How to assess the adequacy of the bicarbonate buffer system?
A high tension of capillary CO 2 within skeletal muscle will lead to a failure to maintain rightward shift, thus extinguishing the BBS. CO 2 tension within muscle capillaries can be assessed with a venous blood gas (VBG). This is because the PCO 2 in capillaries of skeletal muscle reflects the PCO 2 in its cells and interstitial space; further, there is no CO 2 added once the blood leaves the capillaries and enters the veins. The secret here is that if the partial pressure of carbon dioxide in the venous effluent (PvCO 2 ) is high, the BBS in skeletal muscle is less effective (i.e., the rightward direction of equation 3 is blunted). Acidemia will be more pronounced, as more of the H + load will be titrated in vital organs.
