T/F: Patients with chronic respiratory acidosis will retain CO2 as bicarbonate and therefore have increased bicarbonate.

• A. True
• B. False
• C. Not sure
• D. Both

Answer: (A)

Chronic respiratory acidosis triggers renal metabolic compensation. When CO2 remains elevated, the kidneys respond by increasing bicarbonate reabsorption and generating new bicarbonate, while excreting more hydrogen ions. This raises serum bicarbonate levels, helping to raise the pH toward normal even though CO2 is still high. In short, the elevated bicarbonate you see in chronic cases is a result of renal compensation, so the statement is true. In contrast, acute cases show only a small, initial rise in bicarbonate before full compensation develops.