Write about Bohr Equation here.

The Bohr equation is used to derive physiological dead space.  

It may be calculated using the results from an arterial blood gas and End tidal CO₂.  

Refer to a respiratory physiology text book for an exlanation of how to derive the equation (A-Z of Anaesthesia and Intensive Care).

V_D       =      P_aCO₂ – P_ETCO₂ 

V_T                      P_aCO₂ 

V_D    =    Dead space 

V_T    =    Tidal volume

P_aCO₂    =    Arterial CO₂

P_ETCO₂    =    End tidal CO₂