During bag-valve-mask ventilation, what is the recommended inspiratory volume for one second?

• A. 400 mL
• B. 600 mL
• C. 800 mL
• D. 1000 mL

Answer: (B)

Bag-valve-mask ventilation should deliver a generous yet controlled tidal volume for each breath, enough to inflate the lungs without pushing air into the stomach. For an average adult, this equates to about 6–7 mL per kilogram of body weight, which commonly translates to roughly 600 mL per breath when delivered over about one second. This one-second inspiratory time helps create adequate ventilation while minimizing high peak pressures and the risk of gastric inflation. If the volume is too low (for example, around 400 mL), ventilation may be ineffective; if it’s too high (800–1000 mL), you increase the risk of gastric insufflation, vomiting, and barotrauma. So delivering about 600 mL in one second is the optimal balance for an adult.