Minute ventilation is the ratio between inhaled and exhaled volume of air during one minute. The average minute of ventilation depends on gender, age, and weight, and makes up 8 -10 l/min for a person weighing 70 kg.
Respiratory minute volume (or minute ventilation or
minute volume) is the volume of gas inhaled (inhaled minute volume) or exhaled
(exhaled minute volume) from a person's lungs per minute. It is an important
parameter in respiratory medicine due to its relationship with blood carbon
dioxide levels. It can be measured with devices such as a Wright respirometer
or can be calculated from other known respiratory parameters. Although minute
volume can be viewed as a unit of volume, it is usually treated in practice as
a flow rate (given that it represents a volume change over time).
Determination of minute volume
Minute volume can either be measured directly or
calculated from other known parameters.
Measurement of minute volume
Minute volume is the amount of gas inhaled or exhaled
from a person's lungs in one minute. It can be measured by a Wright
respirometer or other device capable of cumulatively measuring gas flow, such
as mechanical ventilators.
Calculation of minute volume.
If both tidal volume (VT) and respiratory rate
(ƒ or RR) are known, minute volume can be calculated by
multiplying the two values. One must also take care to consider the effect of
dead space on alveolar ventilation, as seen below in "Relationship to
other physiological rates".
VE=VT*f (l/min)
Physiological significance of minute volume.
Blood carbon dioxide (PaCO2) levels generally vary
inversely with minute volume. For example, a person with increased minute
volume (e.g. due to hyperventilation) should demonstrate a lower blood carbon
dioxide level. The healthy human body will alter minute volume in an attempt to
maintain physiologic homeostasis. A normal minute volume while resting is about
5–8 liters per minute in humans [1]. Minute volume generally decreases when at
rest, and increases with exercise. For example, during light activities minute
volume may be around 12 litres. Riding a bicycle increases minute ventilation
by a factor of 2 to 4 depending on the level of exercise involved. Minute
ventilation during moderate exercise may be between 40 and 60 liters per
minute.[2] [3]
Hyperventilation is the term for having a minute of ventilation higher than physiologically appropriate. Hypoventilation describes a minute volume less than physiologically appropriate.
1. "Avoid
Airway Catastrophes on the Extremes of Minute Ventilation". ACEP
Now. Retrieved 2023-01-11.
2.
^ Zuurbier, M., Hoek, G., van den
Hazel, P., Brunekreef, B. (2009). "Minute ventilation of cyclists, car and bus
passengers: an experimental study". Environmental
Health. 8 (48): 48. doi:10.1186/1476-069x-8-48. PMC 2772854. PMID 19860870.
3. ^ Int Panis, L
(2010). "Exposure to particulate matter in traffic: A comparison of
cyclists and car passengers". Atmospheric Environment. 44 (19):
2263–2270. Bibcode:2010AtmEn..44.2263I. doi:10.1016/j.atmosenv.2010.04.028. S2CID 56142753.
4. https://www.oxfordreference.com/display/10.1093/oi/authority.20110803100200508
Published on 2 May 2024