What was the tidal volume set for the patient in the RDS scenario?

• A. 400 mL
• B. 450 mL
• C. 500 mL
• D. 600 mL

Answer: (C)

In RDS, the ventilator strategy aims for lung-protective tidal volumes, meaning keeping the volume per kilogram relatively low to avoid volutrauma while still supporting gas exchange. The target is typically about 4–6 mL per kilogram of predicted body weight. The 500 mL setting fits this protective range for a patient of this size, because it translates to roughly 6 mL/kg for a typical pediatric weight in this scenario. For example, with a weight around 80 kg, 500 mL equals about 6.25 mL/kg, which is within the desired range. A smaller volume like 400 mL (around 5 mL/kg for the same weight) could be acceptable but might be too low for effective ventilation in this case, whereas a larger volume like 600 mL (around 7.5 mL/kg) edges toward higher tidal volumes that can increase risk of lung injury in stiff lungs. So, 500 mL best balances adequate ventilation with lung protection in this RDS scenario.