How does CPAP enhance oxygenation and ventilation?

• A. It removes carbon dioxide from the lungs
• B. It reinforces lung structure and prevents collapse
• C. It forces the alveoli open and pushes oxygen across the alveolar membrane
• D. It increases the rate of blood circulation

Answer: (C)

Continuous Positive Airway Pressure (CPAP) enhances oxygenation and ventilation primarily by forcing the alveoli open and pushing oxygen across the alveolar membrane. This mechanism is crucial for patients with conditions such as obstructive sleep apnea or other respiratory disorders where airway collapse or inadequate ventilation occurs.

By applying a constant level of positive pressure, CPAP keeps the airways open throughout the entire breathing cycle, allowing for improved airflow into the lungs. The increased pressure helps to prevent the collapse of the alveoli during expiration, ensuring that they remain open and available for gas exchange. This promotes better oxygenation of the blood as more surface area of the alveoli is available for the exchange of oxygen and carbon dioxide.

In contrast, while CPAP does have a role in managing carbon dioxide levels due to improved ventilation, its primary function is not to specifically remove carbon dioxide from the lungs. Additionally, although CPAP can prevent the collapse of lung structures, its main contribution is through enhancing ventilation and oxygenation rather than providing structural support. Increasing the rate of blood circulation does not directly relate to the function of CPAP, as it is primarily focused on improving lung function rather than hemodynamic effects.