The nurse is preparing to administer medications through a tube.
Which of the following should she remember before administering the medications?

Choice A rationale

Cerumen, or earwax, is a normal physiological secretion produced by the apocrine and sebaceous glands in the external auditory canal. While excessive or impacted cerumen can lead to conductive hearing loss or harbor bacterial growth, its mere presence, especially in a healthy individual, is not indicative of an external ear infection. An infection would typically present with pain, redness, discharge, or fever.

Choice B rationale

Cerumen is a natural substance composed of exfoliated skin cells, fatty acids, cholesterol, and lysozymes. It serves a protective role by lubricating the ear canal, trapping dust and foreign particles, and possessing antibacterial and antifungal properties. Its presence in the external auditory meatus, as observed in this patient, is a normal physiological finding.

Choice C rationale

While skin conditions like eczema can affect the external ear canal and lead to inflammation, itching, and scaling, the presence of cerumen alone does not indicate eczema lesions. Eczema would typically present with characteristic erythematous, pruritic, and possibly weeping or crusted lesions, which are distinct from normal cerumen.

Choice D rationale

Cerumen production is a normal bodily function and its presence is not an indicator of poor hygiene. Attempts to excessively clean the ear canal with cotton swabs can actually push cerumen deeper, leading to impaction, rather than indicating poor hygiene. The ear is generally self-cleaning, with cerumen naturally migrating out of the canal.

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.