The physician orders local application of epinephrine 1:1000 solution to treat a nosebleed. The patient asks how this will help. Which of the ff. responses by the nurse is best?

Correct Answer: D

Rationale: Epinephrine is a vasoconstrictor, which means it causes blood vessels to narrow. When applied locally to the site of a nosebleed, epinephrine constricts the blood vessels in the nose, slowing down and stopping the bleeding. By constricting the blood vessels, epinephrine helps to reduce the blood flow to the area, allowing a clot to form and stop the bleeding. This is why option D, "It will constrict your vessels and slow down the bleeding," is the best response by the nurse to explain how epinephrine will help treat a nosebleed.

Correct Answer: A

Rationale: Warfarin is an anticoagulant medication that works by inhibiting the production of certain clotting factors in the liver, thus prolonging the time it takes for blood to clot. An elevated INR level indicates that the blood is taking longer to clot than desired, potentially putting the patient at risk for bleeding. Vitamin K is the antidote for warfarin because it helps the liver produce these clotting factors, ultimately reversing the effects of warfarin and promoting normal blood clotting. Administering Vitamin K helps lower the INR level and reduce the risk of bleeding in patients on warfarin therapy. Therefore, in this scenario, Vitamin K would be the appropriate antidote to use for the patient with an elevated INR level.

Correct Answer: C

Rationale: In humoral immunity, the activation of B cells is facilitated by helper T cells. Helper T cells play a crucial role in coordinating the immune response by interacting with B cells. They secrete cytokines that stimulate B cells to proliferate and differentiate into antibody-secreting plasma cells. Without the assistance of helper T cells, the activation of B cells and the production of antibodies would be impaired. Cytotoxic T cells are involved in cell-mediated immunity, supressor T cells regulate immune response, and neutrophils are involved in phagocytosis and innate immunity, but they do not directly assist in B cell activation in humoral immunity.

Correct Answer: A

Rationale: An anaphylactic reaction is considered a Type I hypersensitivity reaction. In Type I hypersensitivity, the immune system produces IgE antibodies in response to an allergen, leading to the release of various inflammatory mediators like histamine. This immediate systemic reaction can cause symptoms such as hives, itching, swelling, difficulty breathing, and in severe cases, anaphylactic shock. These reactions occur quickly, typically within minutes to hours after exposure to the allergen. Anaphylaxis is a medical emergency that warrants immediate intervention with epinephrine and supportive care.

Correct Answer: B

Rationale: ELISA (Enzyme-Linked Immunosorbent Assay) and Western Blot are the two main tests used to confirm HIV infection. ELISA is typically the first test performed to detect HIV antibodies in the blood. If the ELISA test is positive, the Western Blot test is then used to confirm the presence of HIV antibodies and differentiate between HIV-1 and HIV-2 antibodies. Both tests are highly sensitive and specific in diagnosing HIV infection. Other tests like CD4+ count and viral load are used to monitor disease progression but are not used primarily to confirm HIV infection.