Name the following arterial blood gas (ABG) values: pH 7.47, PaCO2 32, HCO3- 23

Choice A reason: Long-term proton pump inhibitor (PPI) use has a weak, controversial association with gastric cancer due to hypergastrinemia, but evidence is inconclusive. In older patients, risks like osteoporosis and nutrient deficiencies are more established and immediate concerns, making this choice less consistently worrisome compared to others.

Choice B reason: PPIs reduce gastric acid, impairing calcium absorption, which increases osteoporosis risk in older patients. Chronic use is linked to decreased bone density and higher fracture risk, particularly in the elderly, due to disrupted mineral homeostasis, making this a significant and correct adverse effect to monitor.

Choice C reason: PPIs inhibit acid production, reducing absorption of vitamin B12, magnesium, and iron, leading to deficiencies in older patients. These can cause anemia, neurological issues, or hypomagnesemia, which are particularly concerning in the elderly due to comorbidities, making this a correct and critical adverse effect.

Choice D reason: Headaches are a possible PPI side effect but are less common and less severe in older patients compared to osteoporosis, nutrient deficiencies, or drug interactions. They don’t pose a significant long-term risk or require specific monitoring, making this choice incorrect for major concerns.

Choice E reason: PPIs interact with drugs like clopidogrel, reducing its efficacy by inhibiting CYP2C19, and affect absorption of drugs requiring acidic environments. In older patients with polypharmacy, these interactions increase risks of adverse outcomes, making this a significant and correct concern for PPI use.

Choice A reason: Lipid-soluble drugs cross cell membranes quickly due to their affinity for lipid bilayers, leading to predictable, rapid absorption. Their onset is not unpredictable but typically faster than water-soluble drugs, especially via routes like intravenous or transdermal, making this choice incorrect for lipid-soluble drugs.

Choice B reason: Lipid-soluble drugs, like fentanyl, rapidly cross lipid-rich cell membranes, including the blood-brain barrier, leading to quick onset of action. This is due to their high partition coefficient, allowing fast diffusion into tissues, making rapid effect onset the correct expectation for the nurse.

Choice C reason: Lipid-soluble drugs have faster onset than water-soluble drugs due to easier membrane penetration. Slow effects are more typical of water-soluble or poorly absorbed drugs. Lipid solubility enhances rapid distribution and action, making this choice incorrect for the expected effect timeline.

Choice D reason: Osmosis refers to water movement across membranes, not drug absorption. Lipid-soluble drugs diffuse through lipid bilayers, not via osmosis, which is irrelevant to their pharmacokinetics. This choice is scientifically inaccurate for describing the onset of lipid-soluble drug effects.