Correct Answer: B

Rationale: The correct answer is to verify the client's blood type and Rh factor. This action is crucial to ensure that the correct blood is administered, matching the client's blood type and Rh factor, which helps prevent transfusion reactions. Priming the IV tubing with 0.9% sodium chloride (Choice A) is not directly related to ensuring the correct blood product is administered. Administering the blood over 8 hours (Choice C) is not the standard practice for packed RBCs, which are usually given over a shorter period. Using a 22-gauge needle for venous access (Choice D) is not specific to the preparation for administering packed RBCs.

Correct Answer: D

Rationale: The correct answer is D. A nonstress test measures the fetal heart's response to movement, helping to assess fetal well-being. Choice A is incorrect as the duration of the test can vary, and it is not always precisely 30 minutes. Choice B is incorrect as drinking water is not necessary for a nonstress test. Choice C is incorrect as having a full bladder is not required for this test.

Correct Answer: B

Rationale: The correct answer is B. Phenytoin can decrease the effectiveness of oral contraceptives, so it is important to inform the client about this interaction. Using an additional form of contraception, such as a backup method, is recommended to ensure adequate protection against pregnancy. Choice A is incorrect because it lacks specificity about the decrease in effectiveness of oral contraceptives caused by phenytoin. Choice C is incorrect as it suggests stopping phenytoin use while using oral contraceptives, which is not the appropriate action. Choice D is incorrect as phenytoin is known to decrease, not increase, the effectiveness of oral contraceptives.

Correct Answer: A

Rationale: The correct answer is A: Low back pain. Low back pain is a common sign of a hemolytic transfusion reaction, indicating the destruction of red blood cells. This finding requires immediate intervention as it can lead to serious complications such as renal failure. Bradycardia (choice B) is not typically associated with a hemolytic transfusion reaction. Chills (choice C) can be seen in febrile non-hemolytic transfusion reactions. Distended neck veins (choice D) are more indicative of fluid overload rather than a hemolytic reaction.

Correct Answer: B

Rationale: Keeping the client's legs elevated is the appropriate action to prevent venous thromboembolism following a total knee arthroplasty. Elevating the legs helps promote circulation and reduce the risk of blood clots. Placing a pillow under the client's knees may provide comfort but does not address the specific postoperative complication. Flexing the client's knee every 2 hours may be contraindicated as excessive movement can disrupt the surgical site. Applying heat to the operative knee is not recommended immediately postoperatively as it can increase swelling and discomfort.