A paramedic calls to report to the emergency center nurse about a person who was found unconscious due to opiate overdose. What acid-base imbalance does the nurse anticipate in order to prepare to receive the person?

Choice A reason: Respiratory alkalosis involves low PaCO2 and high pH due to hyperventilation, often from anxiety or hypoxia. In opiate overdose, respiratory depression slows breathing, retaining CO2, not expelling it, making this imbalance unlikely, as it contradicts the hypoventilation caused by opiates. Choice B reason: Respiratory acidosis occurs in opiate overdose due to respiratory depression, reducing ventilation and increasing PaCO2. This elevates carbonic acid, lowering pH. The nurse anticipates this imbalance, preparing for ventilatory support to correct CO2 retention and restore acid-base balance, critical in preventing further hypoxia. Choice C reason: Metabolic acidosis may occur in prolonged opiate overdose due to lactic acidosis from hypoxia, but respiratory acidosis is primary due to immediate CO2 retention from hypoventilation. The nurse prioritizes addressing respiratory depression, as it directly causes the acid-base imbalance in this acute scenario. Choice D reason: Metabolic alkalosis involves high bicarbonate and pH, often from vomiting or diuretic use, not opiate overdose. Opiates cause respiratory depression, leading to CO2 retention and acidosis, not alkalosis, making this imbalance irrelevant for the anticipated pathophysiology in this emergency situation.