ATI LPN
Introduction of Respiratory System NCLEX Questions PN Questions
Question 1 of 5
Regarding the alveolar gas equation:
Correct Answer: A
Rationale: RQ nears 1.0 in exercise (e.g., 0.8 to 1.2) as metabolism shifts. Choice B is true but incomplete; PIO₂ = FiO₂ · (PB - PH₂O). Choice C is false; PACO₂ ≈ PaCO₂ (≈40 mmHg) in normals. Choice D is wrong; PAO₂ ≈ 100 mmHg (150 - 40/0.8), not 150. Exercise increases VCO₂ relative to VO₂, raising RQ, especially anaerobically. The equation (PAO₂ = PIO₂ - PACO₂/RQ) adjusts dynamically, making A the accurate statement.
Question 2 of 5
All of the following are features of acclimatisation to high altitude EXCEPT:
Correct Answer: C
Rationale: high altitude causes pulmonary vasoconstriction (hypoxic response), not vasodilation. Choice A is true; 2,3-DPG shifts the curve right. ' angiogenesis increases capillaries. Choice D is accurate; polycythemia boosts Hb. Choice E (breathing capacity) rises. Vasoconstriction matches V/Q, countering hypoxia, making C the exception.
Question 3 of 5
Fick's law states that:
Correct Answer: B
Rationale: Fick's law states gas diffusion rate (V) = (A · D · (P1-P2)) / T, where A is area, D is diffusion constant, P1-P2 is pressure gradient, and T is thickness. Choice A is the alveolar ventilation equation, not Fick's. Choice C is the pH definition, unrelated. Choice D is Boyle's law (gas volume-pressure). Choice E is a temperature ratio misstep. Fick's law governs O₂ and CO₂ transfer across the alveolar-capillary membrane, emphasizing area and gradient (e.g., DₗO₂ ≈ 25 mL/min/mmHg), inversely proportional to thickness. B accurately captures this principle, critical for lung gas exchange calculations.
Question 4 of 5
Which of the following DOES NOT constrict pulmonary arterioles?
Correct Answer: D
Rationale: isoproterenol (β₂-agonist) dilates pulmonary arterioles, not constricts. Choice A (adrenaline) constricts via α-receptors (β₂ dilates, but α dominates in lung). Choice B (thromboxane B₂) constricts (stable metabolite). Choice C (noradrenaline) constricts (α-effect). Choice D (prostaglandin F2α) constricts. Isoproterenol's β₂-stimulation reduces resistance, aiding flow, distinguishing E as the non-constrictor.
Question 5 of 5
The pediatric nurse is talking to a young child's grandmother, who cares for the child during the work week. The grandmother can't remember whether she gave aspirin or acetaminophen when the child had a fever. What is the best advice the pediatric nurse can give the grandmother for the future?
Correct Answer: A
Rationale: Aspirin is contraindicated in children with fever, especially during viral illnesses like the flu, due to the risk of Reye's syndrome, a rare but severe condition affecting the liver and brain. Acetaminophen is a safer choice for fever reduction in children, widely recommended by healthcare providers. Advising the grandmother to avoid aspirin protects the child from this potentially fatal complication, which is linked to aspirin use in viral infections. Keeping a record of medications is helpful but secondary to ensuring safety by avoiding harmful drugs. Telling the grandmother not to use acetaminophen would be incorrect, as it's effective and safe when dosed properly. Claiming aspirin and acetaminophen are equally suitable ignores the significant risks associated with aspirin in this context. The nurse's primary responsibility is to prevent harm, making the advice to avoid aspirin the most critical and evidence-based recommendation for future fever management in the child.