A nurse reviews the arterial blood gas results of a client with a pH of 7.48, PaCO2 of 33 mm Hg, and HCO3 of 23 mEq/L. Which acid-base imbalance should the nurse identify, and what is the priority nursing intervention?

Choice A rationale Metabolic acidosis occurs when there is a primary decrease in bicarbonate concentration below 22 mEq/L or an increase in nonvolatile acids within the systemic circulation. This client exhibits a pH of 7.48, which exceeds the normal range of 7.35 to 7.45, indicating alkalosis rather than acidosis. Furthermore, the bicarbonate level of 23 mEq/L is within the normal range of 22 to 28 mEq/L, making a primary metabolic acidotic process scientifically inconsistent with these specific laboratory findings. Choice B rationale Respiratory alkalosis is characterized by a systemic pH above 7.45 and a PaCO2 below the normal range of 35 to 45 mm Hg. This client has a pH of 7.48 and a PaCO2 of 33 mm Hg, confirming this imbalance. Hyperventilation causes excessive loss of carbon dioxide, leading to decreased carbonic acid. Encouraging the client to breathe into a paper bag or using a rebreathing mask helps increase the inhaled CO2, which restores the carbonic acid levels and corrects the pH. Choice C rationale Metabolic alkalosis is defined by a pH greater than 7.45 and a bicarbonate level exceeding 28 mEq/L. While this client is in an alkalotic state, their bicarbonate level of 23 mEq/L is perfectly normal. Therefore, the primary driver is not metabolic in nature. Monitoring for hypokalemia is appropriate in metabolic alkalosis because hydrogen ions shift out of cells while potassium shifts in, but this does not address the respiratory cause of the low PaCO2 observed in this particular client scenario. Choice D rationale Respiratory acidosis is scientifically defined by a pH below 7.35 and a PaCO2 greater than 45 mm Hg. This occurs during hypoventilation when the lungs fail to adequately excrete carbon dioxide, leading to an accumulation of hydrogen ions. This client exhibits a high pH and a low PaCO2, which is the exact physiological opposite of respiratory acidosis. Interventions like assessing airway patency and assisting with ventilation are reserved for patients with hypercapnia and acidemia, not for those with alkalemia.