Normal PaCO2 range?

Normal PaCO2 range?

• A. 25-35
• B. 30-60
• C. 35-45
• D. 40-50

Answer: (C)

PaCO2 is the arterial carbon dioxide pressure and reflects how well ventilation is removing CO2 produced by metabolism. The normal range is about 35–45 mmHg. This tight range exists because the body maintains acid-base balance by adjusting alveolar ventilation to keep PaCO2 near baseline; too little ventilation raises PaCO2 (respiratory acidosis), while too much ventilation lowers it (respiratory alkalosis). Among the options, 35–45 mmHg fits the standard laboratory reference for a normal PaCO2, making it the best choice. Values lower than 35 indicate hyperventilation, while values above 45 indicate hypoventilation.

PaCO2 is the arterial carbon dioxide pressure and reflects how well ventilation is removing CO2 produced by metabolism. The normal range is about 35–45 mmHg. This tight range exists because the body maintains acid-base balance by adjusting alveolar ventilation to keep PaCO2 near baseline; too little ventilation raises PaCO2 (respiratory acidosis), while too much ventilation lowers it (respiratory alkalosis).

Among the options, 35–45 mmHg fits the standard laboratory reference for a normal PaCO2, making it the best choice. Values lower than 35 indicate hyperventilation, while values above 45 indicate hypoventilation.