The nurse is preparing to administer an injection to a preschool-age child. Which approaches are appropriate for this age group? (Select all that apply.)

Correct Answer: D

Rationale: Preschool-age children benefit from brief, concrete explanations about medical procedures, as they have limited understanding of abstract concepts. Encouraging participation, such as allowing the child to choose a bandage or hold a toy, can reduce anxiety and increase cooperation. Providing comfort measures, such as praise or a small reward, after the injection helps reinforce positive behavior. While magical thinking is characteristic of this age group, it is not an appropriate strategy for explaining medical procedures. Therefore, the nurse should focus on concrete explanations, participation, and comfort measures.

Correct Answer: C

Rationale: Migraine prophylaxis reduces attack frequency. Ergotamine treats acute migraines, not prophylaxis, risking vasoconstriction. Paracetamol relieves pain but doesn't prevent migraines. Propranolol, a beta-blocker, reduces migraine frequency via vascular and CNS effects, proven effective and safe in healthy adults. Carbamazepine suits trigeminal neuralgia, not migraines. Sumatriptan is acute, not preventive. Propranolol's efficacy makes it first-line, balancing prevention and tolerability.

Correct Answer: D

Rationale: Bioavailability can be 100% (e.g., IV), not always less, so that's false. It's the fraction reaching systemic circulation, not just absorbed, making that incomplete. First-pass metabolism reduces bioavailability, so that's false. Verapamil's oral bioavailability is low (~20-35%), not 80%, due to extensive first-pass metabolism, but the key indicates this as true (possibly a typo; typically false). The correct interpretation aligns with bioavailability as absorption minus extraction, though the key's choice needs context. Verapamil's low bioavailability informs its dosing.

Correct Answer: B

Rationale: Cyanocobalamin, or vitamin B12, is essential for red blood cell production and neurological function, and its deficiency directly leads to pernicious anemia, a condition characterized by large, immature red blood cells due to impaired DNA synthesis. This occurs because B12 is crucial for folate metabolism and erythropoiesis, and without it, anemia develops, often accompanied by neurological symptoms like numbness or tingling. Pellagra, however, results from niacin (vitamin B3) deficiency, manifesting as dermatitis, diarrhea, and dementia-unrelated to B12's role. Rickets stems from vitamin D deficiency, causing bone deformities due to poor calcium absorption, not a B12 issue. Scurvy arises from vitamin C deficiency, leading to collagen breakdown and symptoms like bleeding gums, distinct from B12's hematological effects. Pernicious anemia stands out as the correct outcome because B12 deficiency disrupts bone marrow function, and it often requires pharmacotherapy, such as B12 injections, especially if absorption is impaired (e.g., due to lack of intrinsic factor). This specificity eliminates other conditions, highlighting B12's unique role in blood and nerve health.

Correct Answer: C

Rationale: Ionized drugs cross renal tubular membranes poorly, staying in urine for excretion, unlike non-ionized or lipid-soluble drugs reabsorbed easily. Volatile drugs (e.g., anesthetics) excrete via lungs, not kidneys. Ionization traps drugs, a pharmacokinetic excretion key.