A nurse is preparing to administer a beta-blocker to a client with hypertension. Which of the following actions should the nurse prioritize?

B) Correct. Beta-blockers primarily affect the heart by decreasing heart rate and contractility. Before administering a beta-blocker, it is essential for the nurse to assess the client's heart rate and rhythm to ensure it is within an appropriate range. This is important because beta-blockers can further slow the heart rate and may be contraindicated in certain conditions, such as bradycardia or heart block.

A) Incorrect. Although checking the client's blood pressure is important, it is not the priority action when administering a beta-blocker.

C) Incorrect. Evaluating renal function is not directly related to the administration of a beta-blocker. However, renal function should be considered in the overall assessment of the client's health status.

D) Incorrect. Monitoring blood glucose levels is not directly related to the administration of a beta-blocker. This action is more relevant for clients with diabetes who are taking medications that can affect blood glucose levels.

C) Correct. Heparin primarily affects the intrinsic pathway of the coagulation cascade, and the activated partial thromboplastin time (aPTT) is the laboratory test used to monitor the client's response to heparin therapy. The aPTT provides information about the time it takes for the client's blood to clot and helps determine the appropriate heparin dosage.

A) Incorrect. Prothrombin time (PT) is used to monitor clients receiving warfarin therapy, not heparin.

B) Incorrect. International normalized ratio (INR) is also used to monitor clients receiving warfarin therapy, not heparin.

D) Incorrect. Platelet count is important to monitor for heparin-induced thrombocytopenia (HIT), a potential adverse effect of heparin therapy, but it does not directly assess the client's response to heparin therapy.