What is the main reason to avoid high tidal volumes in ARDS?

High tidal volumes in patients with Acute Respiratory Distress Syndrome (ARDS) should be avoided primarily to prevent further injury to ventilated lungs. ARDS is characterized by impaired gas exchange and inflamed lung tissues. Using high tidal volumes can lead to overdistension of the alveoli, further exacerbating lung injury through mechanisms such as barotrauma and volutrauma. It can also cause detrimental effects such as increased shunting and reduced ventilation-perfusion matching, further impairing oxygenation and carbon dioxide removal.

The practice of lung protective ventilation emphasizes low tidal volume strategies (generally around 6 ml/kg of predicted body weight) to minimize these risks and to preserve lung function. This approach allows for adequate ventilation while reducing the likelihood of additional injury to the lungs already compromised by ARDS. Overall, maintaining low tidal volumes is crucial for optimizing patient outcomes and supporting recovery.