A cancer patient asks the nurse what can be given to alleviate severe, chronic pain of several months’ duration. The patient has been taking oxycodone (OxyContin) and states it is no longer effective. The nurse will suggest discussing which medication with the provider?

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: A 25-year-old man typically has mature liver and kidney function, efficiently metabolizing and excreting CNS depressants like benzodiazepines. Toxicity risk is lower compared to neonates, whose immature systems impair drug clearance, making this choice less critical for close toxicity monitoring.

Choice B reason: A 15-year-old boy has relatively mature metabolic pathways, though not fully adult-like. CNS depressants are cleared more effectively than in neonates, reducing toxicity risk. Adolescents are less vulnerable than infants to accumulation, making this choice less concerning for drug toxicity observation.

Choice C reason: A 3-week-old neonate has immature liver enzymes (e.g., CYP450) and reduced renal clearance, increasing the risk of CNS depressant toxicity (e.g., respiratory depression, sedation). Their low body mass and underdeveloped metabolism necessitate close monitoring, making this the correct choice for heightened toxicity vigilance.

Choice D reason: A 25-year-old woman, like men of the same age, typically has efficient drug metabolism and excretion. CNS depressants pose lower toxicity risk compared to neonates, whose immature systems lead to drug accumulation, making this choice less critical for close toxicity monitoring.