Correct Answer: D

Rationale: Maintaining sterile technique when handling a central venous catheter is crucial in preventing infections. Changing the catheter dressing every 72 hours, while important for overall catheter care, does not directly address infection prevention. Flushing the catheter with heparin solution daily is essential for maintaining patency but does not primarily prevent infections. Ensuring the catheter is clamped when not in use is important for preventing air embolism but is not the most critical action to prevent infection. The most effective way to prevent infections is by strictly adhering to sterile techniques during catheter handling, which minimizes the risk of introducing pathogens into the catheter site.

Correct Answer: A

Rationale: Checking the client's pupillary reaction to light is a key assessment to evaluate the oculomotor nerve function. The oculomotor nerve controls the pupil's constriction response to light. Choices B, C, and D are incorrect because testing vision with a Snellen chart, identifying scents, or touching the cornea are not specific assessments for oculomotor nerve function.

Correct Answer: A

Rationale: The appropriate initial action for the nurse is to examine the elbow. This step is crucial to assess the site of pain, identify any visible signs of injury or inflammation, and determine the cause of the discomfort. Administering pain medication (Choice B) should come after a thorough assessment. Applying a warm compress (Choice C) might provide temporary relief but does not address the underlying cause. Assessing the client's range of motion (Choice D) is important but would come after the initial examination to further evaluate the elbow joint.

Correct Answer: C

Rationale: The correct answer is C: Prothrombin time (PT). Prothrombin time is monitored to assess the therapeutic response to warfarin therapy. Warfarin works by inhibiting vitamin K-dependent clotting factors, which prolongs the PT. Monitoring PT helps determine if the client's blood is clotting within the desired therapeutic range. Choices A, B, and D are incorrect because bleeding time, coagulation time, and partial thromboplastin time are not specifically used to monitor the therapeutic response to warfarin. Bleeding time assesses platelet function, coagulation time is a general term and not a specific test, and partial thromboplastin time is more relevant in monitoring heparin therapy, not warfarin.

Correct Answer: D

Rationale: Acupuncture has been effective for the client previously, supporting continued use.