A home health nurse is visiting a new client who uses oxygen in the home.
For which factors does the nurse assess when determining if the client is using the oxygen safely? (Select all that apply)

Choice A rationale

A decrease in respiration rate from 40 to 32 breaths/min in an infant with RSV, while a reduction, does not necessarily indicate immediate deterioration requiring urgent reporting unless accompanied by other signs of respiratory distress. The normal respiratory rate for an infant typically ranges from 30 to 60 breaths/min. This change might reflect an improvement or a less acute phase.

Choice B rationale

A decrease in heart rate from 110 to 100 beats/min in an infant, while a slight reduction, still falls within the normal range for an infant's heart rate (typically 90-160 beats/min). This change alone is not usually indicative of immediate critical deterioration, especially without accompanying signs of hypoxemia or circulatory compromise.

Choice C rationale

A "quiet chest" following a previous assessment of wheezing in an infant with RSV is an ominous sign. Wheezing is caused by air moving through constricted airways. A sudden cessation of wheezing, despite persistent respiratory distress, suggests severe bronchoconstriction and impending respiratory failure, as airflow has become so minimal that it no longer produces audible sounds.

Choice D rationale

An oxygen saturation of 90% is below the acceptable normal range (typically 95-100%) and indicates hypoxemia, requiring attention and intervention. However, while concerning, it is not as immediately life-threatening as a "quiet chest" which signals impending respiratory arrest due to absent air movement.

Choice A rationale

There is no specific scientific rationale requiring extra vitamin C supplementation while on isoniazid. Isoniazid can cause pyridoxine (vitamin B6) deficiency, which leads to peripheral neuropathy, due to its chemical structure interfering with pyridoxal phosphate metabolism. Therefore, vitamin B6 supplementation is routinely prescribed to prevent this adverse effect, rather than vitamin C, which is not directly involved in this metabolic pathway.

Choice B rationale

Taking isoniazid with milk or juice is generally discouraged as it can interfere with drug absorption. Isoniazid absorption is optimized in an acidic environment and can be reduced by food, particularly dairy products, which can chelate the drug or alter gastric pH. Therefore, consuming it with milk or juice might decrease its bioavailability, leading to sub-therapeutic drug levels and potentially compromising treatment efficacy against Mycobacterium tuberculosis.

Choice C rationale

Isoniazid absorption is best on an empty stomach because food, especially high-fat meals, can significantly decrease its bioavailability. The presence of food in the stomach can delay gastric emptying and interfere with the dissolution and absorption of the drug from the gastrointestinal tract. Optimal absorption ensures that therapeutic drug concentrations are achieved in the bloodstream, which is crucial for effectively inhibiting bacterial cell wall synthesis in Mycobacterium tuberculosis.

Choice D rationale

Isoniazid is not known to cause permanent staining of contact lenses. This side effect is associated with rifampin, another antituberculosis drug, which can cause reddish-orange discoloration of body fluids, including tears, urine, and sweat, due to its chromophore properties and excretion pathways. Isoniazid's mechanism of action and metabolic breakdown do not produce colored metabolites that would result in such staining.