Cause:Respiratory failure, inability to breath adequately; rapid onset of coma relative to pH, compared to metabolic acidosis, since CO2 penetrates CSF readily and raises pH rapidly (F. Plum—Nejm 1967;277:605); CO2 also diffuses into all tissues including myocardium, rapidly leads to electromechanical dissociation (EMD), hence HCO3 rx of arrest unwise no matter what blood gases are; arterial gases are misleading too (Nejm 1986;315:153)
see Figure 17.1 for description of Metabolic and Respiratory Components of Acid-Base Balance