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Alveolar Minute Volume Calculator
During a typical inhalation (inspiration), the air breathed into the lungs travels through the conducting zone of the respiratory system (oral and nasal passages, pharynx, glottis, trachea, primary bronchi, smaller bronchioles, and terminal bronchioles) to reach the respiratory zone (respiratory bronchioles and alveoli) where actual exchange of gases can take place between the air within the respiratory bronchioles and alveoli and blood in pulmonary capillaries. Typically, oxygen (O2) moves down its partial pressure gradient out of the alveolar sacs and into the pulmonary capillaries, and carbon dioxide (CO2) moves in the opposite direction down its own partial pressure gradient out of the pulmonary capillaries and into the alveoli. Because the air within the conducting does not contribute to gas exchange, this region of respiratory system is referred to as the dead anatomical space (DAS), also referred to as the anatomical dead space or simply dead space. In a healthy adult human, the volume of air contained within the dead anatomical space is about 150 mL.
Minute volume (also referred to as minute ventilation or respiratory minute volume) is used to determine the total volume of air moved into (inhaled) or out of (exhaled) the lungs per unit time (usually per minute). Minute volume is calculated by multiplying the number of respiratory cycles per minute (typically about 12 breaths per minute) by the volume of gas inhaled or exhaled per respiratory cycle (referred to as tidal volume, which is typically about 500 mL in males and 400 mL in females). Therefore, for an average healthy adult female at rest, minute volume is 4,800 mL/min. For an average healthy adult male at rest, minute volume is 6,000 mL/min. See our Minute Volume Calculator.
As noted above, the entire volume of air moved into the lungs during each inhalation does not come into direct contact with alveoli. In fact, 150 mL of tidal volume remains within the conducting zone (dead anatomical space, DAS) and is not available to contribute to O2 and CO2 gas exchange. Thus, DAS must be subtracted from tidal volume to determine the amount of air that is in contact with the respiratory zone of the lungs (respiratory bronchioles and alveoli). Therefore, alveolar minute volume is used to determine the total volume of air per unit time that is available for gas exchange. Alveolar minute volume is calculated by multiplying the number of breaths per minute by the difference between tidal volume and dead anatomical space. For an average adult male, alveolar minute volume can be calculated to be 4,200 mL/min, or 12 × (500 − 150).
Alveolar minute volume equation

Alveolar minute volume equation

  • Alveolar Minute Volume (AMV) is the volume of air per unit time (usually per minute) that comes into contact with respiratory exchange surfaces of the lungs (respiratory bronchioles and alveoli). It is the portion of inhaled air that participates in gas exchange.
  • Respiratory Rate (R) or breathing rate is the number of respiratory cycles (or breaths) per unit time. It is generally reported as breaths per minute. A full respiratory cycle represents inhalation (inspiration) followed by exhalation (expiration). In adult humans at rest, respiratory rate is about 12 breaths per minute.
  • Tidal Volume (TV) is the volume of air moved into the lungs during inspiration (or inhalation) or the volume of air moved out of the lungs during expiration (or exhalation). At rest, it is about 500 mL for an adult male and about 400 mL for an adult female.
  • Dead Anatomical Space (DAS) is the volume of air contained within the conducting zone of the respiratory system. In a healthy adult individual, it is about 150 mL.
Minute volume calculator
Each calculator cell shown below corresponds to a term in the formula presented above. Enter appropriate values in all cells except the one you wish to calculate. Therefore, at least two cells must have values, and no more than one cell may be blank. The value of the blank cell will be calculated based on the other values entered. After a calculation is performed, the calculated cell will be highlighted and subsequent calculations will calculate the value of the highlighted cell (with no requirement to have a blank cell). However, a blank cell has priority over a highlighted cell.
Breathing rate breaths/minute
per
Tidal volume mL/breath
per
Dead anatomical space mL
   
Minute volume mL/minute
per
        






Posted: Friday, May 10, 2024