A patient has a tidal volume of 050 L a frequency of breathi

A patient has a tidal volume of 0.50 L, a frequency of breathing or respiratory rate of 19.0 breaths/min, and an anatomical dead space volume of 0.20 L. Calculate the alveolar ventilation rate.

Solution

The alveolar ventilation (V_A) and the dead space ventilation/volume (V_D) together combine to form pulmonary ventilation rate (V). So, V = V_A + V_D or V_A = V - V_D

The pulmonary ventilation rate is given by, V = V_T x f

Where V_T = Tidal volume and f = Respiratory Rate

Here we know, V_T = 0.5 and f = 19. So, V = 0.5*19 = 9.5 L

We are given that V_D = 0.2 L, So, V_A = 9.5 - 0.2 = 9.3 L

Hence, V_A i.e. Alveolar Ventilation rate is 9.3 L/min