Which parameter prevents the ventilator from delivering more than a set amount of air during a breath?

• A. Volume Limit
• B. Flow Cycling
• C. Pressure Limit
• D. Exhalation

Answer: (A)

Volume limit is the parameter that prevents delivering more than a set amount of air during a breath. It sets a maximum tidal volume, and once that volume is reached, the ventilator stops delivering air for that breath, protecting the lungs from overdistension. Flow cycling, by contrast, ends inspiration when inspiratory flow falls below a threshold, so it governs timing more than a hard volume cap. A pressure limit keeps peak airway pressure in check to avoid barotrauma, but the same pressure can produce different volumes depending on lung mechanics. Exhalation is simply the phase of the cycle and does not cap the amount of air delivered in each breath.