What is the main risk associated with excessive tidal volumes in mechanical ventilation?

Excessive tidal volumes in mechanical ventilation pose a significant risk of lung injury due to overstretching. This phenomenon, often referred to as ventilator-induced lung injury (VILI), occurs when the lung parenchyma is subjected to excessive airway pressure and volume, leading to alveolar overdistension. The mechanical stretching can damage the delicate lung tissue, impair the integrity of the alveolar-capillary membrane, and trigger inflammatory processes, which can worsen lung function and oxygenation.

Maintaining appropriate tidal volumes is critical in preventing barotrauma (injury caused by increased pressure) and volutrauma (injury caused by excessive volumes) in the lungs. The ideal approach promotes lung protection, which includes using lower tidal volumes, especially in patients with acute respiratory distress syndrome (ARDS) or other forms of lung injury, to reduce the risk of further damage while supporting adequate ventilation and oxygenation.

In summary, the primary issue with excessive tidal volumes is the potential for serious lung injuries due to the overstretching of lung tissues, making it essential to carefully monitor and adjust ventilatory settings.