Question

An arterial blood gas report indicates the client's pH is 7.25, PCO₂ is 35 mm Hg, and HCO₃ is 20 mEq/L. Which disturbance should the nurse identify based on these results?

a. Metabolic acidosis
b. Metabolic alkalosis
c. Respiratory acidosis
d. Respiratory alkalosis

Answer 1

The laboratory results with a pH of 7.25, PCO₂ at 35 mm Hg, and HCO₃ at 20 mEq/L indicate the presence of metabolic acidosis. The pH reflects an acidic state, the normal PCO₂ rules out respiratory acidosis, and the decreased HCO₃ confirms a metabolic cause. Therefore, the correct option is a.

Step-by-step explanation:

The arterial blood gas report you mentioned indicates a client with a pH of 7.25, a PCO₂ of 35 mm Hg, and an HCO₃ of 20 mEq/L. These values suggest a primary acid-base imbalance identified as metabolic acidosis. A pH less than 7.35 is indicative of acidosis, while the normal PCO₂ rules out primary respiratory acidosis. However, the lowered HCO₃ level confirms the metabolic nature of the acidosis.

In metabolic acidosis, the lowered HCO₃ suggests that the kidneys are not excreting acid or producing bicarbonate as needed, or that bicarbonate has been lost due to other reasons such as diarrhea. Although PCO₂ is within the normal range, indicating no primary respiratory problems, if compensation were occurring, we might expect the PCO₂ to be slightly lower due to hyperventilation caused by respiratory efforts to decrease carbonic acid levels.