Which ventilator parameter helps maintain functional residual capacity and recruits atelectatic alveoli for gas exchange?

Which ventilator parameter helps maintain functional residual capacity and recruits atelectatic alveoli for gas exchange?

• A. Positive end-expiratory pressure (PEEP)
• B. Peak inspiratory pressure
• C. Tidal volume
• D. Fraction of inspired oxygen (FiO2)

Answer: (A)

Positive end-expiratory pressure maintains a positive pressure in the lungs at the end of each exhale, which keeps small airways and alveoli from collapsing. By preventing this collapse, functional residual capacity is increased and previously collapsed (atelectatic) alveoli are kept open or recruited for gas exchange. With more alveoli participating in oxygen and carbon dioxide exchange, overall gas exchange improves—this is especially important in neonates who are prone to alveolar collapse due to surfactant deficiency. Peak inspiratory pressure refers to the maximum pressure during inspiration and mainly influences how forcefully air is delivered, not the end-expiratory airway patency. Tidal volume determines how much air is delivered per breath but does not specifically maintain lung volume at the end of expiration. Fraction of inspired oxygen changes the concentration of oxygen in the delivered air, improving oxygen content but not directly keeping alveoli open or recruiting collapsed units.

Positive end-expiratory pressure maintains a positive pressure in the lungs at the end of each exhale, which keeps small airways and alveoli from collapsing. By preventing this collapse, functional residual capacity is increased and previously collapsed (atelectatic) alveoli are kept open or recruited for gas exchange. With more alveoli participating in oxygen and carbon dioxide exchange, overall gas exchange improves—this is especially important in neonates who are prone to alveolar collapse due to surfactant deficiency.

Peak inspiratory pressure refers to the maximum pressure during inspiration and mainly influences how forcefully air is delivered, not the end-expiratory airway patency. Tidal volume determines how much air is delivered per breath but does not specifically maintain lung volume at the end of expiration. Fraction of inspired oxygen changes the concentration of oxygen in the delivered air, improving oxygen content but not directly keeping alveoli open or recruiting collapsed units.