with this therapy. Hemoglobin level (Choice B) is important to assess the effectiveness of erythropoietin therapy, but monitoring potassium levels takes precedence due to the risk of hyperkalemia. White blood cell count (Choice C) and serum calcium level (Choice D) are not directly affected by erythropoietin therapy in the context of chronic kidney disease.

Correct Answer: C

Rationale: The correct answer is C. The use of accessory muscles in a client with COPD indicates increased work of breathing and may signal respiratory failure, requiring immediate intervention. This finding suggests that the patient is struggling to breathe effectively. Oxygen saturation of 90% is low but not critically low, while a respiratory rate of 24 breaths per minute is slightly elevated but not as concerning as the increased work of breathing indicated by the use of accessory muscles. Inspiratory crackles may be present in COPD due to underlying conditions like pneumonia but do not require immediate intervention as the use of accessory muscles does.

Correct Answer: A

Rationale: A white blood cell count of 2,000/mm³ is critically low and places the client at high risk for infection, requiring immediate intervention. Neutropenia, a low white blood cell count, is a common side effect of chemotherapy. A decreased white blood cell count compromises the immune system's ability to fight infections, making it a priority to address to prevent serious complications. Platelet count of 100,000/mm³ is relatively low but not as urgent as a severely low white blood cell count. Hemoglobin level of 10 g/dL is within the normal range for females and does not require immediate intervention. Serum creatinine level of 1.5 mg/dL is also within the normal range and does not pose an immediate threat to the client's health.

Correct Answer: A

Rationale: The correct answer is A, Magnesium hydroxide (Maalox). In clients with chronic kidney disease (CKD), magnesium can accumulate to toxic levels as the kidneys are unable to excrete it efficiently. This can lead to hypermagnesemia, causing serious and potentially life-threatening complications. Birth control pills (choice B) are metabolized mainly by the liver and do not pose a significant threat to clients with CKD. Cough syrup containing codeine (choice C) should be used cautiously in CKD due to the risk of respiratory depression but does not pose as great a threat as magnesium accumulation. Cold medication containing alcohol (choice D) should be avoided in CKD but does not present the same level of danger as magnesium toxicity.

Correct Answer: C

Rationale: Before a CT scan with contrast, the nurse should review the serum creatinine level. This is crucial in assessing kidney function because contrast agents can potentially worsen renal function, leading to contrast-induced nephropathy. Monitoring serum creatinine helps in identifying patients at risk and taking necessary precautions. Serum potassium (Choice A) is important in conditions like hyperkalemia but is not the priority before a contrast CT scan. Blood urea nitrogen (BUN) (Choice B) is another renal function test but is not as specific as serum creatinine for assessing kidney function. Serum glucose (Choice D) is important in monitoring blood sugar levels, especially in diabetic patients, but it is not directly related to the risk of contrast-induced nephropathy in this scenario.