Respiratory minute volume

With minute ventilation or breathing time volume is in the fields of medicine and physiology refers to the volume of breathing air that is, on and off again exhaled per unit time here in a minute.

An adult breathes about 12-15 times per minute. He inhaled per breath an a tidal volume of 500-700 ml. Thus his respiratory minute volume is an average of eight liters ( 13 x 600 ml = 7800 ml).

These values ​​are used for example for setting a breathing machine or consumption of an oxygen plant.

Measurement

The respiratory minute volume is measured in the pulmonary function test. It is relatively easy to calculate from the respiratory rate and tidal volume.

Minute ventilation = tidal volume x respiratory rate

In respiration machines, a target value and an actual value of the tidal volume is measured and displayed. In addition, you can often still the spontaneous ( paid by the patient ), respiratory minute volume and the volume delivered by the engine are different. Furthermore, the tidal volume is compared with the inhalation with the tidal volume exhalation, a way of detecting a leakage volume can.

Minute ventilation during exercise

The respiratory minute volume can be increased by physical effort on the three-to fourfold. In well- trained athletes, the maximum AMV can increase to up to 15 times the initial value.

Increase in respiratory minute volume (MV )

The AMV is increased during exercise. In addition, there are pathological conditions that increase the AMV:

  • Each hyperventilation is associated with increased respiratory minute volume, as in fever
  • High altitude or thin air
  • Pulmonary embolism
  • Metabolic acidosis ( acidification of the blood ), which is compensated by hyperventilation.
  • Disorders of the respiratory center

Decreased respiratory minute volume

In sleep the respiratory minute volume falls again from among the days resting value.

  • Under the administration of sedative, it comes at a higher dose to the sinking of the MV.
  • In people who are chronically adapted to an increased carbon dioxide value, administration of oxygen can lead to a decrease in the AMV.
  • Damage to the respiratory center may also lower the AMV.

Lowered respiratory minute volume is also known as hypoventilation.

  • Breathing
  • Physiological size
Unit of time
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