In respiratory physiology, ventilation (or ventilation rate) is the rate at which gas enters or leaves the lung. It is categorized under the following definitions:

Measurement Symbol Equation Description
Minute ventilation = tidal volume * respiratory rate[1][2] the total volume of gas entering the lungs per minute.
Alveolar ventilation = (tidal volume - dead space) * respiratory rate [1] the volume of gas per unit time that reaches the alveoli, the respiratory portions of the lungs where gas exchange occurs.
Dead space ventilation = dead space * respiratory rate is the volume of gas per unit time that does not reach these respiratory portions, but instead remains in the airways (trachea, bronchi, etc.).

Sample values[]

Measure Sample value at rest Sample value moderate exercise
Tidal volume 0.5 L 3.0 L
Respiratory rate 12 breaths/minute 30 breaths/minute
Minute ventilation 6.0 L/min 90 L/min
Dead space 0.15 L 0.15 L
Dead space ventilation 1.8 L/min 4.5 L/min
Alveolar ventilation 4.2 L/min 85.5 L/min

Pulmonary ventilation may be evaluated using a breathing tube or spirometer, measuring the movement of the chest and abdominal walls using respiratory inductance plethysmography or by isolating the subject in an enclosed metabolic chamber.

See also[]

  • Gas exchange
  • Fowler method