Correct Answer: A

Rationale: Pain is a subjective experience, and the client's report of pain should be taken seriously even if there are no outward signs. Choice B is incorrect because pain can be present without observable symptoms, and waiting for observable signs may delay appropriate pain management. Choice C is incorrect because the safety of long-term opioid use in elderly clients is a complex issue and should be carefully evaluated due to the risk of adverse effects. Choice D is incorrect because while pain reassessment is important, it should not be limited to just after medication administration but should occur regularly to ensure adequate pain control.

Correct Answer: A

Rationale: Astrocytes play a crucial role in supporting and nourishing neurons by providing metabolic support, maintaining the blood-brain barrier, and regulating the chemical environment of the brain. While astrocytes are essential for brain function, they are not neurons and do not transmit electrical signals (Choice B). Astrocytes are not primarily involved in immune responses in the brain (Choice C) or in regulating blood flow in the brain (Choice D), although they indirectly influence blood flow through their support functions.

Correct Answer: B

Rationale: Corrected Rationale: A client with atrial fibrillation is at increased risk of thromboembolism due to blood stasis in the atria. This can lead to the formation of blood clots, which may travel to the lungs and cause a pulmonary embolism. Pulmonary embolism is a serious complication of atrial fibrillation. Choices A, C, and D are incorrect because while atrial fibrillation can lead to complications such as stroke or heart failure, it is specifically associated with an increased risk of pulmonary embolism due to the clot formation associated with the condition.

Correct Answer: D

Rationale: A rash from poison ivy is an example of a type IV hypersensitivity reaction. Type IV hypersensitivity reactions are delayed cell-mediated immune responses involving T cells. This type of reaction is characterized by a delayed onset, typically occurring 48-72 hours after exposure to the antigen. Choice A, Type I hypersensitivity reactions, are immediate hypersensitivity reactions mediated by IgE antibodies. Choices B and C, Type II and Type III hypersensitivity reactions, involve antibody-mediated cytotoxicity and immune complex deposition, respectively, which are not characteristic of poison ivy-induced rashes.

Correct Answer: B

Rationale: The correct answer is B: Aldesleukin (Proleukin). Aldesleukin is a medication used in the treatment of metastatic kidney cancer. It is a recombinant interleukin-2 that works by stimulating the immune system to attack cancer cells. Choice A, Filgrastim, is a medication used to stimulate the production of white blood cells. Choice C, Interferon alfa-2b, is used in the treatment of certain cancers but not specifically metastatic kidney cancer. Choice D, Darbepoetin alfa, is used to treat anemia by stimulating red blood cell production and is not indicated for metastatic kidney cancer.