In ARDSnet guidelines, what tidal volume per kilogram of predicted body weight is commonly used for protection?

• A. About 6 ml/kg PBW
• B. About 10 ml/kg PBW
• C. About 12 ml/kg PBW
• D. About 4 ml/kg PBW

Answer: (A)

Lung-protective ventilation relies on using a small tidal volume based on predicted body weight to prevent overdistension of injured lungs. The predicted body weight reflects lung size more accurately than actual weight, so the goal is to set roughly 6 ml of air per kilogram of PBW. This target came from ARDS studies showing better outcomes with low tidal volumes than with traditional higher volumes, and it helps keep plateau pressures around or below 30 cm H2O to minimize ventilator-induced lung injury. Higher volumes, such as about 10–12 ml/kg PBW, have been linked to more lung injury and worse outcomes, while very low volumes (around 4 ml/kg PBW) are not as commonly used in practice because they can cause problematic hypercapnia and other issues. So the commonly used protective tidal volume is about 6 ml/kg predicted body weight.