What outcome may occur due to high tidal volume in volume control settings?

• A. Increased patient comfort
• B. Increased risk of high VQ mismatch
• C. Reduced work of breathing
• D. Enhanced oxygenation

Answer: (B)

Using high tidal volumes in volume control ventilation settings can lead to an increased risk of high V/Q (ventilation/perfusion) mismatch. This occurs because large tidal volumes can over-distend alveoli, affecting their ability to properly exchange gases. When certain areas of the lung become over-inflated, they may also reduce blood flow to those areas, thus leading to mismatched ventilation and perfusion where some regions are ventilated well but poorly perfused, or vice versa. This imbalance can hinder effective oxygenation and can lead to further complications in patients, particularly those with pre-existing lung conditions or reduced lung compliance. The focus on maintaining lower tidal volumes where appropriate helps reduce this risk and optimizes overall ventilation effectiveness.

Other outcomes, such as increased patient comfort, reduced work of breathing, and enhanced oxygenation, do not typically result from the use of high tidal volumes, especially in patients who might already be struggling with ventilation. In contrast, managing tidal volumes carefully within recommended ranges is crucial in mechanical ventilation strategies to improve patient outcomes.