Question

The acid-base status of a patient is as follows: pH 7.45, pCO2 30 mm Hg, pO2 105 mm Hg. The patient has partially compensated:

• A. Metabolic acidosis
• B. Metabolic alkalosis
• C. Respiratory acidosis
• D. Respiratory alkalosis

Hint:

High-normal pH with a low pCO2 driving the change.

Answer 1

The Correct Option is D

Step 1: Read the pH. A pH of 7.45 is at the upper end of normal, indicating an alkalemic tendency, so the primary process is an alkalosis.
Step 2: Examine the respiratory component. The pCO2 is low at 30 mm Hg (normal about 35 to 45). A low pCO2 raises the pH, so the low pCO2 is itself the cause of the alkalosis. This makes the primary disorder a respiratory alkalosis (hyperventilation blowing off CO2).
Step 3: Assess compensation. The pH is only at the high-normal edge rather than markedly elevated, indicating metabolic compensation (renal bicarbonate loss) is partly returning the pH toward normal, hence partially compensated.
Step 4: Conclusion. Low pCO2 driving an alkalemic pH that is being pulled back toward normal is partially compensated respiratory alkalosis.
The medically correct and printed answer is option 4.