Given: 22 yr old man Dyspneic Pulmonary function values: Vital capacity (supine) 650mL Minute ventilation...

The tidal volume times the respiration rate must equal the minute ventilation.

So since the minute ventilation is 6 L/min and the respiration rate is 30/min, the tidal volume must be:
`TV = (6 L/min)/(30/min) = 0.2 L` ` `

The total tidal volume of this person's lungs is 0.2 liters. To find the alveolar ventilation, we need to determine how much of this volume of air is actually processed to extract oxygen.

They tell us to use the normal value for dead space, which is approximately 100 mL for someone lying supine.

Thus we can estimate that the alveolar volume is about 100 mL, and so the alveolar ventilation is simply that times the respiration rate:
`AV = (100 mL) * (30/min) = 3 L/min`
The alveolar ventilation is about 3 liters per minute.