How is metabolic acidosis evaluated
What is the general approach to metabolic acidosis evaluation?
Metabolic acidosis can be thought of as comprising two major subgroups: one underpinned by the addition of [H + ] and the other driven by the loss of NaHCO 3 .
The distinction here is generally guided by the calculation of the anion gap.
Prior to this, however, it is prudent to identify and manage underlying threats to the patient’s life consequent to the acidosis. In addition, therapy for the acidosis may unmask adverse effects that should be anticipated.
Examples will be considered later on in this chapter, during the discussion of specific disorders.
Lastly, when able, assess the adequacy of the BBS by comparing the arterial and venous tensions of CO 2 .
Therapy directed at lowering arterial PaCO 2 should be instituted if there is concomitant respiratory failure, and tissue perfusion should be enhanced if there is a gradient (i.e., more than 10 mm Hg) between the PaCO 2 and PvCO 2 .
As noted previously, lowering the venous and therefore capillary CO 2 shifts equation 3 rightward. In this way, bicarbonate rather than tissue proteins buffer the excess protons.
