Healthy lungs versus COPD lungs differ in the way they handle CO2. Which statement is correct?

Healthy lungs versus COPD lungs differ in the way they handle CO2. Which statement is correct?

• A. Healthy lungs exhale CO2; COPD patients retain CO2.
• B. COPD exhale CO2 more completely.
• C. Both exhale CO2 identically.
• D. COPD lungs produce more oxygen.

Answer: (A)

The main concept is how CO2 is removed from the body and how COPD changes that process. In healthy lungs, each breath effectively removes CO2 via normal alveolar ventilation. COPD disrupts airflow through narrowed airways, air trapping, and a lot of dead space, which reduces the amount of CO2 that can be exhaled with each breath and creates a mismatch between ventilation and blood flow. As a result, CO2 tends to accumulate in the blood (hypercapnia) rather than being fully expelled. That’s why the statement that healthy lungs exhale CO2 while COPD patients tend to retain CO2 is correct. The idea that COPD exhale CO2 more completely isn’t accurate, and that both lungs exhale CO2 identically or that COPD somehow produces more oxygen doesn’t fit the physiology of impaired ventilation and gas exchange.

The main concept is how CO2 is removed from the body and how COPD changes that process. In healthy lungs, each breath effectively removes CO2 via normal alveolar ventilation. COPD disrupts airflow through narrowed airways, air trapping, and a lot of dead space, which reduces the amount of CO2 that can be exhaled with each breath and creates a mismatch between ventilation and blood flow. As a result, CO2 tends to accumulate in the blood (hypercapnia) rather than being fully expelled. That’s why the statement that healthy lungs exhale CO2 while COPD patients tend to retain CO2 is correct. The idea that COPD exhale CO2 more completely isn’t accurate, and that both lungs exhale CO2 identically or that COPD somehow produces more oxygen doesn’t fit the physiology of impaired ventilation and gas exchange.