The client with pernicious anemia asks why vitamin B12 injections are necessary. What is the best response by the nurse?

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.

Choice A reason: Furosemide 40 mg PO daily is not the medication that the nurse should administer for chest pain. Furosemide is a diuretic that reduces fluid volume and lowers blood pressure, but it does not relieve anginal pain.

Choice B reason: Diltiazem 30 mg PO daily is not the medication that the nurse should administer for chest pain. Diltiazem is a calcium channel blocker that relaxes the blood vessels and lowers blood pressure, but it does not act quickly enough to relieve acute anginal pain.

Choice C reason: Metoprolol 25 mg PO bid is not the medication that the nurse should administer for chest pain. Metoprolol is a beta blocker that slows down the heart rate and lowers blood pressure, but it does not act quickly enough to relieve acute anginal pain.

Choice D reason: Nitroglycerin 0.4 mg SL PRN is the medication that the nurse should administer for chest pain. Nitroglycerin is a nitrate that dilates the coronary arteries and increases blood flow to the heart, thus relieving anginal pain. It is given sublingually (under the tongue) as needed for chest pain.