What ventilatory parameter is altered to increase alveolar ventilation?

• A. Tidal volume
• B. PEEP
• C. Respiratory rate
• D. Flow rate

Answer: (A)

Increasing alveolar ventilation involves enhancing the amount of fresh air that reaches the alveoli, where gas exchange occurs. Tidal volume, which is the volume of air inhaled or exhaled with each breath, is a key factor in this process. By increasing the tidal volume, a larger amount of air is brought into the lungs with each respiratory cycle, thereby increasing the volume available for gas exchange in the alveoli.

This is particularly important in ventilated patients who may have conditions affecting their ability to take deep breaths independently. Although respiratory rate could be adjusted to influence minute ventilation, which includes both tidal volume and respiratory rate, the direct effect on the depth of each breath is most clearly seen through adjustments in tidal volume. The combination of these factors can optimize overall ventilation and improve oxygenation and carbon dioxide elimination in patients.

PEEP primarily affects the end-expiratory lung volume and helps prevent alveolar collapse but does not directly increase the tidal volume for each breath. Flow rate pertains to how quickly air is delivered to the patient but does not directly correlate with the volume of air per breath. Therefore, focusing on tidal volume as a parameter for increasing alveolar ventilation is the most direct approach.