Which statement about chronic respiratory acidosis is false?

• A. CO2 retention occurs
• B. Bicarbonate increases due to renal compensation
• C. There is no metabolic compensation
• D. The pH remains low but less severe than in acute cases

Answer: (C)

In chronic respiratory acidosis, CO2 remains elevated because ventilation impairment persists, causing ongoing CO2 retention. Over time, the kidneys compensate by increasing bicarbonate reabsorption and generation, which raises the serum HCO3- and helps bring the pH closer to normal. The pH stays acidotic, but the degree of acidity is less severe than in the acute form due to this metabolic (renal) compensation. Therefore, the statement that there is no metabolic compensation is false—the kidney’s response is the hallmark of the chronic stage. The other points are true: CO2 retention occurs, bicarbonate increases with renal compensation, and the pH, while still low, is less severe than in acute cases.