A patient specimen shows increased pCO2, decreased pO2, and decreased pH. This pattern is most consistent with:

• A. Acidosis
• B. Alkalosis
• C. Normal
• D. Mixed disorder

Answer: (A)

This pattern tests interpreting arterial blood gas to identify an acid-base disorder. A decreased pH indicates acidemia. A high pCO2 shows that carbon dioxide is retained, which lowers pH by forming carbonic acid—pointing to a respiratory cause. The accompanying low pO2 indicates poor oxygenation, which often accompanies impaired ventilation. Put together, these signs describe respiratory acidosis with hypoxemia. Alkalosis would require a high pH, and normal would not show acidemia with elevated CO2. A mixed disorder isn’t suggested because the elevated CO2 clearly points to a respiratory rather than a metabolic issue. Therefore, the finding is best described as acidosis due to elevated CO2 (respiratory acidosis).