The nurse is aware that the goal of using diltiazem 30 mg PO bid in the collaborative plan of care for a client diagnosed with variant (Prinzmetal's) angina is to:

Choice A reason: The pain you have is because your heart valves are damaged is not the most appropriate response. This statement may apply to a client with valvular heart disease, but not necessarily to a client with coronary artery disease. The nurse should explain that coronary artery disease is a condition that affects the blood vessels that supply the heart, not the heart valves.

Choice B reason: Your heart muscle is weak and is not pumping forcefully is not the most appropriate response. This statement may apply to a client with heart failure, but not necessarily to a client with coronary artery disease. The nurse should explain that coronary artery disease is a condition that reduces the blood flow to the heart, not the heart's contractility.

Choice C reason: The pain is caused by decreased oxygen to the heart muscle is the most appropriate response. This statement accurately describes the cause of angina, which is the chest pain that occurs when the heart does not receive enough oxygen due to narrowed or blocked coronary arteries. The nurse should also inform the client about the factors that can trigger or relieve angina, such as physical exertion, emotional stress, cold weather, or nitroglycerin.

Choice D reason: The layers of your heart are weak and thin is not the most appropriate response. This statement may apply to a client with cardiomyopathy, but not necessarily to a client with coronary artery disease. The nurse should explain that coronary artery disease is a condition that affects the blood vessels that supply the heart, not the heart's structure.

Choice A reason: Vitamin B12 does not contribute to the increased production of RBCs after significant blood loss. Vitamin B12 is a type of vitamin that is essential for the normal formation and maturation of red blood cells (RBCs), which carry oxygen throughout the body. ¹ However, vitamin B12 does not increase the production of RBCs in response to blood loss. That is the role of erythropoietin, a hormone that stimulates the bone marrow to produce more RBCs. ²

Choice B reason: Vitamin B12 is not needed to prevent excessive production of red blood cells. Vitamin B12 is needed for the normal production of red blood cells, not for the prevention of overproduction. Excessive production of red blood cells, also known as polycythemia, can cause the blood to become thick and viscous, increasing the risk of clotting and stroke. ³ Polycythemia can be caused by various factors, such as smoking, dehydration, or genetic mutations, but not by a lack of vitamin B12.

Choice C reason: Vitamin B12 is not needed to prevent RBCs from sticking together. Vitamin B12 is needed for the normal formation and maturation of RBCs, not for the prevention of aggregation. RBCs can stick together and form clumps, also known as rouleaux, which can impair blood flow and oxygen delivery. Rouleaux can be caused by various factors, such as inflammation, infection, or cancer, but not by a lack of vitamin B12.

Choice D reason: Vitamin B12 is needed for the normal formation and maturation of RBCs, but it cannot be absorbed by the body without a substance called intrinsic factor. Intrinsic factor is a protein that is produced by the stomach and binds to vitamin B12, allowing it to be absorbed by the small intestine. ¹ Pernicious anemia is a type of anemia that occurs when the stomach does not produce enough intrinsic factor, leading to vitamin B12 deficiency. The only way to treat pernicious anemia is by giving vitamin B12 injections, which bypass the need for intrinsic factor.