A nurse is preparing to give an antibiotic to a patient who reports being allergic to antibiotics. Before giving the medication, what will the nurse do first?

Choice A reason: Metabolic acidosis involves low pH (<7.35) and low HCO3- (<22 mEq/L). Here, pH is 7.48 (alkalotic) and HCO3- is 29 mEq/L (high), indicating alkalosis, not acidosis. PaCO2 (44 mm Hg) is normal, ruling out respiratory causes, making this choice incorrect.

Choice B reason: pH 7.48 (high), PaCO2 44 mm Hg (normal), and HCO3- 29 mEq/L (high) indicate metabolic alkalosis, likely from conditions like vomiting or diuretic use, increasing bicarbonate. No respiratory compensation (normal PaCO2) confirms uncompensated metabolic alkalosis, making this the correct choice.

Choice C reason: Respiratory acidosis requires high PaCO2 (>45 mm Hg) and low pH. Here, PaCO2 is 44 mm Hg (normal) and pH is 7.48 (alkalotic), with high HCO3-, pointing to a metabolic cause, not respiratory, making this choice incorrect for the ABG values.

Choice D reason: Respiratory alkalosis involves low PaCO2 (<35 mm Hg) and high pH. With PaCO2 at 44 mm Hg (normal) and high HCO3- (29 mEq/L), the alkalosis is metabolic, not respiratory. This choice doesn’t match the ABG profile, making it incorrect.

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.