Neonatal Nurse Practitioner Practice Exam

What is the primary effect of lung recoil during exhalation in ventilatory support?

1. Passive inflation of the lungs

2. Active clearance of carbon dioxide

3. Facilitation of gas exchange

4. Resumption of normal respiratory mechanics

The correct answer is: Passive inflation of the lungs

During exhalation in ventilatory support, lung recoil plays a crucial role in the mechanics of breathing. The primary effect of lung recoil is that it allows for the passive deflation of the lungs. This recoil results from the elastic properties of the lung tissue and surface tension within the alveoli, which cause the lungs to return to their resting volume after being inflated. When the lungs are inflated, either through spontaneous breathing or medical ventilation, they stretch, and upon the removal of this inflation, the natural elasticity of the lung tissue works to push air out. This passive process is critical in maintaining normal respiratory function, especially in patients receiving ventilatory support. While options like active clearance of carbon dioxide and facilitation of gas exchange are integral aspects of respiratory function, these processes primarily occur during the inhalation and exhalation cycles rather than being direct primary effects of lung recoil. Similarly, resumption of normal respiratory mechanics implies a broader context that encompasses both inhalation and exhalation, making it less specific than the clear, direct impact of lung recoil on passive inflation.