Neonatal Nurse Practitioner Practice Exam

Following surfactant therapy for respiratory distress syndrome, what is the primary reason for anticipated improvement in oxygenation?

1. Enhanced matching of ventilation and perfusion

2. Improved lung compliance

3. Lower surface tension

4. Increased tidal volume

The correct answer is: Enhanced matching of ventilation and perfusion

The primary reason for anticipated improvement in oxygenation following surfactant therapy for respiratory distress syndrome is improved lung compliance. Surfactant plays a crucial role in reducing surface tension within the alveoli. When surfactant is administered, it lowers the surface tension, allowing for better expansion of the alveoli during inhalation. This enhanced lung compliance leads to an increased capacity for gas exchange, allowing more oxygen to be transferred into the bloodstream and reducing the work of breathing. While matching of ventilation and perfusion is important for optimal gas exchange, the direct mechanism by which surfactant therapy improves oxygenation is primarily through increasing lung compliance, which facilitates better ventilation. Lower surface tension is indeed a consequence of surfactant therapy, but the critical outcome is the improvement in lung mechanics, allowing the neonatal patient to achieve better oxygenation more effectively. In summary, the introduction of surfactant leads to a more favorable respiratory environment, improving overall lung function and oxygenation capacity, which is essential for infants suffering from respiratory distress syndrome.