What are the two methods used to deliver inspiration?

• A. Time & Speed
• B. Temperature & Humidity
• C. Flow & Resistance
• D. Volume & Pressure

Answer: (D)

Inspiration on a ventilator is delivered mainly in two ways: by volume or by pressure. In volume-targeted delivery, the ventilator delivers a fixed tidal volume with a controlled flow, so each breath delivers the same amount of air regardless of changing airway resistance or lung compliance. In pressure-targeted delivery, the ventilator applies a set inspiratory pressure for a given time, so the actual tidal volume depends on the patient’s lung mechanics. These two approaches define how the breath is generated, whereas the other options refer to gas properties or flow dynamics rather than the fundamental method of delivering inspiration.