What is the typical inspiratory duration for artificial ventilations to produce adequate chest rise?

• A. About 0.25 seconds
• B. About 2 seconds
• C. About 3 seconds
• D. About 1 second

Answer: (D)

Deliver the breath over about one second. In an average adult, an inspiratory duration of roughly 1 second provides enough time to deliver an adequate tidal volume so the chest visibly rises, while keeping airway pressures reasonable. This fits with delivering about 10–12 breaths per minute (I:E ratio near 1:2). Ventilating much faster (0.25 seconds) often yields insufficient volume and poor chest rise; ventilating much longer (2 seconds or more) increases the risk of high pressures, gastric insufflation, and decreased venous return. Chest rise is the real-time cue that the breath has the right volume.