VQ Ratio

Normal V (ventilation) is 4 L of air per minute.
Normal Q (perfusion) is 5L of blood per minute.
- So Normal V/Q ratio is 4/5 or 0.8.
When the V/Q is higher than 0.8, it means ventilation exceeds perfusion.
When the V/Q is < 0.8, there is a VQ mismatch caused by poor ventilation.