This equation computes the alveolar partial pressure of `"CO"_2`.

Inputs

• `V_D` - Dead Space Ventilation, the flow of air in all airways larger than alveoli plus air entering alveoli which does not take part in gas exchange.
• `V_E` - Total Ventilation, the total respiration
• `V_"CO2"` - `"CO"_2` production

Description

This equation characterizes a patient's respiratory rate. Alveolar PCO₂ is directly proportional to the amount of CO₂ produced by metabolism and delivered to the lungs (VCO₂).  At the same time, the PCO₂ is inversely proportional to the alveolar ventilation (VA). The alveolar ventilation is the volume of gas expired from the body (from alveoli) - typically in liters per minute.

It is useful to note that the alveolar and arterial PCO₂ can be assumed to be equal.