The nurse is observing the auscultation technique of another nurse.
The correct method to use when progressing from one auscultatory site on the thorax to another is:

Choice A rationale

Giving water after a buccal medication would cause the medication to be swallowed. Buccal medications are designed for absorption through the rich vascularization of the buccal mucosa, allowing direct entry into the systemic circulation and bypassing first-pass hepatic metabolism. Swallowing defeats this purpose.

Choice B rationale

Buccal medications are intended to dissolve slowly in the buccal pouch (between the cheek and gums) and be absorbed directly into the bloodstream through the mucous membranes. Consuming water would wash the medication away, leading to premature swallowing and subsequent degradation by gastric enzymes or first-pass metabolism in the liver, thus reducing its therapeutic effect.

Choice C rationale

The client's preference for water does not supersede the pharmacokinetic principles governing buccal medication administration. The route of administration is chosen specifically for its absorption profile, and introducing water compromises the intended local absorption mechanism, regardless of patient comfort.

Choice D rationale

The type of medication is precisely why water should be avoided. Buccal medications, by their very design, rely on sustained contact with the oral mucosa for systemic absorption. Regardless of the specific drug, water interferes with this fundamental mechanism, rendering the buccal route ineffective.

Choice A rationale

Ordering a trough level 4 hours before the next scheduled dose would likely result in an inaccurate reading. The trough level represents the lowest concentration of a drug in the bloodstream, typically occurring just before the next dose, ensuring that the drug concentration remains within the therapeutic range to exert its pharmacological effect.

Choice B rationale

Obtaining a trough level 24 hours after the drug was given is too late and would not provide an accurate assessment of the drug's lowest concentration before the subsequent dose. By this time, depending on the drug's half-life, the concentration may be significantly lower or undetectable, making it irrelevant for therapeutic monitoring.

Choice C rationale

The trough level of a medication is measured to ensure that the drug concentration remains above the minimum effective concentration and below toxic levels. Collecting the blood sample 30 minutes before the administration of the next dose allows the drug to reach its lowest concentration in the systemic circulation, providing an accurate representation of the drug's true trough level.

Choice D rationale

Measuring the drug level 1 hour after the medication has been infused would represent a concentration much closer to the peak level, not the trough. The peak level indicates the maximum drug concentration, typically occurring shortly after administration or infusion, and is used to assess for potential toxicity or adequate absorption.