Minute Respiratory Volume Equals Respiratory Rate Times Tidal Volume

Minute Respiratory Volume Equals Respiratory Rate Times Tidal Volume

The minute respiratory volume is the total amount of new air moved into the respiratory passages each minute; this is equal to the tidal volume times the res-piratory rate per minute. The normal tidal volume isabout 500 milliliters, and the normal respiratory rate is about 12 breaths per minute. Therefore, the minuterespiratory volume averages about 6 L/min. A personcan live for a short period with a minute respiratory volume as low as 1.5 L/min and a respiratory rate of only 2 to 4 breaths per minute.

The respiratory rate occasionally rises to 40 to 50 per minute, and the tidal volume can become as great as the vital capacity, about 4600 milliliters in a young adult man. This can give a minute respiratory volume greater than 200 L/min, or more than 30 times normal. Most people cannot sustain more than one half to two thirds these values for longer than 1 minute.